Serotonin (5-HT) applied to the exposed but otherwise intact nervous system results in enhanced excitability
of Hermissenda type-B photoreceptors. Several ion currents in the type-B photoreceptors are modulated
by 5-HT, including the A-type K+ current (IK,A), sustained Ca2+ current (ICa,S), Ca-dependent K+ current (IK,Ca),
and a hyperpolarization-activated inward rectifier current (Ih). In this study,we developed a computational model that
reproduces physiological characteristics of type B photoreceptors, e.g. resting membrane potential, dark-adapted
spike activity, spike width, and the amplitude difference between somatic and axonal spikes. We then used the
model to investigate the contribution of different ion currents modulated by 5-HT to the magnitudes of enhanced
excitability produced by 5-HT. See paper for results and more details. Reference: Cai Y, Baxter DA, Crow T (2003) Computational study of enhanced excitability in Hermissenda: membrane conductances modulated by 5-HT. J Comput Neurosci 15:105-21 [PubMed] |