Down-regulation of protein kinase C blocks 5-HT-induced enhancement in Hermissenda B photoreceptors.
Light paired with serotonin (5-HT) in vivo produces both short and long-term enhancement of generator potentials in identified B-photoreceptors in Hermissenda. The contribution of protein kinase C to the induction of enhancement was assessed by pretreatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which produces a depletion or down-regulation of protein kinase C. Presentation of light and 5-HT after an 8 h pretreatment with TPA blocked the induction of enhancement of light-evoked generator potentials. Typical enhancement produced by light and 5-HT was observed after pretreatment with an inactive phorbol (4 alpha-phorbol). These results indicate that activation of protein kinase C is an important step in the induction of enhancement.
Crow
T
T
Department of Neurobiology and Anatomy, University of Texas Medical School, Houston 77225.
Forrester
J
J
Williams
M
M
Waxham
M N
MN
Neary
J T
JT
D000818:Animals; D015536:Down-Regulation; D008027:Light; D008974:Mollusca; D010786:Photoreceptor Cells / Q000187:drug effects*; D011493:Protein Kinase C / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D012702:Serotonin Antagonists; D012701:Serotonin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate