Age-dependent differences in the anticonvulsant effects of 2-amino-7-phosphono-heptanoic acid or ketamine infusions into the substantia nigra of rats.

Infusions of 2-amino-7-phosphonoheptanoic acid (AP7) or ketamine into the substantia nigra pars reticulata (SNPR) of adult rats increase the latency of onset to seizures induced by the convulsant ether flurothyl. Nigral infusions of AP7 or ketamine in concentrations up to 10 times greater than the adult dose are ineffective in 16-day-old rats. These results suggest that differences in seizure susceptibility between adult and immature rats may be related to differences in excitatory amino acid neurotransmission in the SN.