Purine receptors and kynurenic acid modulate the somatosensory evoked potential in rat cerebral cortex.
Adenosine and analogues, and antagonists to adenosine and putative excitatory amino acid transmitters were topically applied to the cerebral cortex of urethane-anaesthetised rats and their effects on the somatosensory evoked potentials (SEPs) examined. 2-Chloro-adenosine decreased the amplitude of the SEPs whereas adenosine did not. Both L-(-)N6-phenyl-isopropyladenosine (L-PIA) and 5'-N-ethylcarboxamide adenosine (NECA) depressed the SEPs; the effect of L-PIA was more marked than that of NECA. 8-p-Sulphophenyl theophylline increased the amplitude of the SEPs and also inhibited the effects of 2-chloro-adenosine and L-PIA. Kynurenic acid decreased the amplitude of the SEPs. The results suggest that the initial component of the SEP is a post-synaptic event and that endogenous adenosine probably modulates thalamo-cortical synaptic transmission.
D015762:2-Chloroadenosine; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology*; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects*; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D007736:Kynurenic Acid / Q000494:pharmacology*; D008297:Male; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011983:Receptors, Purinergic / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects
D011983:Receptors, Purinergic; D015762:2-Chloroadenosine; D010660:Phenylisopropyladenosine; D019830:Adenosine-5'-(N-ethylcarboxamide); D007736:Kynurenic Acid; D000241:Adenosine