Variations in the electrophysiological properties of hair cells appear to be a general feature of the vertebrate vestibular sensory organs. Here we studied Ca2+ currents in hair cells of frog crista ampullaris using the whole cell variant of the patch clamp technique. Currents were recorded in situ from hair cells in peripheral, intermediate and central regions of the sensory epithelium. Two types of Ca2+ currents were found: a large nifedipine-sensitive current and a small nifedipine insensitive current. The latter was insensitive to R, P/Q and N-type Ca2+ channels antagonists. The amplitude of nifedipine sensitive and insensitive currents varied in cells along the peripheral region. The present results demonstrate the expression of L and non-L Ca2+ channels in frog crista ampullaris that show intraregional variations in magnitude.
Nature and expression of L and non-L calcium currents by frog crista hair cells
PRIGIONI, IVO;RUSSO, GIANCARLO
2004-01-01
Abstract
Variations in the electrophysiological properties of hair cells appear to be a general feature of the vertebrate vestibular sensory organs. Here we studied Ca2+ currents in hair cells of frog crista ampullaris using the whole cell variant of the patch clamp technique. Currents were recorded in situ from hair cells in peripheral, intermediate and central regions of the sensory epithelium. Two types of Ca2+ currents were found: a large nifedipine-sensitive current and a small nifedipine insensitive current. The latter was insensitive to R, P/Q and N-type Ca2+ channels antagonists. The amplitude of nifedipine sensitive and insensitive currents varied in cells along the peripheral region. The present results demonstrate the expression of L and non-L Ca2+ channels in frog crista ampullaris that show intraregional variations in magnitude.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
