title: Reduced threshold for induction of LTP by activation of dopamine D1/D5 receptors at hippocampal CA1-subiculum synapses.
abstract: The phasic release of dopamine in the hippocampal formation has been shown to facilitate the encoding of novel information. There is evidence that the subiculum operates as a detector and distributor of sensory information, which incorporates the novelty and relevance of signals received from CA1. The subiculum acts as the final hippocampal relay station for outgoing information. Subicular pyramidal cells have been classified as regular- and burst-spiking neurons. The goal of the present study was to study the effect of dopamine D1/D5 receptor activation on synaptic transmission and plasticity in the subicular regular-spiking neurons of 4-6 week old Wistar rats. We demonstrate that prior activation of D1/D5 receptors reduces the threshold for the induction of long-term potentiation (LTP) in subicular regular-spiking neurons. Our results indicate that D1/D5 receptor activation facilitates a postsynaptic form of LTP in subicular regular-spiking cells that is NMDA receptor-dependent, relies on postsynaptic Ca(2+) signaling, and requires the activation of protein kinase A. The enhanced propensity of subicular regular-spiking cells to express postsynaptic LTP after activation of D1/D5 receptors provides an intriguing mechanism for the encoding of hippocampal output information.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charite, Universitätsmedizin Berlin, Berlin, Germany. roggenhofer@cbs.mpg.de
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Roggenhofer
authors.forename: Pawel
authors.initials: P
authors.lastname: Fidzinski
authors.forename: Oded
authors.initials: O
authors.lastname: Shor
authors.forename: Joachim
authors.initials: J
authors.lastname: Behr
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000502:physiology*; D020013:Calcium Signaling; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004558:Electric Stimulation; D004789:Enzyme Activation; D005260:Female; D017774:Long-Term Potentiation; D008297:Male; D008564:Membrane Potentials; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D050641:Receptors, Dopamine D5 / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D017447:Receptors, Dopamine D1; D016194:Receptors, N-Methyl-D-Aspartate; D050641:Receptors, Dopamine D5; D017868:Cyclic AMP-Dependent Protein Kinases