We characterized whole cell barium currents through calcium channels and investigated the effects of serotonin (5-HT) on calcium channel currents and firing behavior in visualized caudal raphe neurons of the neonatal rat in brain stem slices (n = 201). A subpopulation of recorded neurons was recovered after staining for tryptophan hydroxylase (TPH), the 5-HT synthesizing enzyme (n = 21); of tho...

Nociceptive sensory neurons are unusual in expressing voltage-gated inward currents carried by sodium channels resistant to block by tetrodotoxin (TTX) as well as currents carried by conventional TTX-sensitive sodium channels and voltage-dependent calcium channels. To examine how currents carried by each of these helps to shape the action potential in small-diameter dorsal root ganglion cell bo...

Calcium currents were studied in isolated "swim motor neurons" from the jellyfish Polyorchis penicillatus, using the tight-seal, whole-cell, voltage-clamp technique. Two high-voltage-activated (HVA) currents were observed. The transient current, HVA-t, activated rapidly (time to peak, 4 msec), inactivated with two time constants (26 msec, 187 msec) in a positive voltage range (Vi = -23 mV), and...

Microphotolysis and confocal microscopy were used to investigate the timing of calcium release and of the electrical response in Limulus polyphemus ventral photoreceptors. The fluorescent dyes Fluo-3 and Calcium Green-5N were used to monitor local Ca2+ elevations. Photolysis of caged inositol trisphosphate (InsP3) close to the plasma membrane of the light-sensitive rhabdomeral (R-) lobe resulte...