5-Hz stimulation of CA3 pyramidal cell axons induces a beta-adrenergic modulated potentiation at synapses on CA1, but not CA3, pyramidal cells.
In mouse hippocampal slices, long-term potentiation (LTP) at Schaffer collateral fiber synapses onto CA1 pyramidal cells could be induced by brief trains of 5-Hz synaptic stimulation (30 s) or by longer trains of 5-Hz stimulation (3 min) delivered during beta-adrenergic receptor activation. In contrast, 5-Hz stimulation, either alone or in the presence of the beta-adrenergic receptor agonist isoproterenol, failed to induce LTP at associational-commissural (assoc-com) fiber synapses onto CA3 pyramidal cells. Our results suggest that although CA3 pyramidal cells give rise to both the Schaffer collateral fiber synapses in CA1 and the assoc-com fiber synapses in CA3, the induction of LTP at these synapses may be regulated by different activity- and modulatory neurotransmitter-dependent processes.
Moody
T D
TD
Department of Physiology, Interdepartmental Ph.D. Program for Neuroscience, School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Thomas
M J
MJ
Makhinson
M
M
O'Dell
T J
TJ
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D001369:Axons / Q000502:physiology*; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials; D006624:Hippocampus / Q000502:physiology* / Q000648:ultrastructure; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D017774:Long-Term Potentiation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017966:Pyramidal Cells / Q000648:ultrastructure*; D013569:Synapses / Q000502:physiology*
D000318:Adrenergic beta-Agonists; D007545:Isoproterenol