Transcranial focal electrical stimulation via concentric ring electrodes in freely moving cats: Antiepileptogenic and postictal effects

Abstract

Transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCRE), tripolar TFS, is proposed to treat pharmacoresistant epilepsy. We determined the effect of tripolar TFS on electrical amygdaloid kindling (AK) in freely moving cats. Fifteen cats were bilaterally implanted with electrodes in the amygdala (AM) and prefrontal cortex and assigned to three groups: the control group, which only received AK; the tripolar TFS before AK group, in which TCREs were placed over the vertex and tripolar TFS (300 Hz, 200 μs biphasic equal charge, square pulses) was delivered for 40 min just prior to AK; and the tripolar TFS after AK group, in which the TCREs were placed over the temporal bone ipsilateral to the kindled AM, while tripolar TFS was administered for 2 min just after AK onset for 40 days, and, thereafter, only AK was applied. AK was applied daily until all animals reached kindling stage VI. A three concentric spheres finite element cat head model was developed to analyze the electric fields caused by tripolar TFS. Tripolar TFS after AK inhibited kindling development. Animals with tripolar TFS after AK remained at the focal seizure stages for 20 days after tripolar TFS cessation and required 80.0 ± 15.42 AK stimulations to reach stage VI, significantly higher than TFS before AK, and control (P < .001). Tripolar TFS before AK did not show signs of protection against epileptogenesis. The finite modeling of tripolar TFS showed that the electric field is >0.3 mV/mm at depths less than approximately 12.6 mm in the cat brain, which should be strong enough to alter brain activity. In conclusion, tripolar TFS applied via a TCRE over the ipsilateral temporal area significantly delayed AK. This taken together with other reports of tripolar TFS aborting seizures in acute seizure models suggests that tripolar TFS is a promising new modality that should be considered for further testing.

Genoarchitectonic Compartmentalization of the Embryonic Telencephalon: Insights From the Domestic Cat

“…These results, along with the fact that the feline brain is gyrencephalic, suggest that cats can provide a useful animal model in the study of the brain in ontogenesis and evolution. To our knowledge, this is the first systematic analysis of the feline telencephalon genoarchitecture and we hope that it will provide a reference for future research, especially given the re-appearance of this species in neuroscience research ( Hinova-Palova et al, 2019 ; Valdés-Cruz et al, 2019 ; Graff et al, 2020 ).…”

A microfluidic perspective on conventional in vitro transcranial direct current stimulation methods

“…Two additional papers were included based on the citation history of all the included articles. In addition to rodents, ten studies using cats ( Schweid et al, 2008 ; Bolzoni et al, 2013 ; Valdés-Cruz et al, 2019 ; Zhao et al, 2020 ; Ding et al, 2021 ; Pan et al, 2021 ), ferrets ( Fröhlich and McCormick, 2010 ; D’Andola et al, 2018 , 2019 ), or monkeys ( Krause et al, 2017 ) were included. Among these included 213 papers, most studies applied tDCS in vivo to disease animal models (107 papers) or naïve animals (75 papers), while only 34 studies conducted in vitro experiments.…”

Workshops of the eighth international brain–computer interface meeting: BCIs: the next frontier

“…TCREs are safe for stimulation [20,21] and can be used for seizure control [22][23][24][25][26]. The stimulation can block epileptogenesis [27] and alter neurotransmitters to increase the effectiveness of anti-seizure drugs [28][29][30]. Stimulation experiments are underway to determine if transcranial focal stimulation via concentric ring electrodes is effective for modulating human brains.…”