Different Firing Patterns of Celiac Neurons in DOCA‐salt hypertensive and Normotensive Rats

Abstract

It is not known if changes in the electrophysiological properties of sympathetic ganglia neurons contribute to increased activity in hypertension. Using whole-cell patch clamp of dissociated neurons the resting membrane potential, membrane resistance and membrane capacitance of neurons from hypertensive rats were not different in neurons from normotensive rats. Neurons were divided into five groups based on their action potential (AP) firing patterns to increasing amounts of constant suprathreshold depolarizing current (20–100pA; 400 ms). Group 1 fired only 1 AP; Group 2 fired several APs and adapted quickly; Group 3fired several APs and adapted slowly; Group 4 fired continuously during low level current injection, but fired only a shout burst during higher level current injection; Group 5 fired continuously in response to all levels of depolarizing current. The distribution of these five groups was significantly different in neurons from hypertensive rats (n=68) using X2 test. There were more Group 4 neurons and less Group 3 neurons in hypertensive rats; although the average instantaneous firing frequency in each group was the same in hypertensive rats compared to normotensive rats. These differences indicate that in hypertensive rats a larger subset of celiac neurons firing more APs by depolarization compared to normotensive rats. Support HL70687