RT Journal Article
SR Electronic
T1 Modulation of potassium current kinetics in bag cell neurons of Aplysia by an activator of adenylate cyclase
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 2772
OP 2783
DO 10.1523/JNEUROSCI.04-11-02772.1984
VO 4
IS 11
A1 JA Strong
YR 1984
UL http://www.jneurosci.org/content/4/11/2772.abstract
AB The bag cell neurons of Aplysia are neurosecretory cells which control egg-laying behavior. In their resting state, the cells have a high resting potential and show no spontaneous activity. In response to brief stimulation of a neural input, the cells depolarize and fire repetitively for up to 60 min. This afterdischarge is thought to be controlled by elevations of intracellular adenosine 3′:5′-monophosphate (cAMP). A voltage clamp study of bag cells in primary culture was undertaken in order to characterize the effects of cAMP on the cells' electrical properties. The transient outward potassium current (A- current) was studied before and after the application of forskolin (an activator of adenylate cyclase) and RO20–1724 (a phosphodiesterase inhibitor). These drugs reduced the amplitude of the A-current, primarily by speeding the inactivation process. The time constants for inactivation were speeded at all potentials, but the largest effects were seen at the more positive potentials (-40 to -15 mV), where the time constants were reduced 5-fold. Neither the activation process nor the steady-state parameters of inactivation were altered by the drugs. It is suggested that these changes in the A-current could explain the ability of the bag cells to fire repetitively during the afterdischarge.