Dependence of Variability of Neuronal Responses in the Frog Torus Semicircularis on the Parameters of Acoustic Stimuli

作者：Bibikov N G^*

来源：Neurophysiology, 2014, 46(1): 16-24.

DOI：10.1007/s11062-014-9401-1

• auditory system
• amphibians
• torus semicircularis
• variability
• Fano factor
• neuron
• reaction to the signal

Responses of neurons of various sensory nuclei to presentation of specific stimuli can be characterized not only by the mean number of action potentials (APs) in such reactions and the pattern of AP time distribution, but also by the level of repeatability of the reaction. We studied impulse responses of neurons localized in the auditory center of the midbrain of the grass frog under the action of tone segments of a characteristic frequency, with an unmodulated or modulated amplitude. The repeatability of reactions was evaluated according to the ratio between the variation of the number of APs to presentations of the signal and the mean number of APs in the response (Fano factor). Neurons differed noticeably from each other in this characteristic. In the studied sampling, we observed no close correlation between the Fano factor and the mean number of APs in the response, although in some cells such correlation may appear rather significant. In the case of the action of low-intensity signals, an increase in the intensity resulted, on average, in the improvement of repeatability of the reaction; with higher levels of the signal, this trend, however, was not maintained. Complication of the signal using amplitude modulation usually caused a decrease in the variability, although in some cells the pattern of such dependence was opposite. We found a trend toward a rise in the Fano factor with increase in the duration of the time interval of observation. We focus our attention on the correlation between stochastic reactions of separate cells of sensory systems and variability of responses of the entire organism at fixed sensory stimulations.

• 出版日期2014-2