Abstract
Adenosine and adenine nucleotides (5×10-6-10-3M) had inhibitory action on the N-wave (a post-synaptic potential) amplitude of olfactory cortex slices of guinea pig where-as they showed no depressant effect on the PSP of superior colliculus slice. On the contrary 5-HT (10-5M) and GABA (10-4-10-3M) had no inhibitory action on the N-wave of olfactory cortex slice although they depressed markedly the PSP of the slices of superior colliculus.