| Literature DB >> 17068104 |
Marzia Martina1, Marie-Eve B Turcotte, Samantha Halman, Richard Bergeron.
Abstract
The sigma receptor (sigmaR), 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 sigmaR-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 sigmaR-1 agonist, we found that sigmaR-1 activation potentiates NMDAR responses and long-term potentiation (LTP) by preventing a small conductance Ca2+-activated K+ current (SK channels), known to shunt NMDAR responses, to open. Therefore, the block of SK channels and the resulting increased Ca2+ influx through the NMDAR enhances NMDAR responses and LTP. These results emphasize the importance of the sigmaR-1 as postsynaptic regulator of synaptic transmission.Entities:
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Year: 2006 PMID: 17068104 PMCID: PMC2075134 DOI: 10.1113/jphysiol.2006.116178
Source DB: PubMed Journal: J Physiol ISSN: 0022-3751 Impact factor: 5.182