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. C. <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+Modulates+LTP+and+LTD:+Activity+Dependence+and+Dendritic+Effects.">Direct Current Stimulation Modulates LTP and LTD: Activity Dependence and Dendritic Effects.</a> Brain Stimulation. 10 (1), 51-58 (2017).</li><li>Pelletier, S. J., Cicchetti, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+and+Molecular+Mechanisms+of+Action+of+Transcranial+Direct+Current+Stimulation:+Evidence+from+In+Vitro+and+In+Vivo+Models.">Cellular and Molecular Mechanisms of Action of Transcranial Direct Current Stimulation: Evidence from In Vitro and In Vivo Models.</a> International Journal of Neuropsychopharmacology. 18 (2), pyu047 (2015).</li><li>Chang, M. C., Kim, D. Y., Park, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancement+of+cortical+excitability+and+lower+limb+motor+function+in+patients+with+stroke+by+transcranial+direct+current+stimulation.">Enhancement of cortical excitability and lower limb motor function in patients with stroke by transcranial direct current stimulation.</a> Brain Stimulation. 8 (3), 561-566 (2015).</li><li>Lefaucheur, J. 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. Natl. Acad. Sci. 109, 6710-6715 (2012).</li><li>Jackson, M. 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=Animal+models+of+transcranial+direct+current+stimulation:+Methods+and+mechanisms.">Animal models of transcranial direct current stimulation: Methods and mechanisms.</a> Clinical Neurophysiology. 127 (11), 3425-3454 (2016).</li><li>Cambiaghi, 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=Brain+transcranial+direct+current+stimulation+modulates+motor+excitability+in+mice.">Brain transcranial direct current stimulation modulates motor excitability in mice.</a> The European journal of neuroscience. 31 (4), 704-709 (2010).</li><li>Monte-Silva, K., 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=Induction+of+late+LTP-like+plasticity+in+the+human+motor+cortex+by+repeated+non-invasive+brain+stimulation.">Induction of late LTP-like plasticity in the human motor cortex by repeated non-invasive brain stimulation.</a> Brain Stimulation. 6 (3), 424-432 (2013).</li><li>San-Juan, D., 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+in+Mesial+Temporal+Lobe+Epilepsy+and+Hippocampal+Sclerosis.">Transcranial Direct Current Stimulation in Mesial Temporal Lobe Epilepsy and Hippocampal Sclerosis.</a> Brain Stimulation. 10 (1), 28-35 (2017).</li><li>Brunoni, A. R., 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+(tDCS)+in+unipolar+vs.+bipolar+depressive+disorder.">Transcranial direct current stimulation (tDCS) in unipolar vs. bipolar depressive disorder.</a> Progress in Neuro-Psychopharmacology and Biological Psychiatry. 35 (1), 96-101 (2011).</li><li>Brunoni, A. R., 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=Trial+of+Electrical+Direct-Current+Therapy+versus+Escitalopram+for+Depression.">Trial of Electrical Direct-Current Therapy versus Escitalopram for Depression.</a> New England Journal of Medicine. 376 (26), 2523-2533 (2017).</li><li>Boggio, P. 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. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+left+frontal+transcranial+direct-current+stimulation+on+propranolol-induced+fear+memory+acquisition+and+consolidation+deficits.">The effect of left frontal transcranial direct-current stimulation on propranolol-induced fear memory acquisition and consolidation deficits.</a> Behavioural Brain Research. 331 (May), 76-83 (2017).</li><li>Souza, 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=Neurobiological+mechanisms+of+antiallodynic+effect+of+transcranial+direct+current+stimulation+(tDCS)+in+a+mice+model+of+neuropathic+pain.">Neurobiological mechanisms of antiallodynic effect of transcranial direct current stimulation (tDCS) in a mice model of neuropathic pain.</a> Brain Research. 1682 (14-23), (2018).</li><li>Woods, A. 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=A+technical+guide+to+tDCS,+and+related+non-invasive+brain+stimulation+tools.">A technical guide to tDCS, and related non-invasive brain stimulation tools.</a> Clinical Neurophysiology. 127 (2), 1031-1048 (2016).</li><li>Cogan, S. 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=Tissue+damage+thresholds+during+therapeutic+electrical+stimulation.">Tissue damage thresholds during therapeutic electrical stimulation.</a> Journal of Neural Engineering. 13, 2 (2017).</li><li>Podda, M. V., 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+transcranial+direct+current+stimulation+boosts+synaptic+plasticity+and+memory+in+mice+via+epigenetic+regulation+of+Bdnf+expression.">Anodal transcranial direct current stimulation boosts synaptic plasticity and memory in mice via epigenetic regulation of Bdnf expression.</a> Scientific reports. 6 (October 2015), 22180 (2015).</li></ol>

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">
	<tbody>
		<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

13.7K visualizações.  Universidade Federal de Minas Gerais. O Procedimento Alvar Gaaud é aplicar estimulação de corrente direta transcraniana em camundongos. Isso foi conseguido gerando correntes intensas baixas a partir de um gerador de corrente direta, e enviando-o diretamente para o animal através de eletrodos. O TDCS tem sido investigado como uma alternativa terapêutica não medicamentosa para os principais transtornos psiquiátricos em humanos, como depressão, esquizofrenia, doença de Alzheimer, AHDH e autismo.Além disso, o TDCS é...