title: Calcium store depletion induces persistent perisomatic increases in the functional density of h channels in hippocampal pyramidal neurons.
abstract: The regulation of intracellular calcium by the endoplasmic reticulum (ER) plays a critical role in neuronal function. While the consequences associated with depleting calcium from the ER have been studied in multiple systems, it is not known whether the intrinsic properties of a neuron change in response to such perturbations. In this study, we demonstrate that the depletion of calcium from the ER of hippocampal CA1 pyramidal neurons induces a persistent, perisomatic increase in the density of functional h channels resulting in a reduction in intrinsic excitability and an increase in the optimal response frequency. This form of intrinsic plasticity is dependent on the elevation of cytoplasmic calcium, inositol triphosphate receptors, store-operated calcium channels, and the protein kinase A pathway. We postulate that this form of depletion-induced intrinsic plasticity is a neuroprotective mechanism that reduces excitability after depletion of calcium stores triggered through altered network activity during pathological conditions.
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Rishikesh
authors.initials: R
authors.lastname: Narayanan
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Dougherty
authors.forename: Daniel
authors.initials: D
authors.lastname: Johnston
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D066298:In Vitro Techniques; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D008297:Male; D015221:Potassium Channels / Q000378:metabolism*; D017966:Pyramidal Cells / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015290:Second Messenger Systems / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology
chemical_list: D015220:Calcium Channels; D054815:Cyclic Nucleotide-Gated Cation Channels; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D015221:Potassium Channels; D017868:Cyclic AMP-Dependent Protein Kinases; D002118:Calcium