Name: transcranial direct current stimulation (tdcs) in mice
Uploaded: 2018-09-23T15:00:00
Description: Watch this Scientific Journal Video about Transcranial Direct Current Stimulation tDCS in Mice at JoVE.com

We thank Mr. Rodrigo de Souza for assistance in maintaining mouse colonies. L.A.V.M is a CAPES postdoctoral fellow. This work was supported by the grant PRONEX (FAPEMIG: APQ-00476-14).

Individually-housed male adult (8-12 weeks) C57BL/6 mice were used in this experiment. Animals received proper care before, during and after experimental procedures with food and water ad libitum. All procedures were approved by the animal ethics committee from Federal University of Minas Gerais (protocol number 59/2014).
1. Electrode Placement
<ol>
	<li>Sedating and fixating the animal onto the stereotaxic apparatus
	<ol>
		<li>Sterilize all the necessary ...

<ol>
	<li>Filmer, H. L., Dux, P. E., Mattingley, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+transcranial+direct+current+stimulation+for+understanding+brain+function.">Applications of transcranial direct current stimulation for understanding brain function.</a> Trends in Neurosciences. 37 (12), 742-753 (2014).</li><li>Nitsche, M. A., Paulus, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sustained+excitability+elevations+induced+by+transcranial+DC+motor+cortex+stimulation+in+humans.">Sustained excitability elevations induced by transcranial DC motor cortex stimulation in humans.</a> Neurology. 57 (10), 1899-1901 (2001).</li><li>Kronberg, G., Bridi, M., Abel, T., Bikson, M., Parra, L. 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P., 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=Evidence-based+guidelines+on+the+therapeutic+use+of+transcranial+direct+current+stimulation+(tDCS).">Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS).</a> Clinical Neurophysiology. 128 (1), 56-92 (2017).</li><li>Monai, 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=Calcium+imaging+reveals+glial+involvement+in+transcranial+direct+current+stimulation-induced+plasticity+in+mouse+brain.">Calcium imaging reveals glial involvement in transcranial direct current stimulation-induced plasticity in mouse brain.</a> Nature Communications. 7, 11100 (2016).</li><li>Marquez-Ruiz, J., 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+direct-current+stimulation+modulates+synaptic+mechanisms+involved+in+associative+learning+in+behaving+rabbits.">Transcranial direct-current stimulation modulates synaptic mechanisms involved in associative learning in behaving rabbits.</a> Proc. 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S., 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=Prolonged+visual+memory+enhancement+after+direct+current+stimulation+in+Alzheimer's+disease.">Prolonged visual memory enhancement after direct current stimulation in Alzheimer's disease.</a> Brain Stimulation. 5 (3), 223-230 (2012).</li><li>Cosentino, G., 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=Anodal+tDCS+of+the+swallowing+motor+cortex+for+treatment+of+dysphagia+in+multiple+sclerosis:+a+pilot+open-label+study.">Anodal tDCS of the swallowing motor cortex for treatment of dysphagia in multiple sclerosis: a pilot open-label study.</a> Neurological Sciences. , 7-9 (2018).</li><li>Kaski, D., Dominguez, R. O., Allum, J. H., Islam, A. F., Bronstein, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combining+physical+training+with+transcranial+direct+current+stimulation+to+improve+gait+in+Parkinson's+disease:+A+pilot+randomized+controlled+study.">Combining physical training with transcranial direct current stimulation to improve gait in Parkinson's disease: A pilot randomized controlled study.</a> Clinical Rehabilitation. 28 (11), 1115-1124 (2014).</li><li>Monai, 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=Calcium+imaging+reveals+glial+involvement+in+transcranial+direct+current+stimulation-induced+plasticity+in+mouse+brain.">Calcium imaging reveals glial involvement in transcranial direct current stimulation-induced plasticity in mouse brain.</a> Nature Communications. 7, 11100 (2016).</li><li>Fritsch, B., 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=Direct+current+stimulation+promotes+BDNF-dependent+synaptic+plasticity:+potential+implications+for+motor+learning.">Direct current stimulation promotes BDNF-dependent synaptic plasticity: potential implications for motor learning.</a> Neuron. 66 (2), 198-204 (2010).</li><li>Winkler, 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=Sensory+and+Motor+Systems+Anodal+Transcranial+Direct+Current+Stimulation+Enhances+Survival+and+Integration+of+Dopaminergic+Cell+Transplants+in+a+Rat+Parkinson+Model.">Sensory and Motor Systems Anodal Transcranial Direct Current Stimulation Enhances Survival and Integration of Dopaminergic Cell Transplants in a Rat Parkinson Model.</a> New Research. 4 (5), 17-63 (2017).</li><li>Nasehi, M., Khani-Abyaneh, M., Ebrahimi-Ghiri, M., Zarrindast, M. 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In recent years, neurostimulation techniques have been entering clinical practice as a promising procedure to treat neuropsychiatric disorders23. To reduce the constraint imposed by the lack of knowledge of the mechanisms of neurostimulation, we presented here a tDCS mouse model carrying an electrode that can target brain regions. Since the electrode is chronically implantable, this animal model enables the investigation of long-lasting biological effects evoked by tDCS (for at least 1 month) in c...

Transcranial Direct Current Stimulation (tDCS) is a non-invasive, low-cost, therapeutic technique, which focuses on neuronal modulation through the use of low-intensity continuous currents1. There are currently two setups (anodal and cathodal) for tDCS. While the anodal stimulation exerts a current electric field too weak to trigger action potentials, electrophysiology studies have shown that this method produces changes in synaptic plasticity2. For example, evidence shows that tDCS induces long-term potentiation (LTP) effects such as increased peak amplitude of the excitatory postsynaptic potentials3,4 and modulation of cortical excitability5.
Conversely, cathodal stimulation induces inhibition, resulting in membrane hyperpolarization6. A hypothesis for this mechanism is based on the physiological findings where tDCS is described to modulate action potential frequency and duration in the neuronal body3. Notably, this effect does not directly evoke action potentials, though it can shift the depolarization threshold and facilitate or hamper neuronal firing7. These contrasting effects have been previously demonstrated. For example, anodal and cathodal stimulation produced opposing effects in conditioned responses registered via electromyography activity in rabbits8. However, studies have also shown that prolonged anodal stimulation sessions may decrease excitability while increasing cathodal currents may lead to excitability, presenting self-contrasting effects3.
Both anodal and cathodal stimuli aggregate the use of electrode pairs. For example, in anodal stimulation, the &#34;active&#34; or &#34;anode&#34; electrode is placed over the brain region to be modulated whereas the &#34;reference&#34; or &#34;cathode&#34; electrode is situated over a region where the effect of current is assumed to be insignificant9. In the cathodal stimulation, electrode disposition is inverted. The stimulation intensity for effective tDCS depends on the current intensity and electrode dimensions, which affect the electric field differently10. In most published studies, the average current intensity is between 0.10 to 2.0 mA and 0.1 mA to 0.8 mA for human and mice, respectively6,11. Although the electrode size of 35 cm2 is typically used in humans, there is no proper understanding regarding electrode dimensions for rodents and a more thorough investigation is needed6.
tDCS has been proposed in clinical studies with the attempt of offering an alternative or complementary treatment for several neurological and neuropsychiatric disorders11 such as epilepsy12, bipolar disorder13, stroke5, major depression14, Alzheimer&#39;s disease15, multiple sclerosis16 and Parkinson&#39;s disease17. Despite growing interest in tDCS and its use in clinical trials, detailed cellular and molecular evoked alterations in brain tissue, short and long-lasting effects, as well as behavioral outcomes, are yet to be more deeply investigated18,19. Since a direct human approach to thoroughly study tDCS is not viable, the use of a tDCS animal model may offer valuable insights into the cellular and molecular events underlying the therapeutic mechanisms of tDCS due to the accessibility to the animal&#39;s brain tissue.
Available evidence is limited regarding tDCS models in mice. Most of the reported models used different implanting layouts, electrode dimensions, and materials. For example, Winkler et al. (2017) implanted the head electrode (Ag/AgCl, 4 mm in diameter) filled with saline and fixed it to the cranium with acrylic cement and screws20. Different from our approach, their chest electrode was implanted (platinum, 20 x 1.5 mm). Nasehi et al. (2017) used a procedure very similar to ours, although the thoracic electrode was made from a saline-soaked sponge (carbon filled, 9.5 cm2)21. Another study implanted both electrodes into the animal&#39;s head, which was achieved by using fixed plates and covering the animal&#39;s head with a hydrogel conductor22. Here, we describe a tDCS mouse model that uses a chronically implanted electrode through simple surgical procedures and tDCS setup (Figure 1).

<table border="0" cellpadding="0" cellspacing="0" style="width:1152px;" width="1152">
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		<tr height="21">
			<td height="21" style="height:21px;width:457px;">BD Ultra-Fine 50U Syringe</td>
			<td style="width:175px;">BD</td>
			<td style="width:101px;">10033430026</td>
			<td style="width:419px;">For intraperitonially injection.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Shaver (Philips Multigroom)</td>
			<td>Philips (Brazil)</td>
			<td>QG3340/16</td>
			<td style="width:419px;">For surgical site trimming.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical Equipment</td>
			<td></td>
			<td></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Model 940 Small Animal Stereotaxic Instrument with Digital Display Console</td>
			<td>KOPF</td>
			<td>940</td>
			<td style="width:419px;">For animal surgical restriction and positioning.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Model 922 Non-Rupture 60 Degree Tip Ear Bars</td>
			<td>KOPF</td>
			<td>922</td>
			<td style="width:419px;">For animal surgical restriction and positioning.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cannula Holder</td>
			<td>KOPF</td>
			<td>1766-AP</td>
			<td style="width:419px;">For implant positioning.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Precision Stereo Zoom Binocular Microscope (III) on Boom Stand</td>
			<td>WPI</td>
			<td>PZMIII-BS</td>
			<td style="width:419px;">For bregma localization and implant positioning.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Temperature Control System Model&#160;</td>
			<td>KOPF</td>
			<td>TCAT-2LV</td>
			<td style="width:419px;">For animal thermal control.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cold Light Source&#160;</td>
			<td>WPI</td>
			<td>WA-12633</td>
			<td style="width:419px;">For focal brightness</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tabletop Laboratory Animal Anesthesia System with Scavenging</td>
			<td>VetEquip</td>
			<td>901820</td>
			<td style="width:419px;">For isoflurane delivery and safety.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">VaporGuard Activated Charcoal Adsorption Filter</td>
			<td>VetEquip</td>
			<td>931401</td>
			<td style="width:419px;">Delivery system safety measures.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Model 923-B Mouse Gas Anesthesia Head Holder</td>
			<td>KOPF</td>
			<td>923-B</td>
			<td style="width:419px;">For animal restriction and O2 and isoflurane delivery.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Oxygen regulator, E-cylinder&#160;</td>
			<td>VetEquip</td>
			<td>901305</td>
			<td style="width:419px;">For O2 regulation and delivery.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Oxygen hose &#8211; green&#160;</td>
			<td>VetEquip</td>
			<td>931503</td>
			<td style="width:419px;">For O2 and isoflurane delivery.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Infrared Sterilizer 800 &#186;C</td>
			<td>Marconi</td>
			<td>MA1201</td>
			<td style="width:419px;">For instrument sterilization.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical Instruments</td>
			<td></td>
			<td></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fine Scissors - ToughCut</td>
			<td>Fine Science Tools</td>
			<td>14058-11</td>
			<td style="width:419px;">For incision.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical Hooks</td>
			<td>INJEX</td>
			<td>1636</td>
			<td style="width:419px;">In House Fabricated - Used to clear the surgical site from skin and fur.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Standard Tweezers or Forceps</td>
			<td>-</td>
			<td>-</td>
			<td style="width:419px;">For skin grasping.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical Consumables</td>
			<td></td>
			<td></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vetbond</td>
			<td>3M</td>
			<td>SC-361931</td>
			<td style="width:419px;">For incision closing.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cement and Catalyzer KIT (Duralay)</td>
			<td>Reliance</td>
			<td>2OZ</td>
			<td style="width:419px;">For implant fixation.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sterile Cotton Swabs (Autoclaved)</td>
			<td>JnJ</td>
			<td>75U</td>
			<td style="width:419px;">For surgical site antisepsis.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">24 Well Plate (Tissue Culture Plate)</td>
			<td>SARSTEDT</td>
			<td>831,836</td>
			<td style="width:419px;">For cement preparation.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Application Brush</td>
			<td>parkell</td>
			<td>S286</td>
			<td style="width:419px;">For cement mixing and application.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pharmaceutics</td>
			<td></td>
			<td></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Xylazin (ANASEDAN 2%)</td>
			<td>Ceva Pharmaceutical (Brazil)</td>
			<td>P10160</td>
			<td style="width:419px;">For anesthesia induction.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ketamine (DOPALEN 10%)</td>
			<td>Ceva Pharmaceutical (Brazil)</td>
			<td>P30101</td>
			<td style="width:419px;">For anesthesia induction.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isoflurane (100%)</td>
			<td>Crist&#225;lia (Brazil)</td>
			<td>100ML</td>
			<td style="width:419px;">For anesthesia maintenance.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Lidocaine (XYLESTESIN 5%)</td>
			<td>Cristal Pharma</td>
			<td>-</td>
			<td style="width:419px;">For post-surgical care.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ketoprofen (PROFENID 100 mg)</td>
			<td>Sanofi Aventis</td>
			<td>20ML</td>
			<td style="width:419px;">For post-surgical care.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ringer&#39;s Lactate Solution</td>
			<td>SANOBIOL LAB</td>
			<td>############</td>
			<td style="width:419px;">For post-surgical care.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TobraDex (Dexamethasone 1 mg/g)</td>
			<td>Alcon</td>
			<td>631</td>
			<td style="width:419px;">For eye lubrification and protection.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stimulation</td>
			<td></td>
			<td></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Animal Transcranial Stimulator</td>
			<td>Soterix Medical</td>
			<td>2100</td>
			<td style="width:419px;">For current generation.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pin-type electrode Holder (Cylindrical Holder Base)</td>
			<td>Soterix Medical</td>
			<td>2100</td>
			<td style="width:419px;">Electrode support (Implant).</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pin-type electrode (Ag/AgCl)</td>
			<td>Soterix Medical</td>
			<td>2100</td>
			<td style="width:419px;">For current delivery (electrode).&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;">Pin-type electrode cap</td>
			<td>Soterix Medical</td>
			<td>2100</td>
			<td style="width:419px;">For implant protection.</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;">Body Electrode (Ag/AgCl Coated)</td>
			<td>Soterix Medical</td>
			<td>2100</td>
			<td style="width:419px;">For current delivery (electrode).&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Saline Solution (0.9%)</td>
			<td>FarmaX</td>
			<td>############</td>
			<td style="width:419px;">Conducting medium for current delivery.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Standard Tweezers or Forceps</td>
			<td>-</td>
			<td>-</td>
			<td style="width:419px;">For tDCS setup.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:457px;">Real Time Polymerase Chain Reaction</td>
			<td style="width:175px;"></td>
			<td style="width:101px;"></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:457px;">BioRad CFX96 Real Time System</td>
			<td style="width:175px;">BioRad</td>
			<td style="width:101px;">C1000</td>
			<td style="width:419px;">For qPCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SsoAdvancedTM Universal SYBR Green Supermix (5 X 1mL)</td>
			<td style="width:175px;">BioRad</td>
			<td>1725271</td>
			<td style="width:419px;">For qPCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hard Shell PCR Plates PCT COM 50 p/ CFX96</td>
			<td>BioRad</td>
			<td>HSP9601</td>
			<td style="width:419px;">For qPCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microseal &#34;B&#34; seal pct c/ 100</td>
			<td>BioRad</td>
			<td>MSB1001</td>
			<td style="width:419px;">For qPCR</td>
		</tr>
	</tbody>
</table>

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.

The surgical protocol presented long-term implant stability for at least one month, with no inflammatory signals at the stimulated site nor any other undesired effect. All the animals survived the surgical procedure and tDCS sessions (n = 8). In this experiment, tDCS implants were positioned over the M1 and M2 cortices (+1.0 mm anterior-posterior and 0.0 mm lateral to bregma). One week later, tDCS (n = 3-4) and sham (n = 3) mice were stimulated for five consecutive days during 10 min at 0...

Watch this Scientific Journal Video about Transcranial Direct Current Stimulation tDCS in Mice at JoVE.com

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) in Mice

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

The Alvar Gaaud Procedure is to apply transcranial direct current stimulation in mice. This achieved by generating low intense currents from a direct current generator, and sending it down directly to the animal through electrodes. tDCS has been investigated as a non-drug therapeutical alternative for main psychiatric disorders in humans, such as depression, schizophrenia, Alzheimer disease, AHDH, and autism.Moreover, tDCS is a unique technique due to its low cost, ease of use, and non-invasive profile. However, the biological effects of tDCS are not entirely understood, and there is no consensus regarding stimulation parameters, such as current intensity, duration, and tile of brain areas. Therefor, the use of minimum orders is essential for a thorough study of such mechanisms, which will lead to a better understanding of the clinical efficacy of tDCS through the acquisition and analysis of behavior cellular and molecular data.There are currently two electrode setups for tDCS, referred as anodal and cathodal stimulation. In the anodal stimulation, currents are delivered directly to the animal's head, through the animal's body, and into the cathode positioned on the animal's thorax. While in the cathodal stimulation the current enters through the animal's thorax, travels up to its head and into the cathode.In both situations a current generator controls the current intensity and stimulation duration. While producing a contact quality and inferring feedback. There are many different setups for active positioning.Therefor, all three dimensional axis should be taken into consideration. In this protocol a head electrode was implanted one millimeter into rooted bregma, onto the side to middle line of the skull, and the body electrode was positioned onto the animal's chest. Due to a short period simulation, it was recommended to use a fast action and short term anesthesia, such as vaporized isoflurane.This procedure is comprised of two critical steps. Electrode placement and transcranial direct current stimulation. Surgical instruments were sterilized with pre-maintenance at 440 degrees Celsius.Cotton swabs were autoclaved at 20 pounds per square inch at 121 degrees Celsius for 20 minutes. Turn the thermal platform controller to 37 degrees Celsius. Weigh the animal, and calculate the appropriate dose for anesthesia induction.Use a mixture of ketamine and xylazine at a dose of 100 milligrams per kilogram of ketamine, and 8 milligrams per kilogram of xylazine. Needle size 31G. The animal should fall asleep within 2 to 3 minutes.Use an electrical shaver or razor to shave down the surgical site. Place the animal onto the stereotaxic apparatus over the pre-warmed heating plate. Hold the animal's head and insert the tip ear bars into each of the animal's ears, to fix it to the sterotaxic platform.Verify there is no lateral head shifting, and little vertical movement by slowly shifting the animal's head. Gently slide the anesthesia mask over the mouse's nose and fix in place by tightening the screw. Apply eye ointment to the animal's eyes to prevent corneal drying during the surgery.Use a cotton swab to prepare the surgical site with three alternating scrubs of povidone iodine, or 2%chlorohexidine and 70%ethinol. Use a pair of tweezers to verify anesthesia adopt by lightly squeezing the animal's toes, and verifying the laws of animal pedo-withdrawal general pinch reflex. Make an incision about three millimeters posterior to the animal's ear line, and stop in the eye line.The incision site must have approximately one centimeter in length to be large enough to receive the implant. Gently scrape the cranium with a bone scraper to improve glue and cement adherence. This must be done light handed with intention of creating micro-scratches.Carefully position surgical hooks to the loose skin to maintain an open surgical field and free it of obstructions, such as skin an fur. Use a sterile cotton swab to gently dry the animal's scalp. Use a dissection microscope to visualize the top of the animal's cranium.Attach a needle to the sterotaxic holder and locate the bregma. Position the needle directly above the animal's head is lightly touching the bregma. Use the bregma as a reference to adjust the coordinates of the area of interest.Fix the implant on the stereotaxic holder. Position the implant over the animal's head and lower it slowly onto the region of interest. Use a needle to spread one drop, approximately 35 microliters, of superglue onto the implant space.Slowly move the holder downwards until it touches the skull. Be sure the implant space is entirely in contact with the surface. Prepare the surgical cement according to the manufacturer's instructions.After precise positioning, apply three thin, even layers of cement across the cranium, and onto the lower portion of the implant. Apply drop per drop by using an application brush. Layers must form U-shaped structure for further structural support of the implant.Leave the implant's screw thread clean of cement to allow a smooth, unobstructed connection. Allow each layer to dry for approximately four minutes. After drying, carefully remove the holder until it is completely detached from the implant.Always use extreme caution when handling the implant, since it might be accidentally destructed from the animal's skull. Hydrate the animal's skin and incision site with a saline soaked cotton swab. Cut the skin over the base of the implant.Use a pair of tweezers to bring the tissue together, and close the incision with one drop of tissue surgical glue per point 2 centimeters of tissue. Infiltrate 1 to 2%lidocaine in the incision site and underlying tissues. Hydrate the animal with 500 microliters of lactate ringer simultaneously.Place the mouse into a pre-warmed 37 degree Celsius clean single house cage. Build a small dish of wet food pellets in the cage, for easy access to food in the following hours. Register the animal's post surgical weight.The animal must be administered with ketoprofen. 5 milligrams per kilogram simultaneously after the surgery and over the next two days. Make sure that tDCS stimulator is fully charged.Attach the anode and cathode cables to the tDCS stimulator and make them available near the simulation site. Attach the pin-type electrode to the sterotaxic holder. Set the thermal platform to 37 degrees Celsius.Turn on the oxygen flowmeter on the inhalation anesthesia system to 1 Liter per minute. Place the mouse into the anesthesia induction chamber. Turn on the isoflurane vaporizer to 3%Allow the animal to undergo isoflurane effects for four minutes.While the animal is in the induction chamber, use a sterile syringe to fill the body electrode with 0.9%saline solution. Remove the animal from the induction chamber and position its chest over the body electrode. Gently slide the anesthesia mask over the mouse's nose and fix in place.Lower the isoflurane output to 1.5%Fill the implant and the pin-type electrode with saline. Carefully attach them together. Adjust the stimulation time and current intensity according to your protocol.Verify the contact quality on the tDCS system later. Start the stimulation. Observe the current ramping up for 20 seconds to the selected value.And maintaining itself stead for the established time. Then, at the end of the section ramping down again. Activate the shin button for controlise.Observe the current ramping up for 20 seconds to the selected value. And then down one for the rest of the stimulation period, with a final ramp to the selected value, at the end, with a consecutive ramped down. One the stimulation section is complete, carefully transfer the animal to a pre-warmed 37 degree Celsius cage for 10 minutes.This protocol uses tDCS to stimulate the mouse's cerebral cortex one millimeter anterior to the bregma. This graph shows the statisticalized and gene expression after tDCS stimulation protocol. Using a 0.35 milliamperes current intensity for 10 minutes per day.The tCDS implant presented self viable from day one through five with no significant difference among the days in contact quality. There are a variety of tCDS stimulation protocols in model brains. Protocols must be chosen according to the particularities of your experiment is basing itself on.Area of stimulation, current intensity, session duration, and electrode positioning. In this particular protocol, we aimed at modulating the motor cortex through our known tDCS with the current of 350 microamperes for 10 minutes. After watching this video you will be able to perform tDCS in mice.When someone practices surgery may take up to four minutes per animal. It is essential to take into consideration the animal care guidelines when utilizing the mice during the operation and following the post-surgical care to the animals so that the animals stay healthy during the study. We also recommend waiting five to seven days after implant placement to perform the experiments, since the animal's physiological response to trauma may interfere with the biological outcomes.

transcranial-direct-current-stimulation-tdcs-in-mice

Research

JoVE Journal

Neuroscience

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful rest."1,2,3 It is thought the default mode network corresponds to self-referential or "internal mentation".2,3
It has been hypothesized that, in humans, activity within the default mode network is correlated with certain pathologies (for instance, hyper-activation has been linked to schizophrenia 4,5,6 and autism spectrum disorders 7 whilst hypo-activation of the network has been linked to Alzheimer's and other neurodegenerative diseases 8). As such, noninvasive modulation of this network may represent a potential therapeutic intervention for a number of neurological and psychiatric pathologies linked to abnormal network activation. One possible tool to effect this modulation is Transcranial Magnetic Stimulation: a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses.9
In order to explore the default mode network's propensity towards and tolerance of modulation, we will be combining TMS (to the left inferior parietal lobe) with functional magnetic resonance imaging (fMRI). Through this article, we will examine the protocol and considerations necessary to successfully combine these two neuroscientific tools.

In this article, we examine the methodology and considerations relevant to the combination of TMS and fMRI to examine the effects of brain stimulation on the default network.

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful ...

Electrode Positioning and Montage in Transcranial Direct Current Stimulation

Transcranial direct current stimulation (tDCS) is a technique that has been intensively investigated in the past decade as this method offers a non-invasive and safe alternative to change cortical excitability2. The effects of one session of tDCS can last for several minutes, and its effects depend on polarity of stimulation, such as that cathodal stimulation induces a decrease in cortical excitability, and anodal stimulation induces an increase in cortical excitability that may last beyond the duration of stimulation6. These effects have been explored in cognitive neuroscience and also clinically in a variety of neuropsychiatric disorders &#x2013; especially when applied over several consecutive sessions4. One area that has been attracting attention of neuroscientists and clinicians is the use of tDCS for modulation of pain-related neural networks3,5. Modulation of two main cortical areas in pain research has been explored: primary motor cortex and dorsolateral prefrontal cortex7. Due to the critical role of electrode montage, in this article, we show different alternatives for electrode placement for tDCS clinical trials on pain; discussing advantages and disadvantages of each method of stimulation.

Transcranial direct current stimulation (tDCS) is an established technique to modulate cortical excitability1,2. It has been used as an investigative tool in neuroscience due to its effects on cortical plasticity, easy operation, and safe profile. One area that tDCS has been showing encouraging results is pain alleviation 3-5.

Transcranial direct current stimulation (tDCS) is a technique that has been intensively investigated in the past decade as this method offers a ...

Direct-current Stimulation and Multi-electrode Array Recording of Seizure-like Activity in Mice Brain Slice Preparation

Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the stimulation parameters (e.g., orientation, field strength, and stimulation duration) need to be examined in mice brain slice preparations. Testing and arranging the orientation of the electrode relative to the position of the mice brain slice are feasible. The present method preserves the thalamocingulate pathway to evaluate the effect of DCS on anterior cingulate cortex seizure-like activities. The results of the multichannel array recordings indicated that cathodal DCS significantly decreased the amplitude of the stimulation-evoked responses and duration of 4-aminopyridine and bicuculline-induced seizure-like activity. This study also found that cathodal DCS applications at 15 min caused long-term depression in the thalamocingulate pathway. The present study investigates the effects of DCS on thalamocingulate synaptic plasticity and acute seizure-like activities. The current procedure can test the optimal stimulation parameters including orientation, field strength, and stimulation duration in an in vitro mouse model. Also, the method can evaluate the effects of DCS on cortical seizure-like activities at both the cellular and network levels.

Studies have shown that cathodal transcranial direct-current stimulation can produce suppressive effects on drug-resistant seizures. In this study, an in vitro experimental setup was devised in which the direct-current stimulation and multielectrode array recording of seizure-like activity were evaluated in mice brain slice preparation. The direct-current stimulation parameters were evaluated.

Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Remotely Supervised Transcranial Direct Current Stimulation: An Update on Safety and Tolerability

The remotely supervised tDCS (RS-tDCS) protocol enables participation from home through guided and monitored self-administration of tDCS treatment while maintaining clinical standards. The current consensus regarding the efficacy of tDCS is that multiple treatment sessions are needed to observe targeted behavioral reductions in symptom burden. However, the requirement for patients to travel to clinic daily for stimulation sessions presents a major obstacle for potential participants, due to work or family obligations or limited ability to travel. This study presents a protocol that directly overcomes these obstacles by eliminating the need to travel to clinic for daily sessions.
This is an updated protocol for remotely supervised self-administration of tDCS for daily treatment sessions paired with a program of computer-based cognitive training for use in clinical trials. Participants only need to attend clinic twice, for a baseline and study-end visit. At baseline, participants are trained and provided with a study stimulation device, and a small laptop computer. Participants then complete the remainder of their stimulation sessions at home while they are monitored via videoconferencing software.
Participants complete computerized cognitive remediation during stimulation sessions, which may serve a therapeutic role or as a &#34;placeholder&#34; for other computer-based activity. Computers are enabled for real-time monitoring and remote control by study staff.
Outcome measures that assess feasibility and tolerance are administered remotely with the aid of visual analogue scales that are presented onscreen. Following completion of all RS-tDCS sessions, participants return to clinic for a study end visit in which all study equipment is returned.
Results support the safety, feasibility, and scalability of the RS-tDCS protocol for use in clinical trials. Across 46 patients, 748 RS-tDCS sessions have been completed. This protocol serves as a model for use in future clinical trials involving tDCS.

This manuscript provides an updated remote supervision protocol that enables participation in transcranial direct current stimulation (tDCS) clinical trials while receiving treatment sessions from home. The protocol has been successfully piloted in both patients with multiple sclerosis and Parkinson&#39;s disease.

The remotely supervised tDCS (RS-tDCS) protocol enables participation from home through guided and monitored self-administration of tDCS treatment while ...

Transcranial Electrical Brain Stimulation in Alert Rodents

Transcranial electrical brain stimulation can modulate cortical excitability and plasticity in humans and rodents. The most common form of stimulation in humans is transcranial direct current stimulation (tDCS). Less frequently, transcranial alternating current stimulation (tACS) or transcranial random noise stimulation (tRNS), a specific form of tACS using an electrical current applied randomly within a pre-defined frequency range, is used. The increase of noninvasive electrical brain stimulation research in humans, both for experimental and clinical purposes, has yielded an increased need for basic, mechanistic, safety studies in animals. This article describes a model for transcranial electrical brain stimulation (tES) through the intact skull targeting the motor system in alert rodents. The protocol provides step-by-step instructions for the surgical set-up of a permanent epicranial electrode socket combined with an implanted counter electrode on the chest. By placing a stimulation electrode into the epicranial socket, different electrical stimulation types, comparable to tDCS, tACS, and tRNS in humans, can be delivered. Moreover, the practical steps for tES in alert rodents are introduced. The applied current density, stimulation duration, and stimulation type may be chosen depending on the experimental needs. The caveats, advantages, and disadvantages of this set-up are discussed, as well as safety and tolerability aspects.

This protocol describes a surgical set-up for a permanent epicranial electrode socket and an implanted chest electrode in rodents. By placing a second electrode into the socket, different types of transcranial electrical brain stimulation can be delivered to the motor system in alert animals through the intact skull.

Transcranial electrical brain stimulation can modulate cortical excitability and plasticity in humans and rodents. The most common form of stimulation in ...

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 ...

Stimulation Location Determination using a 3D Digitizer with High-Definition Transcranial Direct Current Stimulation

The abundance of neuroimaging data and rapid development of machine learning has made it possible to investigate brain activation patterns. However, causal evidence of brain area activation leading to a behavior is often left missing. Transcranial direct current stimulation (tDCS), which can temporarily alter brain cortical excitability and activity, is a noninvasive neurophysiological tool used to study causal relationships in the human brain. High-definition transcranial direct current stimulation (HD-tDCS) is a noninvasive brain stimulation (NIBS) technique that produces a more focal current compared to conventional tDCS. Traditionally, the stimulation location has been roughly determined through the 10-20 EEG system, because determining precise stimulation points can be difficult. This protocol uses a 3D digitizer with HD-tDCS to increase accuracy in determination of stimulation points. The method is demonstrated using a 3D digitizer for more accurate localization of stimulation points in the right temporo-parietal junction (rTPJ).

Presented here is a protocol to achieve higher accuracy in determination of stimulation location combining a 3D digitizer with high-definition transcranial direct current stimulation.

The abundance of neuroimaging data and rapid development of machine learning has made it possible to investigate brain activation patterns. However, ...

In Vivo Intracellular Recording of Type-Identified Rat Spinal Motoneurons During Trans-Spinal Direct Current Stimulation

Intracellular recording of spinal motoneurons in vivo provides a &#8220;gold standard&#8221; for determining the cells&#8217; electrophysiological characteristics in the intact spinal network and holds significant advantages relative to classical in vitro or extracellular recording techniques. An advantage of in vivo intracellular recordings is that this method can be performed on adult animals with a fully mature nervous system, and therefore many observed physiological mechanisms can be translated to practical applications. In this methodological paper, we describe this procedure combined with externally applied constant current stimulation, which mimics polarization processes occurring within spinal neuronal networks. Trans-spinal direct current stimulation (tsDCS) is an innovative method increasingly used as a neuromodulatory intervention in rehabilitation after various neurological injuries as well as in sports. The influence of tsDCS on the nervous system remains poorly understood and the physiological mechanisms behind its actions are largely unknown. The application of the tsDCS simultaneously with intracellular recordings enables us to directly observe changes of motoneuron membrane properties and characteristics of rhythmic firing in response to the polarization of the spinal neuronal network, which is crucial for the understanding of tsDCS actions. Moreover, when the presented protocol includes the identification of the motoneuron with respect to an innervated muscle and its function (flexor versus extensor) as well as the physiological type (fast versus slow) it provides an opportunity to selectively investigate the influence of tsDCS on identified components of spinal circuitry, which seem to be differently affected by polarization. The presented procedure focuses on surgical preparation for intracellular recordings and stimulation with an emphasis on the steps which are necessary to achieve preparation stability and reproducibility of results. The details of the methodology of the anodal or cathodal tsDCS application are discussed while paying attention to practical and safety issues.

This protocol describes in vivo intracellular recording of rat lumbar motoneurons with simultaneous trans-spinal direct current stimulation. The method enables us to measure membrane properties and to record rhythmic firing of motoneurons before, during and after anodal or cathodal polarization of the spinal cord.

Intracellular recording of spinal motoneurons in vivo provides a &#8220;gold standard&#8221; for determining the cells&#8217; electrophysiological ...

Simultaneous Application of Transcranial Direct Current Stimulation during Virtual Reality Exposure

Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation that changes the likelihood of neuronal firing through modulation of neural resting membranes. Compared to other techniques, tDCS is relatively safe, cost-effective, and can be administered while individuals are engaged in controlled, specific cognitive processes. This latter point is important as tDCS may predominantly affect intrinsically active neural regions. In an effort to test tDCS as a potential treatment for psychiatric illness, the protocol described here outlines a novel procedure that allows the simultaneous application of tDCS during exposure to trauma-related cues using virtual reality (tDCS+VR) for veterans with posttraumatic stress disorder (NCT03372460). In this double-blind protocol, participants are assigned to either receive 2 mA tDCS, or sham stimulation, for 25 minutes while passively watching three 8-minute standardized virtual reality drives through Iraq or Afghanistan, with virtual reality events increasing in intensity during each drive. Participants undergo six sessions of tDCS+VR over the course of 2-3 weeks, and psychophysiology (skin conductance reactivity) is measured throughout each session. This allows testing for within and between session changes in hyperarousal to virtual reality events and adjunctive effects of tDCS. Stimulation is delivered through a built-in rechargeable battery-driven tDCS device using a 1 (anode) x 1 (cathode) unilateral electrode set-up. Each electrode is placed in a 3 x 3 cm (current density 2.22 A/m2) reusable sponge pocket saturated with 0.9% normal saline. Sponges with electrodes are attached to the participant&#8217;s skull using a rubber headband with the electrodes placed such that they target regions within the ventromedial prefrontal cortex. The virtual reality headset is placed over the tDCS montage in such a way as to avoid electrode interference.

This manuscript outlines a novel protocol to allow the simultaneous application of transcranial direct current stimulation during exposure to warzone trauma-related cues using virtual reality for veterans with posttraumatic stress disorder.