RT Journal Article
SR Electronic
T1 Intracellular dialysis of cyclic nucleotides induces inward currents in turtle vomeronasal receptor neurons
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1239
OP 1246
DO 10.1523/JNEUROSCI.16-03-01239.1996
VO 16
IS 3
A1 M Taniguchi
A1 M Kashiwayanagi
A1 K Kurihara
YR 1996
UL http://www.jneurosci.org/content/16/3/1239.abstract
AB Turtle vomeronasal receptor neurons in slice preparations were studied using the patch-clamp technique in the whole-cell and cell-attached configurations. The mean resting potential was -48, and the response to an injected current step consisted of either a single spike or a train of spikes. An injected current of 3–30 pA was required to depolarize the neuron to spike threshold near -50 mV. Voltage-clamped vomeronasal receptor neurons displayed transient inward currents followed by sustained outward currents in response to depolarizing voltage steps. In cell-attached recordings, 10 microM forskolin added to the bath caused a transient increase of spike rate. Intracellular application of cAMP evoked ann inward current in a dose-dependent manner from the neurons voltage clamped at -70 mV; 0.1 mM cAMP was sufficient to elicit an inward current in the neurons. The magnitude of the response to cAMP reached a plateau at 1 mM with an average peak amplitude of 176 +/- 34 pA. Intracellular application of 1 mM cGMP also evoked an inward current with an average peak amplitude of 227 +/- 61 pA. The reversal potentials of the induced components were estimated to be 10 +/- 7 mV for cAMP and -4 +/- 16 mV for cGMP. The reversal potential of the cAMP- induced current in external Cl(-)-free solution was similar to that in normal Ringer's solution, suggesting that Cl- current is not significantly involved in the current. The present results represent the first evidence of cyclic nucleotide-activated conductance in the vomeronasal receptor membranes.