ELECTROPHYSIOLOGICAL PROPERTIES AND CHEMOSENSITIVITY OF ACUTELY ISOLATED NODOSE GANGLION NEURONS OF THE RABBIT

Neurons in the nodose ganglion were enzymatically dissociated from adu lt rabbits and electrophysiologically examined within 2 h. About 90% o f the neurons survived the dissociation procedure. Their resting membr ane potential (- 59 +/- 0.6 mV), time constant (5.7 +/- 0.5 ms), input resistance (80 +/- 5.3 MOMEGA), action potential properties (amplitud e, 79 +/- 1.2 mV; overshoot 21 +/- 10 mV; duration 5.2 +/- 0.1 ms; thr eshold, - 38 +/- 0.9 mV; and fast spike after hyperpolarizaton, 10 +/- 0.5 mV, 64 +/- 3.8 ms) were not different from values obtained from n odose neurons in intact ganglion in vitro and in vivo. An unusually lo ng duration spike afterhyperpolarization observed in about 35% of nodo se neurons in intact ganglion was demonstrated in about 28% of the acu tely isolated neurons. The percentage of isolated neurons responding t o bath applied acetylcholine, bradykinin, serotonin and histamine was similar to those reported for neurons in the intact ganglia. We conclu de that the electrophysiological and chemoreceptive properties of acut ely isolated adult rabbit nodose neurons are similar to those observed for neurons in intact ganglia. Thus the availability of large numbers of acutely isolated adult nodose neurons should allow multidisciplina ry studies of vagal afferent C-fiber neurons not readily obtainable in the intact ganglion.