PACAP-INDUCED DEPOLARIZATIONS IN HAMSTER SUBMANDIBULAR GANGLION NEURONS

TAKASHI SUZUKI, HIROHITO ONO, HIDEAKI IKEGAMI
2003 The Bulletin of Tokyo Dental College  
In this study, we have investigated the effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on in vitro hamster submandibular ganglion neurons using the conventional intracellular recording technique. PACAP (10M) induced slow depolarizations in approximately 70% of tested cells. PACAP-induced depolarizations were approximately 10mV in the peak amplitude, and their durations were approximately 10 min. The slow depolarizations were accompanied by a decrease in membrane
more » ... e (g m ) at the initial phase and an increase in g m at the peak phase. Membrane input resistance increased by ‫%2.2ע8.41‬ (mean‫ע‬S.E., max.) of the resting value at the initial phase and decreased by ‫%3.4ע8.03‬ (max.) at the peak phase. Anodal break spikes were elicited at the initial phase during PACAP-induced depolarization. In one neuron, anodal break spikes were elicited at the peak. Spikes which followed the anodal break spike were also elicited at 4Hz in the initial phase during the slow depolarizations. The decrease in g m was probably produced by an inhibition of calcium conductance and an inhibition of slow Ca ‫ם2‬ -activated K ‫ם‬ channels, while the increase in g m might have been produced by an activation of nonselective cation channels. The slow depolarizations by PACAP might be mediated by a membrane-delimited signal transduction cascade involving G protein in the submandibular ganglion neurons.
doi:10.2209/tdcpublication.44.21 pmid:12772583 fatcat:rjh3bbhjdnbn5atdmibi3jvmcy