Beta-adrenergic agonist-induced long-lasting synaptic modifications in hippocampal dentate gyrus require activation of NMDA receptors, but not electrical activation of afferents.
Isoproterenol induced long-lasting potentiation (LLP) of the medial perforant path-evoked excitatory post-synaptic potential (EPSP) and long-lasting depression (LLD) of the lateral perforant path-evoked EPSP in the absence of perforant path activation. The NMDA receptor antagonist D-(-)-2-amino-5-phosphonovaleric acid [D(-)APV] blocked the induction of LLP and LLD. After wash, a subsequent exposure to isoproterenol induced only LLP of medial perforant path EPSPs; LLD of lateral perforant path-evoked EPSPs did not occur. Our results are consistent with the hypothesis that beta-adrenergic agonist-induced synaptic modifications in the dentate gyrus arise from pre- and postsynaptic events.
Dahl
D
D
Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Sarvey
J M
JM
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects*; D013997:Time Factors
D000318:Adrenergic beta-Agonists; D016194:Receptors, N-Methyl-D-Aspartate; D015763:2-Amino-5-phosphonovalerate; D007545:Isoproterenol