title: Purine receptors and kynurenic acid modulate the somatosensory evoked potential in rat cerebral cortex.
abstract: 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.
mesh_terms: 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
chemical_list: D011983:Receptors, Purinergic; D015762:2-Chloroadenosine; D010660:Phenylisopropyladenosine; D019830:Adenosine-5'-(N-ethylcarboxamide); D007736:Kynurenic Acid; D000241:Adenosine