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.
la stimulation directe du courant transcrânienne cathodique (STCC) induit des effets suppresseurs sur les saisies résistantes aux médicaments. Pour effectuer des actions efficaces, les paramètres de stimulation (par exemple, l' orientation, l' intensité du champ, et la durée de stimulation) doivent être examinés dans les préparations de tranche des souris du cerveau. Agencer les essais et l'orientation de l'électrode par rapport à la position de la tranche de cerveau des souris sont possibles. La présente méthode permet de conserver la voie thalamocingulate pour évaluer l'effet du DCS sur les activités de saisie comme cortex cingulaire antérieur. Les résultats des enregistrements de matrice à canaux multiples indiquent que DCS cathodique diminué de manière significative l'amplitude de la réponse de stimulation évoquée et la durée de la 4-aminopyridine et l'activité épileptique analogue induite par la bicuculline. Cette étude a également révélé que les applications DCS cathodiques à 15 min causé la dépression à long terme dans la voie thalamocingulate. La présente étude examine les effets de DCS sur thalamocingulate plasticité synaptique et les activités de saisie comme aiguë. La procédure actuelle permet de tester les paramètres de stimulation optimale dont l' orientation, l' intensité du champ et de la durée de stimulation dans un modèle in vitro de la souris. En outre, la méthode peut évaluer les effets de DCS sur les activités de saisie comme corticales aux niveaux cellulaires et réseau.
Epilepsy is a common neurological disorder. Thirty percent of patients with epilepsy suffer from drug-resistant seizures1. Transcranial direct-current stimulation (tDCS) provides a noninvasive approach to control or alter network activities across large brain areas, such as seizures. Clinical studies have shown that tDCS effectively treats intractable seizures2 and can produce both short- and long-term suppressive effects on seizures3-5. However, the therapeutic mechanism of tDCS actions is still unclear. The brain slice model presented is an in vitro method to investigate how the therapeutic mechanism of tDCS actions alters the symptoms of seizure-like brain activities. Accordingly, to achieve its optimal effects, specific stimulation parameters including orientation, field strength, and stimulation duration need to be tested in an experimental model. Previous studies have shown that the orientation of the electric field is important to obtain therapeutic effects6. Thus, testing and arranging the orientation of electrodes relative to the position of the tested brain slice are feasible.
Frontal lobe epilepsy and anterior cingulate cortex (ACC) seizures are often drug-resistant7,8. Some studies have reported the application of tDCS in the cingulate cortex9-11. tDCS is shown to affect vigilance, decision making and emotion through alteration of ACC activities, and can modulate neuronal excitability and seizure activity in this brain region12. Therefore, suppressive effects of tDCS on ACC seizures might be helpful for clinical treatment and the evaluation of alternative treatments.
The present protocol describes the preparation of an electrode in the recording chamber for DCS of a brain slice and its effect on seizure-like activity recording with a multielectrode array (MEA).
Dans la présente étude, les effets de la durée et de l'orientation du DCS sur l'activité de saisie de type ACC ont été testés. Pour obtenir des données stables dans des tranches de cerveau de souris, comment garder l'intégrité de la voie MT-ACC et pour éviter tout dommage, il est essentiel, en particulier les étapes dans lesquelles deux coupes ventrales angle et une coupe dorsale du cortex sont faites. De plus, le temps de préparer la tranche de cerveau peut également affecter l'activité d…
The authors have nothing to disclose.
We are grateful for the technical support from the Neural Circuit Electrophysiology Core at Academia Sinica. This work was supported by the National Science Council (102-2320-B-001-026-MY3 and 100-2311-B-001-003-MY3) and Neuroscience Program of Academia Sinica.
Anesthetic: | |||
Isoflurane | Halocarbon Products Corporation | NDC 12164-002-25 | 4% |
Name | Company | Catalog Number | Comments |
aCSF (total:1L): | |||
D(+)-Glucose | MERCK | 1.08337.1000 | 10 mM |
Sodium hydrogen carbonate | MERCK | 1.06329.0500 | 25 mM |
Sodium chloride | MERCK | 1.06404.1000 | 124 mM |
(+)-Sodium L-ascorbate, >=98% | SIGMA | A4034-100G | 0.15 g / 2 c.c |
Magnesium sulfate, anhydrous,ReagentPlus | SIGMA | M7506-500G | 2 mM |
Calcium chloride dihydrate | MERCK | 1.02382.1000 | 2 mM |
Sodium dihydrogen phosphate monohydrate | MERCK | 1.06346.1000 | 1 mM |
Potassium chloride | May & Baker LTD Dagenham England | MS 7616 | 4.4 mM |
Name | Company | Catalog Number | Comments |
Drugs: | |||
(+)-Bicuculline | TOCRIS | 0130 | 5 µM in aCSF |
4-Aminopyridine | TOCRIS | 0940 | 250 µM in aCSF |
Name | Company | Catalog Number | Comments |
Brain slice Preparation: | |||
Vibratome | Vibratome | Series 1000 | Block slicing into 500 µm thick slices |
Name | Company | Catalog Number | Comments |
MEA system: | |||
Multielectrode array (MEA) probes: 6 x 10 planar MEA | Multi Channel Systems | 60MEA500/30iR-Ti-pr MEAS 6×10 | electrode diameter, 30 µm; electrode spacing, 500 µm; impedance, 50 kΩ at 200 Hz |
Multielectrode array (MEA) probes: 8 x 8 MEA | Ayanda Biosystems | 60MEA200/10iR-Ti-pr MEAS 8×8 | pyramidal-shaped electrode; diameter, 40 µm; tip height, 50 µm; electrode spacing, 200 µm; impedance, 1000 kΩ at 200 Hz |
A 60-channel amplifier was used with a band-pass filter set between 0.1 Hz and 3 KHz at 1200X amplification | Multi-Channel Systems | MEA-1060-BC | |
MC Rack software at a 10 KHz sampling rate | Multi-Channel Systems | Software for data collect and recordings | |
control of a pulse generator | Multi-Channel Systems | STG 1002 | |
slice anchor kits and hold-downs | Warner Instruments | SHD-26H/10; WI64-0250 | |
Peristaltic Pump-minipuls3 | Gilsom | MINIPULS3 | perfusion rate : 8 ml/min |
Name | Company | Catalog Number | Comments |
Stimulation system: | |||
Isolated stimulator | A-M Systems | Model 2100 | intensity of ±350 μA , duration of 200 μs |
Tungsten electrode | A-M Systems | 575300 | placed in thalamus |