title: Ionic current correlations underlie the global tuning of large numbers of neuronal activity attributes.
abstract: Ionic conductances in identified neurons are highly variable. This poses the crucial question of how such neurons can produce stable activity. Coexpression of ionic currents has been observed in an increasing number of neurons in different systems, suggesting that the coregulation of ionic channel expression, by thus linking their variability, may enable neurons to maintain relatively constant neuronal activity as suggested by a number of recent theoretical studies. We examine this hypothesis experimentally using the voltage- and dynamic-clamp techniques to first measure and then modify the ionic conductance levels of three currents in identified neurons of the crab pyloric network. We quantify activity by measuring 10 different attributes (oscillation period, spiking frequency, etc.), and find linear, positive and negative relationships between conductance pairs and triplets that can enable pyloric neurons to maintain activity attributes invariant. Consistent with experimental observations, some of the features most tightly regulated appear to be phase relationships of bursting activity. We conclude that covariation (and probably a tightly controlled coregulation) of ionic conductances can help neurons maintain certain attributes of neuronal activity invariant while at the same time allowing conductances to change over wide ranges in response to internal or environmental inputs and perturbations. Our results also show that neurons can tune neuronal activity globally via coordinate expression of ion currents.
authors.affiliation: Federated Department of Biological Sciences, New Jersey Institute of Technology and Rutgers University, Newark, New Jersey 07102, USA.
authors.forename: Shunbing
authors.initials: S
authors.lastname: Zhao
authors.forename: Jorge
authors.initials: J
authors.lastname: Golowasch
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D055592:Biophysical Phenomena / Q000187:drug effects; D003386:Brachyura; D004558:Electric Stimulation; D017952:Ganglia, Invertebrate / Q000166:cytology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D011708:Pylorus / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013223:Statistics as Topic; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D007473:Ion Channels; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin