34. International Epilepsy Conference, 28 August - 01 September 2021, pp.93-94
The role of various type of neurotransmitters such as gamma aminobutyric acid (GABA) or dopamine across cortico-thalamic circuit and basal ganglia in the absence seizure mechanisms has been previously examined by several studies. The ontogenesis of spike-and-wave discharges (SWDs) of absence epilepsy change with age in which cortical maturation completes at around 3 to 4 month-old genetic absence epilepsy rats. We aimed to compare the immunoreactivity (ir) of dopaminergic and GABAergic neurons in the striatum and substantia nigra (SN) of the 2 month-old non-epileptic Wistar control and genetic absence epilepsy rats from Strasbourg (GAERS).
Wistar rats and GAERS were anesthetized with ketamine and xylazine and transcardially perfused with saline followed by 10% paraformaldehyde. Coronally cut free-floating sections (40 µm-thick) of striatum and SN were used for immunohistochemical procedures of thyrosine hydroxylase (TH, dopaminergic neurons) and parvalbumin (PRV, GABAergic interneurons). Photomicrographs captured via an Olympus DP72 microscope (Tokyo, Japan) were used for densitometric analysis (Image J software, USA). Data were expressed as mean±standard error of mean and analyzed by using GraphPad Prism.
Comparison of TH-ir in the striatum and SN pars compacta and PR-ir in the striatum and SN pars reticulata between Wistar and GAERS was found not to be statistically significant. Also there was no difference between the groups for mean number of PRV positive GABAergic interneurons of striatum or SN pars reticulata.
Our findings on dopaminergic and GABAergic transmission in the basal ganglia for the underlying mechanisms of epileptogenesis in the absence epilepsy provide insight into the mechanisms of epileptogenesis in absence epilepsy.
This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK-SBAG-218S653).