title: Long-lasting inhibition of neuron R15 of Aplysia: role of the interneuron II network.
abstract: Stimulation of the branchial or either connective nerve of the abdominal ganglion of Aplysia californica evokes simultaneous responses in cells R15, L8, L9, and L11 which are indistinguishable from those arising from spontaneous interneuron II (INT II) activity. Threshold for the INT II-like response in all cells is identical, suggesting that the response is mediated by INT II activity. The magnitude of the response in each cell increases with stimulus intensity and is subject to both temporal and spatial summation, implying the existence of multiple fibres in each nerve which converge on INT II. Repetitive stimulation evokes long-lasting inhibition in R15. The onset of this phenomenon is always accompanied by an INT II burst in the other follower cells. Long-lasting inhibition in R15 is not accompanied by prolonged INT II activity, suggesting an endogenous mechanism of inhibition. The phosphodiesterase inhibitor, IBMX, potentiates the response of R15 to nerve stimulation without affecting threshold for the response. This is consistent with inhibition by a mechanism endogenous to R15.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D001048:Aplysia; D004558:Electric Stimulation; D007395:Interneurons / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology*; D013997:Time Factors
chemical_list: D015056:1-Methyl-3-isobutylxanthine