There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The effect of systemically applied salicylate on single-unit firing activity in primary
auditory cortex was investigated in six cats. A dose of 200 mg/kg sodium salicylate
was administered intraperitoneally, and recordings from the same units were performed
prior to application and continuously up to, on average. 6 h after administration.
Local field potentials were used to track the threshold shifts and general input-output
(I/O) behavior following salicylate administration. All animals showed 20-30 dB of
threshold shift about 2 h after administration and showed no recovery during the following
4 h. I/O curves were invariably of the recruitment type. Significant changes were
found in spontaneous firing rates for two groups of unit separately. Low-spontaneous
rate units (initial firing rate < 1 spike/s) showed an increase in spontaneous rate
and high-spontaneous rate units (initial firing rate > 1 spike/s) showed a decrease
in spontaneous firing rate. There were no significant changes in modal and mean values
for interspike-interval (ISI) histograms. The duration-to-rebound peak in the autocorrelation
function for spontaneous firings was prolonged significantly after salicylate administration.
Peak cross-correlation coefficients for the firing patterns of simultaneously recorded
cells showed no significant change but the correlogram's central peak was significantly
narrower after salicylate application. The percentage of firings occurring in bursts
showed no significant change after administration of salicylate. The best modulation
frequency in response to stimulation with periodic click trains decreased after administration.
Both the changes in the spontaneous autocorrelogram and in the temporal modulation
transfer function suggest a prolongation in the duration of the Ca(2+)-activated K+
conductance of the cortical pyramidal cells following salicylate. This suggests that
salicylates affect both the auditory periphery and the auditory cortex.