Enhanced Excitability of the Neonatal Rat Hippocampus After Acute Exposure to Ethanol

Nailya Lotfullina , Andrey Zakharov (1) , Roustem Khazipov (2, 3, 4, 5)

1 Laboratory of Neurobiology
2 AMU - Aix Marseille Université
3 INMED - INSERM U901 - Institut de Neurobiologie de la Méditerranée [Aix-Marseille Université]
4 INSERM - Institut National de la Santé et de la Recherche Médicale
5 KFU - Kazan Federal University

Enhanced excitability manifested by seizures and epilepsy is one of the characteristic features of the fetal alcohol spectrum disorders (FASD). Here, we examined network excitability using a high-potassium model in the hippocampal slices prepared from the postnatal days of P7-9 rats treated with ethanol. Ethanol was administered at 6 g/kg intraperito-neally 12 h before the slice preparation. The extracellular field potential recordings from the hippocampal slices using multishank silicon probes placed along CA3-CA1 axis were performed in the interface chamber. We found that elevation of the extracellular potassium from 3.5 to 6 mM evoked seizure-like clonic or tonic-clonic discharges in 77 % of the slices from the ethanol-treated animals and only in 15 % of the slices from the control animals. Further elevation of the extra-cellular potassium to 8.5 mM evoked epileptiform activity in 92 and 69 % of the slices from the ethanol-treated and the control animals, respectively. The current source density profile and the multiple unit activity analysis pointed on the CA3 hippocampal region as a generator of the epileptiform activity. Thus, the hippocampal slices from the ethanol-treated neonatal rats display enhanced excitability and could serve as a FASD model to study the early epileptiform transformations following exposure to ethanol.

Mots clés: Alcoholism; Fetal alcohol syndrome; Hippocampus; Seizure; Neonate

Domaines: Neurosciences [q-bio.NC]

Nailya Lotfullina, Andrey Zakharov, Roustem Khazipov. Enhanced Excitability of the Neonatal Rat Hippocampus After Acute Exposure to Ethanol. BioNanoScience, 2017, 7 (1), pp.119-122. ⟨10.1007/s12668-016-0321-y⟩. ⟨hal-01962313⟩