Loss of extrasynaptic channel modulation by protein kinase C underlies the selection of serotonin responses in an identified leech neuron

• Published in: Neuron (Cambridge, Mass.) Vol. 8; no. 2; p. 275
• Main Authors: Catarsi, S, Drapeau, P
• Format: Journal Article
• Language: English
• Published: United States 01-02-1992
• Subjects: Animals; Cations - metabolism; Cell Communication - physiology; Cells, Cultured; Ion Channels - drug effects; Ion Channels - physiology; Leeches - physiology; Neurons - physiology; Protein Kinase C - pharmacology; Protein Kinase C - physiology; Serotonin - physiology; Synapses - physiology; Synapses - ultrastructure
• ISSN: 0896-6273
• DOI: 10.1016/0896-6273(92)90294-N

Pressure-sensitive (P) neurons contacted by serotonergic Retzius (R) neurons of the leech in culture selectively reduce a protein kinase C (PKC)-dependent cation response to serotonin and are innervated by the inhibitory, Cl(-)-dependent synapse seen in vivo. We have examined whether the reduction of extrasynaptic cation channel modulation is due to changes in sensitivity of the channels to second messenger. In inside-out membrane patches from single, uncontacted P cells in culture, cation channel activity was increased by rat brain PKC and cofactors. In contrast, the activity of cation channels in patches isolated from P cells paired with R cells was unaffected by PKC. These results demonstrate the loss of extrasynaptic channel modulation by PKC during synapse formation.