The effects of the peptide FMRFamide (Phe-Met-Arg-PheNH,) on the soma of neuron R14 in the abdominal ganglion of Aplysia californica and A. brasiliana were characterized. Pressure-ejected FMRFamide caused 3 types of responses, (1) a fast outward current (duration, ~30 set), (2) a fast inward current (duration, ~20 set), and (3) a slow inward current (peak at 0.5-l min; duration, 2-3 min). The s...

Cephalopods, such as sepia, squid, and octopus, show a well-developed and sophisticated control of balance particularly during prey capture and escape behaviors. There are two separate areas of sensory epithelium in cephalopod statocysts, a macula/statolith system, which detects linear accelerations (gravity), and a crista/cupula system, which detects rotational movements. The aim of this study...

The double sucrose-gap voltage-clamp technique was applied to frog atrial tissue to investigate the ionic currents responsible for the action potential in this tissue. Membrane depolarization elicited two distinct components of inward current when the test node was exposed to normal Ringer solution: a fast inward current and a slow inward current. The fast inward current appeared to be carried ...

The voltage-dependent currents of isolated Necturus lingual cells were studied using the whole-cell configuration of the patch-clamp technique. Nongustatory surface epithelial cells had only passive membrane properties. Small, spherical cells resembling basal cells responded to depolarizing voltage steps with predominantly outward K+ currents. Taste receptor cells generated both outward and inw...

We have measured the NaCl or KCl currents under voltage clamp across the dorsal lingual epithelium of the rat and simultaneously the response of the taste nerves. Under short-circuit conditions a NaCl stimulus evoked an inward current (first current) that coincided with excitation of the chorda tympani. This was followed by a slower inward current (second current) that matched the kinetics of t...

This report presents studies on ionic currents in Aplysia motoneuron B16 that are modulated by the neuropeptide egg-laying hormone (ELH) of Aplysia. ELH induces an inward current that persists in the presence of the peptide and that decays slowly after ELH is removed from the bath. The effect is not due to a decrease in the delayed potassium current, the calcium-activated potassium current, or ...

In Limulus ventral photoreceptors, illumination not only increases a specialized light-activated sodium conductance but also modulates voltage-dependent conductances. Previous work has demonstrated that the delayed rectifier current is reduced by light; we report here that the early voltage-dependent inward current is also reduced by light. Furthermore, by maintained during continuous depolariz...