Kainic acid has cell-specific effects on survival of hypothalamic mouse neurones in vitro.

Cultures of mouse hypothalamus from embryonic day 15 fetuses were exposed to kainic acid (KA) to study effects on survival of selected cell populations. After 6 days in vitro, immunocytochemistry revealed destruction of dopaminergic and GABAergic neurones after KA-treatment, whereas numbers of oxytocinergic cells and neurones containing metEnkephalin were unchanged. Surviving neurones were characterized by a loss of processes or a reduction of process length. Glial cell numbers did not show any differences between groups. Amino acid concentrations decreased after KA-treatment; only glutamine and taurine levels were unaffected. We conclude that toxic effects of KA differ with respect to distinct neuronal populations of the mouse hypothalamus. Therefore, experimental data concerning neuronal destruction under in vitro conditions have to take into account the selectivity of this neurotoxic agent.