This work was supported by a grant from the Tabriz University of Medical Sciences (grant no. 61019) to S.S.-E. and a publication grant from LiteCure LLC, Newark, DE, USA to L.D.T. The authors would like to thank the Immunology Department and Education Development Center (EDC) of Tabriz University of Medical Sciences for their kind assistance.

All of the procedures were carried out in conformity with the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health (NIH; Publication No. 85-23, revised 1985) and approved by the regional ethics committee of Tabriz University of Medical Sciences.
CAUTION: This protocol includes the application of Class 3B laser instruments and will require proper training and adherence to safety guidelines. Class 3B lasers can seriously damage the eyes and can heat the skin. Class 3B lasers are not considered a burn hazard. Eye protection goggles must be worn at all times when operating the laser device.
1. Laser light transmission experiments
NOTE: Used here were three 18-month-old male BALB/c mice obtained from the animal facility of Tabriz University of Medical Sciences. A 60 mW laser (660 nm) with a circular beam shape of 2.5 mm in diameter is used as the light source. The laser source produces a circularly polarized light with a Gaussian intensity profile and is operated in continuous wave mode. A commercial photodiode power meter with a 10 nW resolution, a square 1 cm2 photodiode active area, and a spectral response range from 400 to 1100 nm is used to measure the transmitted light power through the samples.
<ol>
	<li>Sample preparation
	<ol>
		<li>In order to obtain fresh samples, deeply anesthetize the mouse with a mixture of ketamine (100 mg/kg) and xylazine (10 mg/kg).</li>
		<li>Dissect the mouse&#39;s head with regular scissors, starting from the point located just above the shoulders.</li>
		<li>Rotate the head so that the ventral side of the jaw faces up. Slide angled dissection scissors smoothly through the oral cavity until the resistance of the mandibular junction is noticed. Cut all large muscles linking the mandible bone to the skull and discard them.</li>
		<li>Remove the palatine bones, using angled dissection scissors.</li>
		<li>Discard all flesh surrounding the skull, using curved forceps.</li>
		<li>Dissect the lower portion of the skull, and then, carefully take the brain out of the remaining skull bone, with a curved spatula.</li>
		<li>Fix the intact brain tissue in a 2% agarose gel so the tissue will be suitable for slicing. 
		NOTE: In order to obtain an intact skull plus scalp sample, the brain tissue should be removed from the ventral side of the animal&#39;s head without any damage to the dorsal portion of the head.</li>
	</ol>
	</li>
	<li>Brain slicing procedure
	<ol>
		<li>Spread a drop of superglue (~0.05 mL) on the surface of the vibratome mounting block.</li>
		<li>Carefully attach the agarose block to the vibratome mounting block so that the ventral surface of the brain is facedown, and adjust its position.</li>
		<li>Slightly match the vibratome blade to the upper surface of the agarose block and record the cutter value as the primary level.</li>
		<li>Fill the vibratome tank with ice-cold normal saline solution.</li>
		<li>Adjust the vibratome parameters (e.g.,&#160;the slice thickness [1 mm], speed [5 of 5 on device unit], and vibration frequency [5 of 5 on device unit]) to obtain satisfactory slicing.</li>
		<li>Cut the brain transversely into a slice with a 1,000 &#181;m thickness. 
		NOTE: The slice is the portion of the brain tissue delimited by the cortical surface and a plane positioned 1,000 &#181;m inferior to the cortical surface (the dorsal hippocampus).</li>
		<li>Add a drop of water (~0.05 mL) on the optical glass surface and put the brain slice on top of it. Then, add a drop of water on the brain slice and carefully place the second optical glass on top of it. 
		NOTE: A drop of water should be added to the sample glass boundaries in order to prevent tissue drying and light scattering from rough surfaces.</li>
	</ol>
	</li>
	<li>Measurement of light transmission through the head tissues
	<ol>
		<li>Set up the optical equipment, including the laser device, reflecting mirrors, and power meter unit. 
		CAUTION: Put on protective eye goggles prior to turning on the laser.</li>
		<li>In the absence of a sample on the power meter, turn on the laser device and focus the laser beam on the mirror that is located at the proper distance for guiding the beam perpendicular to the photodiode&#39;s active area. 
		NOTE: Light transmission measurements must be performed in a darkroom at room temperature (23-25 &#176;C), within 30 min after the head tissues have been extracted.</li>
		<li>Perform measurements on the sliced brain tissue.
		<ol>
			<li>Place two blank optical glasses on the surface of the power meter.</li>
			<li>Read the transmitted light power (I0) from the power meter&#39;s display screen and record the value.</li>
			<li>Gently place the brain sample, which is encompassed by two optical glasses, on the surface of the power meter, focus the beam on the tissue&#39;s respective area, read the transmitted power, and record the value.</li>
		</ol>
		</li>
		<li>Perform measurements on the skull plus the scalp.
		<ol>
			<li>Place a blank optical glass on the surface of the power meter.</li>
			<li>Read the transmitted light power (I0) from the power meter&#39;s display screen and record the value.</li>
			<li>Lightly place an optical glass with fresh skull plus scalp tissue on the surface of the power meter, match the light beam on the bregma zone, read the transmitted power, and record the value.</li>
			<li>In order to maximize the signal-to-noise ratio, repeat the light transmission measurement at least 3x for all samples. 
			NOTE: The bregma zone is placed in an approximately 3 mm rostral to a line drawn through the anterior base of the ears. The thickness of the skull plus scalp tissue is measured by a standard caliper.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
2. Photobiomodulation therapy (PBMT)
NOTE: Forty-five male BALB/c mice assigned to three groups of 15 mice each were used. The groups were composed of young-control mice (2 months old) that received sham-PBMT, aged-control mice (18 months old) that received sham-PBMT, and aged-PBMT mice (18 months old) that received PBMT. The sham-PBMT treatment consisted of treatment identical to the PBMT group but with the laser inactive. Mice were obtained from the animal facility of Tabriz University of Medical Sciences and were housed in the animal holding unit of the Neurosciences Research Center (NSRC) at 24-25 &#176;C and 55% relative humidity, with a 12 h light and 12 h dark photoperiod. Food and water were provided ad libitum. All mice were acclimatized for at least 1 week prior to treatment.
<ol>
	<li>Laser treatment procedure 
	NOTE: A diode GaAlAs laser with continuous wave mode at 660 nm wavelength was used for transcranial PBMT treatment. The laser device was operated at an output power of 200 &#177; 2 mW and an irradiance of 6.66 W/cm2, with a spot size of 0.03 cm2. An average fluence of 99.9 J/cm2 per each session was delivered to the scalp surface for 15 s of irradiation. The irradiation was administered 1x daily for 2 consecutive weeks.
	<ol>
		<li>Bring the mice in their home cages to the therapy room, approximately 20 min prior to beginning the treatment.</li>
		<li>Connect an electric protector to the wall outlet.</li>
		<li>Insert the laser device plug into an electric protector.</li>
		<li>Cover the tip of the laser probe with a transparent nylon film in order to prevent any scratching to the surface.</li>
		<li>Carefully connect the probe to the channel of the laser device.</li>
		<li>Turn on the laser device and wait a few seconds for it to warm up.</li>
		<li>Adjust the laser/treatment parameters, including the irradiation time and operation mode.</li>
		<li>In the absence of any samples, determine the laser average power by contacting the tip of the probe to the active area of the power meter on the laser device. Record the value.</li>
		<li>Repeat the calibration process (step 2.1.8) at least 5x, read the incident powers from the power meter&#39;s display screen, and record the values.</li>
		<li>Gently hold a mouse by the dorsal skin of the animal&#39;s neck in the palm of a hand and immobilize its head. 
		NOTE: In the current protocol, the laser probe is placed on the bregma zone, which is ~3 mm rostral to a line drawn between the internal base of the ears.</li>
		<li>Lightly place the tip of the probe directly on the scalp at the midline, approximately 3 mm rostral to a line drawn through the anterior base of the ears. 
		NOTE: Hold the probe at an approximately 45&#176; angle to the plane of the abdomen.</li>
		<li>In order to avoid direct irradiation to the animal&#39;s eyes, first contact the tip of the probe on the head and, then, turn on the laser device.</li>
		<li>Turn on the laser and stably hold the probe until the completion of the irradiation.</li>
		<li>After the end of the therapy, withdraw the laser probe from the head and gently return the mouse to its cage.</li>
		<li>Turn off the laser device and disconnect the probe from the device.</li>
		<li>Clean the laser probe with an appropriate optical cleaner.</li>
		<li>Transfer the mice to the animal facility.</li>
	</ol>
	</li>
</ol>
3. Behavioral Tasks
<ol>
	<li>Open-field test
	<ol>
		<li>Assess the locomotor activity of each mouse by the total distance traveled during an open-field test, as described previously15.</li>
	</ol>
	</li>
	<li>Barnes maze task
	<ol>
		<li>&#8203;Apparatus 
		NOTE: The spatial learning and memory task is performed in a Barnes maze16. The apparatus used for this neurobehavioral task consists of a circular platform made of black wood (95 cm in diameter) with 20 equidistant, 5 cm-diameter circular holes that are located on the platform, 3 cm from the perimeter. The apparatus is elevated 50 cm from the floor to prevent the animal from climbing down. A movable black plastic escape box (20 cm x 15 cm x 5 cm) is placed under the escape hole. A black maze is used for testing white mice, and a black mat should be placed under the maze when a software tracking system is used.
		<ol>
			<li>Place the maze apparatus in the center of a quiet room with bright overhead lighting.</li>
			<li>Place a &#34;Do Not Enter&#34; sign on the outside of the task room door.</li>
			<li>Attach visual-spatial cues to the perimeter walls.</li>
			<li>Position a digital video camera above the maze platform.</li>
			<li>Clean the surface of the maze platform with 70% ethanol to remove unwanted olfactory cues.</li>
			<li>Add a small amount of bedding from the animal&#39;s home cage to the inside of the escape box to serve as an olfactory cue.</li>
		</ol>
		</li>
		<li>Adaptation session
		<ol>
			<li>Bring each mouse to the task room approximately 30 min prior to beginning the experiment, in order for the mouse to become habituated.</li>
			<li>Remove the mouse from its cage and gently place the animal in the escape box for 1 min.</li>
		</ol>
		</li>
		<li>Training session 
		NOTE: The training session is repeated for each mouse on 4 consecutive days.
		<ol>
			<li>Gently remove the mouse from the escape box.</li>
			<li>Place the mouse in the center of the arena; then, place the start chamber on top of the mouse.</li>
			<li>Remove the start chamber after 10 s, and allow the mouse to explore the arena for 3 min.</li>
			<li>Quietly move to the computer area and put on noise-canceling headphones.</li>
			<li>Trigger a negative auditory stimulus consisting of a loud white noise of approximately 80 dB at the platform level and begin videotaping the mouse.</li>
			<li>Turn off the white noise and stop videotaping when the mouse enters the escape box. Allow the animal to remain undisturbed in the box for 1 min.</li>
			<li>Remove the mouse from the escape box and place it back into its cage.</li>
			<li>Repeat steps 3.4.2 through 3.4.7 4x per day, with 3 min intervals between repeated trials. 
			NOTE: Between all trials, remove any urine or feces from the arena surface and clean the maze with 70% ethanol.</li>
		</ol>
		</li>
		<li>Probe trial session
		<ol>
			<li>Following the last training trial, 24 h later, remove the escape box from the maze platform and repeat steps 3.4.2 through 3.4.5.</li>
			<li>After 3 min, turn off the white noise and stop videotaping. Remove the mouse from the maze arena and place it back into its cage.</li>
			<li>After all the animals have been tested, clean the maze platform and the start chamber. Turn off the room lights and remove the &#34;Do Not Enter&#34; sign from the door.</li>
			<li>Store the video recordings from the testing sessions to an external hard drive for further analysis.</li>
			<li>Set up the video-tracking software program and extract the parameters of interest from the recorded videos, including the latency time to find the target hole during 4 days of training sessions and the time spent in the target quadrant during the probe trial session.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
4. Biochemical assessment
<ol>
	<li>ATP levels in the hippocampus
	<ol>
		<li>Deeply anesthetize each mouse with an intraperitoneal injection of a mixture of ketamine (100 mg per gram of body weight) and xylazine (10 mg per gram of body weight).</li>
		<li>Decapitate the animal and rapidly remove the brain tissue from the skull.</li>
		<li>Dissect out the hippocampus and homogenize the tissue in ice-cold sample buffer (provided by the kit) with a tissue homogenizer.</li>
		<li>Immediately centrifuge the homogenate at 2,000 x g for 3 min at 4 &#176;C.</li>
		<li>Transfer the supernatant to a clean tube.</li>
		<li>Assess the hippocampal ATP levels, using the spectrophotometric method as described previously11.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Chung, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nuts+and+bolts+of+low-level+laser+(light)+therapy.">The nuts and bolts of low-level laser (light) therapy.</a> Annals of Biomedical Engineering. 40 (2), 516-533 (2012).</li><li>Salehpour, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+Photobiomodulation+Therapy:+a+Narrative+Review.">Brain Photobiomodulation Therapy: a Narrative Review.</a> Molecular Neurobiology. , 1-36 (2018).</li><li>Hamblin, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shining+light+on+the+head:+photobiomodulation+for+brain+disorders.">Shining light on the head: photobiomodulation for brain disorders.</a> BBA Clinical. 6, 113-124 (2016).</li><li>Karu, T. I., Pyatibrat, L. V., Kolyakov, S. F., Afanasyeva, N. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Absorption+measurements+of+a+cell+monolayer+relevant+to+phototherapy:+reduction+of+cytochrome+c+oxidase+under+near+IR+radiation.">Absorption measurements of a cell monolayer relevant to phototherapy: reduction of cytochrome c oxidase under near IR radiation.</a> Journal of Photochemistry and Photobiology B: Biology. 81 (2), 98-106 (2005).</li><li>de Freitas, L. F., Hamblin, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proposed+mechanisms+of+photobiomodulation+or+low-level+light+therapy.">Proposed mechanisms of photobiomodulation or low-level light therapy.</a> IEEE Journal of Selected Topics in Quantum Electronics. 22 (3), 348-364 (2016).</li><li>Xuan, W., Vatansever, F., Huang, L., Hamblin, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+low-level+laser+therapy+enhances+learning,+memory,+and+neuroprogenitor+cells+after+traumatic+brain+injury+in+mice.">Transcranial low-level laser therapy enhances learning, memory, and neuroprogenitor cells after traumatic brain injury in mice.</a> Journal of Biomedical Optics. 19 (10), 108003 (2014).</li><li>DeTaboada, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+application+of+low-energy+laser+irradiation+improves+neurological+deficits+in+rats+following+acute+stroke.">Transcranial application of low-energy laser irradiation improves neurological deficits in rats following acute stroke.</a> Lasers in Surgery and Medicine: The Official Journal of the American Society for Laser Medicine and Surgery. 38 (1), 70-73 (2006).</li><li>De Taboada, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+laser+therapy+attenuates+amyloid-&#946;+peptide+neuropathology+in+amyloid-&#946;+protein+precursor+transgenic+mice.">Transcranial laser therapy attenuates amyloid-&#946; peptide neuropathology in amyloid-&#946; protein precursor transgenic mice.</a> Journal of Alzheimer&#8217;s Disease. 23 (3), 521-535 (2011).</li><li>Oueslati, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photobiomodulation+suppresses+alpha-synuclein-induced+toxicity+in+an+AAV-based+rat+genetic+model+of+Parkinson&#8217;s+disease.">Photobiomodulation suppresses alpha-synuclein-induced toxicity in an AAV-based rat genetic model of Parkinson&#8217;s disease.</a> PloS One. 10 (10), e0140880 (2015).</li><li>Xu, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-level+laser+irradiation+improves+depression-like+behaviors+in+mice.">Low-level laser irradiation improves depression-like behaviors in mice.</a> Molecular Neurobiology. 54 (6), 4551-4559 (2017).</li><li>Salehpour, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+low-level+laser+therapy+improves+brain+mitochondrial+function+and+cognitive+impairment+in+D-galactose&#8211;induced+aging+mice.">Transcranial low-level laser therapy improves brain mitochondrial function and cognitive impairment in D-galactose&#8211;induced aging mice.</a> Neurobiology of Aging. 58, 140-150 (2017).</li><li>Grady, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cognitive+neuroscience+of+ageing.">The cognitive neuroscience of ageing.</a> Nature Reviews Neuroscience. 13 (7), 491 (2012).</li><li>Beal, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondria+take+center+stage+in+aging+and+neurodegeneration.">Mitochondria take center stage in aging and neurodegeneration.</a> Annals of Neurology. Official Journal of the American Neurological Association and the Child Neurology Society. 58 (4), 495-505 (2005).</li><li>Lu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-level+laser+therapy+for+beta+amyloid+toxicity+in+rat+hippocampus.">Low-level laser therapy for beta amyloid toxicity in rat hippocampus.</a> Neurobiology of Aging. 49, 165-182 (2017).</li><li>Seibenhener, M. L., Wooten, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+the+open+field+maze+to+measure+locomotor+and+anxiety-like+behavior+in+mice.">Use of the open field maze to measure locomotor and anxiety-like behavior in mice.</a> Journal of Visualized Experiments. (96), e52434 (2015).</li><li>Rosenfeld, C. S., Ferguson, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Barnes+maze+testing+strategies+with+small+and+large+rodent+models.">Barnes maze testing strategies with small and large rodent models.</a> Journal of Visualized Experiments. (84), e51194 (2014).</li><li>Huang, Y. Y., Chen, A. C. H., Carroll, J. D., Hamblin, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biphasic+dose+response+in+low+level+light+therapy.">Biphasic dose response in low level light therapy.</a> Dose Response. 7 (4), 358-383 (2009).</li><li>Mohammed, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+low-level+infrared+laser+irradiation+ameliorates+depression+induced+by+reserpine+in+rats.">Transcranial low-level infrared laser irradiation ameliorates depression induced by reserpine in rats.</a> Lasers in Medical Science. 31 (8), 1651-1656 (2016).</li><li>Zhang, Y., Zhang, C., Zhong, X., Zhu, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+evaluation+of+SOCS-induced+optical+clearing+efficiency+of+skull.">Quantitative evaluation of SOCS-induced optical clearing efficiency of skull.</a> Quantitative Imaging in Medicine and Surgery. 5 (1), 136 (2015).</li><li>Shaw, V. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroprotection+of+midbrain+dopaminergic+cells+in+MPTP-treated+mice+after+near-infrared+light+treatment.">Neuroprotection of midbrain dopaminergic cells in MPTP-treated mice after near-infrared light treatment.</a> Journal of Comparative Neurology. 518 (1), 25-40 (2010).</li><li>Moro, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photobiomodulation+inside+the+brain:+a+novel+method+of+applying+near-infrared+light+intracranially+and+its+impact+on+dopaminergic+cell+survival+in+MPTP-treated+mice.">Photobiomodulation inside the brain: a novel method of applying near-infrared light intracranially and its impact on dopaminergic cell survival in MPTP-treated mice.</a> Journal of Neurosurgery. 120 (3), 670-683 (2014).</li><li>Reinhart, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+behavioural+and+neuroprotective+outcomes+when+670+nm+and+810+nm+near+infrared+light+are+applied+together+in+MPTP-treated+mice.">The behavioural and neuroprotective outcomes when 670 nm and 810 nm near infrared light are applied together in MPTP-treated mice.</a> Neuroscience Research. 117, 42-47 (2017).</li><li>Sadowski, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amyloid-&#946;+deposition+is+associated+with+decreased+hippocampal+glucose+metabolism+and+spatial+memory+impairment+in+APP/PS1+mice.">Amyloid-&#946; deposition is associated with decreased hippocampal glucose metabolism and spatial memory impairment in APP/PS1 mice.</a> Journal of Neuropathology and Experimental Neurology. 63 (5), 418-428 (2004).</li></ol>

P.C.&#39;s salary was supported by the Harvard Psychiatry Department (Dupont-Warren Fellowship and Livingston Award), by the Brain and Behavior Research Foundation (NARSAD Young Investigator Award), and by the Photothera Inc. unrestricted grant. The drug donation came from TEVA. Travel reimbursement came from Pharmacia-Upjohn. P.C. has received consultation fees from Janssen Research and Development. P.C. has filed several patents related to the use of near-infrared light in psychiatry. PhotoMedex, Inc. supplied four devices for a clinical study. P.C. has received unrestricted funding from Litecure Inc. to conduct a study on transcranial photobiomodulation for the treatment of major depressive disorders and to conduct a study on healthy subjects. P.C. cofounded a company (Niraxx Light Therapeutics) focused on the development of new modalities of treatment based on near-infrared light; he is also a consultant for the same company. P.C. received funding from Cerebral Sciences to conduct a study on transcranial photobiomodulation for generalized anxiety disorder. The other authors have no conflicts of interest to disclose.

We describe a protocol for conducting a transcranial PBMT procedure in mice. This protocol is specifically targeted to neuroscience laboratories that perform photobiomodulation research focused on rodents. However, this protocol can be adapted to other laboratory animals that are frequently used in the neuroscience field, such as rabbit, cat, dog, or monkey.
Currently, there is increased interest in investigating transcranial PBMT with red/NIR lasers and LEDs. In order to successfully carry ou...

PBMT, or low-level laser light therapy (LLLT), is a general term which refers to therapeutic methods based on the stimulation of biological tissues by light energy from lasers or light-emitting diodes (LEDs). Almost all PBMT treatments are applied with red to near-infrared (NIR) light at wavelengths from 600 to 1100 nm, an output power ranging from 1 to 500 mW, and a fluence ranging from &#60;1 to &#62;20 J/cm2 (see Chung et al.1).
Transcranial PBMT is a noninvasive light delivery method that is conducted by irradiation of the head using an external light source (laser or LEDs)2. For animal applications, this method includes contact or noncontact placement of the LED or laser probe on the animal&#39;s head. Depending on the therapeutic region of interest, a light probe can be placed either over the entire head (for covering all the brain areas) or over a specific portion of the head, such as the prefrontal, frontal, or parietal region. The partial transmission of red/NIR light through the scalp, skull, and dura mater can reach the cortical surface level and provide an amount of photon energy sufficient to produce therapeutic benefits. Subsequently, the delivered light fluence at the cortical level would be propagated into the gray and white brain matter until it reaches the deeper structures of the brain3.
Light in the spectral bands at the red to far-red region (600-680 nm) and early NIR region (800-870 nm) corresponds to the absorption spectrum of cytochrome c oxidase, the terminal enzyme of the mitochondrial respiratory chain4. It is hypothesized that PBMT in the red/NIR spectrum causes photodissociation of nitric oxide (NO) from cytochrome c oxidase, resulting in increases in mitochondrial electron transport and, ultimately, increased ATP generation5. With respect to neuronal applications, the potential neurostimulatory benefits of brain PBMT using transcranial irradiation methods have been reported in a variety of preclinical studies, including rodent models of traumatic brain injury (TBI)6, acute stroke7, Alzheimer&#39;s disease (AD)8, Parkinson&#39;s disease (PD)9, depression10, and aging11.
Brain aging is considered a neuropsychological condition that negatively affects some cognitive functions, such as learning and memory12. Mitochondria are the primary organelles responsible for ATP production and neuronal bioenergetics. Mitochondrial dysfunction is known to be associated with age-related deficits in brain areas that are linked to spatial navigation memory, such as the hippocampus13. Because cranial treatment with red/NIR light primarily acts by modulation of mitochondrial bioenergetics, sufficient delivered light dosage to the hippocampus can result in the improvement of spatial memory outcomes14.
The aim of the current protocol is to demonstrate the transcranial PBMT procedure in mice, using low levels of red light. The required laser light transmission measurements through the head tissues of aged mice are described. Additionally, Barnes maze, as a hippocampus-dependent spatial learning and memory task, and hippocampal ATP levels, as a bioenergetics index, are used for an evaluation of the treatment impact in animals.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Ketamine</td>
			<td>Alfasan</td>
			<td>#1608234-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Alfasan</td>
			<td>#1608238-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>Sigma</td>
			<td>#A4679</td>
			<td></td>
		</tr>
		<tr>
			<td>Superglue</td>
			<td>Quickstar</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vibratome</td>
			<td>Campden Instruments</td>
			<td>#MA752-707</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical glass</td>
			<td>Sail Brand</td>
			<td>#7102</td>
			<td></td>
		</tr>
		<tr>
			<td>Power meter</td>
			<td>Thor labs</td>
			<td>#PM100D</td>
			<td></td>
		</tr>
		<tr>
			<td>Photodiode detector</td>
			<td>Thor labs</td>
			<td>#S121C</td>
			<td></td>
		</tr>
		<tr>
			<td>Caliper</td>
			<td>Pittsburgh</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>GaAlAs laser</td>
			<td>Thor Photomedicine</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Etho Vision</td>
			<td>Noldus</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Froilabo</td>
			<td>#SW14R</td>
			<td></td>
		</tr>
		<tr>
			<td>Earmuffs</td>
			<td>Blue Eagle</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Digital camera</td>
			<td>Visionlite</td>
			<td>#VCS2-E742H</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterio amplifier</td>
			<td>Sony</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Hamonteb</td>
			<td>#665.128321</td>
			<td></td>
		</tr>
		<tr>
			<td>Barnes maze</td>
			<td>Costom-made</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ATP assay kit</td>
			<td>Sigma</td>
			<td>#MAK190</td>
			<td></td>
		</tr>
		<tr>
			<td>Elisa reader</td>
			<td>Awareness</td>
			<td>#Stat Fax 2100</td>
			<td></td>
		</tr>
	</tbody>
</table>

a protocol for transcranial photobiomodulation therapy in mice

Transcranial photobiomodulation is a potential innovative noninvasive therapeutic approach for improving brain bioenergetics, brain function in a wide range of neurological and psychiatric disorders, and memory enhancement in age-related cognitive decline and neurodegenerative diseases. We describe a laboratory protocol for transcranial photobiomodulation therapy (PBMT) in mice. Aged BALB/c mice (18 months old) are treated with a 660 nm laser transcranially, once daily for 2 weeks. Laser transmittance data shows that approximately 1% of the incident red light on the scalp reaches a 1 mm depth from the cortical surface, penetrating the dorsal hippocampus. Treatment outcomes are assessed by two methods: a Barnes maze test, which is a hippocampus-dependent spatial learning and memory task evaluation, and measuring hippocampal ATP levels, which is used as a bioenergetics index. The results from the Barnes task show an enhancement of the spatial memory in laser-treated aged mice when compared with age-matched controls. Biochemical analysis after laser treatment indicates increased hippocampal ATP levels. We postulate that the enhancement of memory performance is potentially due to an improvement in hippocampal energy metabolism induced by the red laser treatment. The observations in mice could be extended to other animal models since this protocol could potentially be adapted to other species frequently used in translational neuroscience, such as rabbit, cat, dog, or monkey. Transcranial photobiomodulation is a safe and cost-effective modality which may be a promising therapeutic approach in age-related cognitive impairment.

Statistical analyses
The statistical analysis of data obtained from the Barnes training sessions was analyzed by two-way ANOVA; the other behavioral tests and analysis of hippocampal ATP levels among groups were carried out by one-way ANOVA, followed by Tukey&#39;s post hoc test. All data are expressed as means &#177; the standard error of the mean (SEM), except for the laser transmission data, which are shown a...

Watch this Scientific Journal Video about A Protocol for Transcranial Photobiomodulation Therapy in Mice at JoVE.com

A Protocol for Transcranial Photobiomodulation Therapy in Mice

Photobiomodulation therapy is an innovative noninvasive modality for the treatment of a wide range of neurological and psychiatric disorders and can also improve healthy brain function. This protocol includes a step-by-step guide to performing brain photobiomodulation in mice by transcranial light delivery, which can be adapted for use in other laboratory rodents.

Transcranial photobiomodulation is a potential innovative noninvasive therapeutic approach for improving brain bioenergetics, brain function in a wide ...

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Research

JoVE Journal

Neuroscience

12.0K Views.  Tabriz University of Medical Sciences. Photobiomodulation therapy is an innovative noninvasive modality for the treatment of a wide range of neurological and psychiatric disorders and can also improve healthy brain function. This protocol includes a step-by-step guide to performing brain photobiomodulation in mice by transcranial light delivery, which can be adapted for use in other laboratory rodents.

Video: A Protocol for Transcranial Photobiomodulation Therapy in Mice

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

There are many unanswered questions about cerebral lateralization. In particular, it remains unclear which aspects of language and nonverbal ability are lateralized, whether there are any disadvantages associated with atypical patterns of cerebral lateralization, and whether cerebral lateralization develops with age. In the past, researchers interested in these questions tended to use handedness as a proxy measure for cerebral lateralization, but this is unsatisfactory because handedness is only a weak and indirect indicator of laterality of cognitive functions1. Other methods, such as fMRI, are expensive for large-scale studies, and not always feasible with children2.
Here we will describe the use of functional transcranial Doppler ultrasound (fTCD) as a cost-effective, non-invasive and reliable method for assessing cerebral lateralization. The procedure involves measuring blood flow in the middle cerebral artery via an ultrasound probe placed just in front of the ear. Our work builds on work by Rune Aaslid, who co-introduced TCD in 1982, and Stefan Knecht, Michael Deppe and their colleagues at the University of M&uuml;nster, who pioneered the use of simultaneous measurements of left- and right middle cerebral artery blood flow, and devised a method of correcting for heart beat activity. This made it possible to see a clear increase in left-sided blood flow during language generation, with lateralization agreeing well with that obtained using other methods3.
The middle cerebral artery has a very wide vascular territory (see Figure 1) and the method does not provide useful information about localization within a hemisphere. Our experience suggests it is particularly sensitive to tasks that involve explicit or implicit speech production. The 'gold standard' task is a word generation task (e.g. think of as many words as you can that begin with the letter 'B') 4, but this is not suitable for young children and others with limited literacy skills. Compared with other brain imaging methods, fTCD is relatively unaffected by movement artefacts from speaking, and so we are able to get a reliable result from tasks that involve describing pictures aloud5,6. Accordingly, we have developed a child-friendly task that involves looking at video-clips that tell a story, and then describing what was seen.

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound fTCD

Functional transcranial Doppler sonography (fTCD) is a simple and non-invasive ultrasound technique which can be used to assess the lateralization of cognitive functions, especially language, and is suitable for use with children.

There are many unanswered questions about cerebral lateralization.  In particular, it remains unclear which aspects of language and nonverbal ability are ...

A Simple and Inexpensive Method for Determining Cold Sensitivity and Adaptation in Mice

Cold hypersensitivity is a serious clinical problem, affecting a broad subset of patients and causing significant decreases in quality of life. The cold plantar assay allows the objective and inexpensive assessment of cold sensitivity in mice, and can quantify both analgesia and hypersensitivity. Mice are acclimated on a glass plate, and a compressed dry ice pellet is held against the glass surface underneath the hindpaw. The latency to withdrawal from the cooling glass is used as a measure of cold sensitivity.
Cold sensation is also important for survival in regions with seasonal temperature shifts, and in order to maintain sensitivity animals must be able to adjust their thermal response thresholds to match the ambient temperature. The Cold Plantar Assay (CPA) also allows the study of adaptation to changes in ambient temperature by testing the cold sensitivity of mice at temperatures ranging from 30 &#176;C to 5 &#176;C. Mice are acclimated as described above, but the glass plate is cooled to the desired starting temperature using aluminum boxes (or aluminum foil packets) filled with hot water, wet ice, or dry ice. The temperature of the plate is measured at the center using a filament T-type thermocouple probe. Once the plate has reached the desired starting temperature, the animals are tested as described above.
This assay allows testing of mice at temperatures ranging from innocuous to noxious. The CPA yields unambiguous and consistent behavioral responses in uninjured mice and can be used to quantify both hypersensitivity and analgesia. This protocol describes how to use the CPA to measure cold hypersensitivity, analgesia, and adaptation in mice.

The Cold Plantar Assay (CPA) measures cold responsiveness between 30 &#176;C and 5 &#176;C, and can also measure cold adaptation. This protocol describes how to use the CPA to measure cold hypersensitivity, analgesia, and adaptation in mice.

Cold hypersensitivity is a serious clinical problem, affecting a broad subset of patients and causing significant decreases in quality of life.  The cold ...

Limbal Approach-Subretinal Injection of Viral Vectors for Gene Therapy in Mice Retinal Pigment Epithelium

The eye is a small and enclosed organ which makes it an ideal target for gene therapy. Recently various strategies have been applied to gene therapy in retinopathies using non-viral and viral gene delivery to the retina and retinal pigment epithelium (RPE). Subretinal injection is the best approach to deliver viral vectors directly to RPE cells. Before the clinical trial of a gene therapy, it is inevitable to validate the efficacy of the therapy in animal models of various retinopathies. Thus, subretinal injection in mice becomes a fundamental technique for an ocular gene therapy. In this protocol, we provide the easy and replicable technique for subretinal injection of viral vectors to experimental mice. This technique is modified from the intravitreal injection, which is widely used technique in ophthalmology clinics. The representative results of RPE/choroid/scleral complex flat-mount will help to understand the efficacy of this technique and adjust the volume and titer of viral vectors for the extent of gene transduction.

Subretinal injection is a surgical technique for effective gene delivery to retinal pigment epithelium in the mouse eye. Here we describe an easy and replicable method for subretinal injection of viral vectors to retinal pigment epithelium in experimental mice.

The eye is a small and enclosed organ which makes it an ideal target for gene therapy. Recently various strategies have been applied to gene therapy in ...

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a &#34;racecar&#34; version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p&#60;0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could&#160;affect behavioral task performance.

We describe an experimental procedure to quantify excitability and inhibition of primary motor cortex during a motor response inhibition task by using Transcranial Magnetic Stimulation throughout the course of a Stop Signal Task.

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) ...

The Combined Use of Transcranial Direct Current Stimulation and Robotic Therapy for the Upper Limb

Neurologic disorders such as stroke and cerebral palsy are leading causes of long-term disability and can lead to severe incapacity and restriction of daily activities due to lower and upper limb impairments. Intensive physical and occupational therapy are still considered main treatments, but new adjunct therapies to standard rehabilitation that may optimize functional outcomes are being studied.
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that polarizes underlying brain regions through the application of weak direct currents through electrodes on the scalp, modulating cortical excitability. Increased interest in this technique can be attributed to its low cost, ease of use, and effects on human neural plasticity. Recent research has been performed to determine the clinical potential of tDCS in diverse conditions such as depression, Parkinson&#39;s disease, and motor rehabilitation after stroke. tDCS helps enhance brain plasticity and seems to be a promising technique in rehabilitation programs.
A number of robotic devices have been developed to assist in the rehabilitation of upper limb function after stroke. The rehabilitation of motor deficits is often a long process requiring multidisciplinary approaches for a patient to achieve maximum independence. These devices do not intend to replace manual rehabilitation therapy; instead, they were designed as an additional tool to rehabilitation programs, allowing immediate perception of results and tracking of improvements, thus helping patients to stay motivated.
Both tDSC and robot-assisted therapy are promising add-ons to stroke rehabilitation and target the modulation of brain plasticity, with several reports describing their use to be associated with conventional therapy and the improvement of therapeutic outcomes. However, more recently, some small clinical trials have been developed that describe the associated use of tDCS and robot-assisted therapy in stroke rehabilitation. In this article, we describe the combined methods used in our institute for improving motor performance after stroke.

The combined use of transcranial direct current stimulation and robotic therapy as an add-on for conventional rehabilitation therapy may result in improved therapeutic outcomes due to modulation of brain plasticity. In this article, we describe the combined methods used in our institute for improving motor performance after stroke.

Neurologic disorders such as stroke and cerebral palsy are leading causes of long-term disability and can lead to severe incapacity and restriction of ...

Transcranial Direct Current Stimulation (tDCS) in Mice

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique proposed as an alternative or complementary treatment for several neuropsychiatric diseases. The biological effects of tDCS are not fully understood, which is in part explained due to the difficulty in obtaining human brain tissue. This protocol describes a tDCS mouse model that uses a chronically implanted electrode allowing the study of the long-lasting biological effects of tDCS. In this experimental model, tDCS changes the cortical gene expression and offers a prominent contribution to the understanding of the rationale for its therapeutic use.

Transcranial Direct Current Stimulation tDCS in Mice

Transcranial direct current stimulation (tDCS) is a therapeutic technique proposed to treat psychiatric diseases. An animal model is essential for understanding the specific biological alterations evoked by tDCS. This protocol describes a tDCS mouse model that uses a chronically implanted electrode.

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique proposed as an alternative or complementary treatment for ...

Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans and can be assessed using transcranial magnetic stimulation (TMS). Given the role of distal leg muscles in upright postural and dynamic tasks, such as walking, a growing research interest in the assessment and modulation of the corticospinal tracts relative to the function of these muscles has emerged in the last decade. However, methodological parameters used in previous work have varied across studies making the interpretation of results from cross-sectional and longitudinal studies less robust. Therefore, use of a standardized TMS protocol specific to the assessment of leg muscles&#39; corticomotor response (CMR) will allow for direct comparison of results across studies and cohorts. The objective of this paper is to present a protocol that provides the flexibility to simultaneously assess the bilateral CMR of two main ankle antagonistic muscles, the tibialis anterior and soleus, using single pulse TMS with a neuronavigation system. The present protocol is applicable while the examined muscle is either fully relaxed or isometrically contracted at a defined percentage of maximum isometric voluntary contraction. Using each subject&#39;s structural MRI with the neuronavigation system ensures accurate and precise positioning of the coil over the leg cortical representations during assessment. Given the inconsistency in CMR derived measures, this protocol also describes a standardized calculation of these measures using automated algorithms. Though this protocol is not conducted during upright postural or dynamic tasks, it&#160;can be used to assess bilaterally any pair of leg muscles, either antagonistic or synergistic, in both neurologically intact and impaired subjects.

The present protocol describes the simultaneous, bilateral assessment of the corticomotor response of the tibialis anterior and soleus during rest and tonic voluntary activation using a single pulse transcranial magnetic stimulation and neuronavigation system.

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans ...

Whole-Brain 3D Activation and Functional Connectivity Mapping in Mice using Transcranial Functional Ultrasound Imaging

Functional ultrasound (fUS) imaging is a novel brain imaging modality that relies on the high-sensitivity measure of the cerebral blood volume achieved by ultrafast doppler angiography. As brain perfusion is strongly linked to local neuronal activity, this technique allows the whole-brain 3D mapping of task-induced regional activation as well as resting-state functional connectivity, non-invasively, with unmatched spatio-temporal resolution and operational simplicity. In comparison with fMRI (functional magnetic resonance imaging), a main advantage of fUS imaging consists in enabling a complete compatibility with awake and behaving animal experiments. Moreover, fMRI brain mapping in mice, the most used preclinical model in Neuroscience, remains technically challenging due to the small size of the brain and the difficulty to maintain stable physiological conditions. Here we present a simple, reliable and robust protocol for whole-brain fUS imaging in anesthetized and awake mice using an off-the-shelf commercial fUS system with a motorized linear transducer, yielding significant cortical activation following sensory stimulation as well as reproducible 3D functional connectivity pattern for network identification.

This protocol describes the quantification of volumetric cerebral hemodynamic variations in the mouse brain using functional ultrasound (fUS). Procedures for 3D functional activation map following sensory stimulation as well as resting-state functional connectivity are provided as illustrative examples, in anesthetized and awake mice.

Functional ultrasound (fUS) imaging is a novel brain imaging modality that relies on the high-sensitivity measure of the cerebral blood volume achieved by ...

Establishing a Transcranial Middle Cerebral Artery Occlusion Mice Model

A Modified Transcranial Middle Cerebral Artery Occlusion Model to Study Stroke Outcomes in Aged Mice

In experimental stroke research, middle cerebral artery occlusion (MCAO) with an intraluminal filament is widely used to model ischemic stroke in mice. The filament MCAO model typically exhibits a massive cerebral infarction in C57Bl/6 mice that sometimes includes brain tissue in the territory supplied by the posterior cerebral artery, which is largely due to a high incidence of posterior communicating artery atresia. This phenomenon is considered a major contributor to the high mortality rate observed in C57Bl/6 mice during long-term stroke recovery after filament MCAO. Thus, many chronic stroke studies exploit distal MCAO models. However, these models usually produce infarction only in the cortex area, and consequently, the assessment of post-stroke neurologic deficits could be a challenge. This study has established a modified transcranial MCAO model in which the MCA at the trunk is partially occluded either permanently or transiently via a small cranial window. Since the occlusion location is relatively proximal to the origin of the MCA, this model generates brain damage in both the cortex and striatum. Extensive characterization of this model has demonstrated an excellent long-term survival rate, even in aged mice, as well as readily detectable neurologic deficits. Therefore, the MCAO mouse model described here represents a valuable tool for experimental stroke research.

Author Spotlight: Innovative Techniques and Future Directions in Stroke Research 

This protocol demonstrates a unique mouse stroke model with a medium-sized infarct and an excellent survival rate. This model allows preclinical stroke researchers to extend the ischemia duration, use aged mice, and assess long-term functional outcomes.

In experimental stroke research, middle cerebral artery occlusion (MCAO) with an intraluminal filament is widely used to model ischemic stroke in mice. ...

Treatment of Phantom Limb Pain by Remote Transcranial Direct Current Stimulation

Using Home-based, Remotely Supervised, Transcranial Direct Current Stimulation for Phantom Limb Pain

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses low-amplitude direct currents to alter cortical excitability. Previous trials have established the safety and tolerability of tDCS, and its potential to mitigate symptoms. However, the effects are cumulative, making it more difficult to have adherence to the treatment since frequent visits to the clinic or outpatient center are required. Moreover, the time needed for transportation to the center and the related expenses limit the accessibility of the treatment for many participants.
Following guidelines for remotely supervised transcranial direct current stimulation (RS-tDCS) implementation, we propose a protocol designed for remotely supervised and home-based participation that uses specific devices and materials modified for patient use, with real-time monitoring by researchers through an encrypted video conferencing platform. We have developed detailed instructional materials and structured training procedures to allow for self- or proxy-administration while supervised remotely in real time. This protocol has a specific design to have a series of checkpoints during training and execution of the visit. This protocol is currently in use in a large pragmatic study of RS-tDCS for phantom limb pain (PLP). In this article, we will discuss the operational challenges of conducting a home-based RS-tDCS session and show methods to enhance its efficacy with supervised sessions.

Author Spotlight: Insights into Remotely Supervised Neuromodulation Procedure for Phantom Limb Pain

The goal of this study is to describe a protocol for the home-based delivery of remotely supervised transcranial direct current stimulation (RS-tDCS) conserving the standard procedures of in-clinic practice, including safety, reproducibility, and tolerability. The participants included will be patients with phantom limb pain (PLP).

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses low-amplitude direct currents to alter cortical ...