title: The effects of cholecystokinin and cholecystokinin antagonists on synaptic function in the CA1 region of the rat hippocampal slice.
abstract: The effects of two CCK antagonists, benzotript and proglumide, and of sulfated and non-sulfated cholecystokinin octapeptide (CCK-8-S and CCK-8-NS), were studied in the CA1 region of the rat hippocampal slice. Both benzotript and proglumide shifted presynaptic volley (prevolley) vs population spike input/output (I/O) curves for Schaffer collateral-commissural synaptic transmission to the right. This result indicates that the antagonists had a net depressant effect on synaptic transmission. CCK-8-S shifted prevolley vs population spike I/O curves to the left, indicating a net excitatory effect. Analysis of component I/O curves indicated that CCK-8-S and the CCK antagonists were acting postsynaptically by changing CA1 pyramidal cell threshold. CCK-8-NS had no significant effect on overall or component I/O functions. These findings suggest that endogenous CCK is released, directly or indirectly, upon stimulation of the Schaffer collateral-commissural fibers and increases the excitability of CA1 pyramidal cells.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D005260:Female; D005973:Glutamine / Q000031:analogs & derivatives*; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D011377:Proglumide / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012844:Sincalide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013431:Sulfates / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects* / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D001549:Benzamides; D013431:Sulfates; D005973:Glutamine; D011377:Proglumide; C013841:benzotript; D012844:Sincalide