Effects of excitatory amino acid antagonists on social recognition of male rats.
The effects of NMDA and non-NMDA glutamate receptor antagonists were evaluated on social recognition of adult male rats. Adult animals were injected (s.c.) with drug or saline immediately after the initial exposure to a juvenile male, 21-24 days old, and re-exposed to the same or to a novel juvenile 30min later. If the time spent by animals in social investigation during re-exposure to the same juvenile was comparable with the time measured during the initial exposure and with the time of animals re-exposed to a novel juvenile, the effect of a drug was designated as amnesia. Such an effect was found in adult animals administered 1 and 1.5mg/kg phencyclidine, 0.1mg/kg dizoclipine, 2.5mg/kg CPP, and 4mg/kg CGS 19755. Amnesic effects were observed at doses not affecting motor performance. No amnesic effect was produced by CNQX and NBQX (2.5, 5 and 10mg/kg). These results show that while recognition capacity in adult male rats is disrupted by several NMDA antagonists, non-NMDA antagonists do not interfere with short-term retention of individual odours. This suggests that NMDA glutamate receptors may be involved in the processing of socially relevant olfactory information.
Research Institute for Pharmacy and Biochemistry, Kourimská 17, 130 60 Prague 3, Czech Republic.
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