No loss of somatostatin-immunoreactive neurons in the hippocampal dentate hilus of alcohol-withdrawal-kindled rats.

Abstract

The neuropeptide somatostatin has been suggested to play a role in seizure genesis, electrical kindling and the neurotoxic effects of alcohol. The purpose of the present experiment was to study somatostatin-immunoreactive (SS-IR) neurons in hippocampus during alcohol-withdrawal kindling. Alcohol-withdrawal kindling was performed by subjecting male Wistar rats to seven weekly episodes consisting of 2 days of severe alcohol intoxication and 5 days of alcohol withdrawal. Then the kindled animals (multiple withdrawal group) and a single withdrawal group, which was fed isocalorically with the kindled animals during episodes 1-7, were exposed to 4 days of severe alcohol intoxication (episode 8). During the following withdrawal, the seizure activity was observed 9-15 h after last alcohol dose, in order to subdivide the animals from these two groups into groups with and without seizures. Subsequently, SS-IR neurons were visualized immunocytochemically and counted in the hilus of the dentate gyrus (hippocampus). The number of SS-IR neurons per unit area of the hilus was neither affected by a single nor by multiple episodes of alcohol withdrawal. We therefore concluded that a loss of these neurons is not involved in the development of alcohol-withdrawal-kindled seizures.