Synchronized activity of renal neurons and their pattern of discharge in rabbits

Mechanisms of synchronization of renal neurons were studied by correlating its primary features (peak width and peak height of correlation histograms) with parameters derived from interspike-interval histograms of their resting activity. In anaesthetized rabbits the synchronous correlograms had a peak width of 210 ± 8.8 ms (x ± SEM; n = 156) and their peak height was 4.3 ± 2 spikes/s. Following parameters were calculated from interval-histograms of single renal units: the shortest and preferred interspike-intervals (their values were 9 ± 0.5 ms and 11 ± 1 ms, respectively), and longest interspike-interval and spread of histogram (amounting to 5.79 ± 0.45 s and 5.76 ± 0.37 s, respectively). Peak width of cross-correlogram was significantly correlated both with the longest interspike-interval (r = − 0.426) and histogram spread (r =− 0.431) while the strength of relationship with the shortest and preferred interspike-intervals was non-significant. On the other hand, peak height of correlograms was significantly correlated with the longest and preferred interspike-intervals (r = − 0.179 and r = − 0.191) and histogram spread (r = 0.191). These data suggest various properties of both primary features of synchronized firing. They also support the concept of DiBona that various intrarenal effectors may be activated by single renal sympathetic neuron due to information encoded in its discharge pattern.