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Protein kinase C‐mediated enhancement of glycine response in rat sacral dorsal commissural neurones by serotonin.
Author(s) -
Xu T L,
Nabekura J,
Akaike N
Publication year - 1996
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.1996.sp021701
Subject(s) - protein kinase c , chelerythrine , long term potentiation , pertussis toxin , chemistry , serotonin , endocrinology , medicine , bapta , 5 ht receptor , agonist , receptor , biology , g protein , kinase , biochemistry
1. The modulatory effect of serotonin (5‐hydroxytryptamine, 5‐HT), on the glycine (Gly) response was investigated in neurones acutely dissociated from the rat sacral dorsal commissural nucleus (SDCN) using a nystatin‐perforated patch recording configuration. 2. 5‐HT potentiated the 10(‐5) M Gly‐induced Cl‐ current (IGly) in a concentration‐dependent manner without changing the reversal potential of the Gly response or the affinity of Gly to its receptor. 3. alpha‐Methyl‐5‐HT mimicked and ketanserine blocked the 5‐HT action on IGly, thus indicating the 5‐HT2 receptor‐mediated enhancement. 4. Phorbol‐12‐myristate‐13‐acetate and 1‐oleoyl‐2‐acetylglycerol potentiated IGly. The subsequent application of 5‐HT slightly increase IGly. Chelerythrine blocked the enhancement of IGly by 5‐HT, thus suggesting the involvement of protein kinase C (PKC) in the pathway of 5‐HT action on IGly. 5. Pertussis toxin (IAP) treatment did not block the facilitatory effect of 5‐HT on IGly. 6. BAPTA AM did not disturb the 5‐HT‐induced potentiation of IGly, thus suggesting that [Ca2+]i is not involved in the 5‐HT effect. 7. In conclusion, activation of a 5‐HT2 receptor coupled to an IAP‐insensitive G‐protein increases intracellular diacylglycerol (DAG) formation. The accumulation of DAG also increases the Ca(2+)‐independent PKC activity, thus resulting in the potentiation of the Gly response in the SDCN neurones.