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The sigma‐1 receptor modulates NMDA receptor synaptic transmission and plasticity via SK channels in rat hippocampus
Author(s) -
Martina Marzia,
Turcotte MarieEve B.,
Halman Samantha,
Bergeron Richard
Publication year - 2007
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2006.116178
Subject(s) - nmda receptor , long term potentiation , neuroscience , neurotransmission , excitatory postsynaptic potential , chemistry , synaptic plasticity , agonist , postsynaptic potential , hippocampus , receptor , biology , inhibitory postsynaptic potential , biochemistry
The sigma receptor (σR), once considered a subtype of the opioid receptor, is now described as a distinct pharmacological entity. Modulation of N ‐methyl‐ d ‐aspartate receptor (NMDAR) functions by σR‐1 ligands is well documented; however, its mechanism is not fully understood. Using patch‐clamp whole‐cell recordings in CA1 pyramidal cells of rat hippocampus and (+)pentazocine, a high‐affinity σR‐1 agonist, we found that σR‐1 activation potentiates NMDAR responses and long‐term potentiation (LTP) by preventing a small conductance Ca 2+ ‐activated K + current (SK channels), known to shunt NMDAR responses, to open. Therefore, the block of SK channels and the resulting increased Ca 2+ influx through the NMDAR enhances NMDAR responses and LTP. These results emphasize the importance of the σR‐1 as postsynaptic regulator of synaptic transmission.