Properties of voltage-gated sodium channels in developing auditory neurons of the mouse in vitro.
- Author:
Gui MING
1
;
Lu-Yang WANG
Author Information
- Publication Type:Journal Article
- MeSH: Age Factors; Animals; Animals, Newborn; Auditory Pathways; growth & development; physiology; Brain Stem; cytology; growth & development; physiology; Cochlear Nucleus; growth & development; physiology; Electrophysiology; Ion Channel Gating; physiology; Mice; Neurons; physiology; Patch-Clamp Techniques; Sodium Channels; physiology
- From: Chinese Medical Sciences Journal 2003;18(2):67-74
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo investigate the properties of voltage-gated sodium (Na+) channels in developing auditory neurons during early postnatal stages in the mammalian central nervous system.
METHODSUsing the whole-cell voltage-clamp technique, we have studied changes in the electrophysiological properties of Na+ channels in the principal neurons of the medial nucleus of the trapezoid body (MNTB).
RESULTSWe found that MNTB neurons already express functional Na+ channels at postnatal day 1 (P1), and that channel density begins to increase at P5 when the neurons receive synaptic innervation and reach its maximum (approximately 3 fold) at P11 when functional hearing onsets. These changes were paralleled by an age-dependent acceleration in both inactivation and recovery from inactivation. In contrast, there was very little alteration in the voltage-dependence of inactivation.
CONCLUSIONThese profound changes in the properties of voltage-gated Na+ channels may increase the excitability of MNTB neurons and enhance their phase-locking fidelity and capacity during high-frequency synaptic transmission.
