Noise Enhances Subthreshold Oscillations in Injured Primary Sensory Neurons

Yu-Ying Wang, Zhi-Hong Wen, Jian-Hong Duan, Jun-Ling Zhu, Wen-Ting Wang, Hui Dong, Hui-Ming Li, Guo-Dong Gao, Jun-Ling Xing, San-Jue Hu
2011 Neurosignals  
Introduction Since the early 1990s, numerous studies have shown that noise can play a constructive role in the detection of weak signals in various kinds of peripheral receptors [1] [2] [3] and neurons [4] [5] [6] , which suggested that the receptors and neurons can utilize noise to improve their responsiveness. Most of the results were obtained by extracellular recording, which did not reveal the real changes of membrane potential. In a few data using intracellular recording, the changes of
more » ... ke number induced by noise were shown in hippocampal CA1 neurons [6, 7] , thalamocortical neurons [8] and pyramidal cells [9] . However, the mechanism underlying effect of noise on membrane excitability is not clear. In neurons, electrical membrane noise arises from different sources, such as the quasi-random release of neurotransmitters from the synapses and the random switching of ion channels [4, 6, 10] . Recently some experimental and computational studies have reported that channel noise can be a major contributor to electrical membrane noise in neurons, and stochastic behavior of the persistent sodium channel becomes a primary source of channel noise [4, 6, 11] . In addition, nonlinear systems with Abstract Noise can play a constructive role in the detection of weak signals in various kinds of peripheral receptors and neurons. What the mechanism underlying the effect of noise is remains unclear. Here, the perforated patch-clamp technique was used on isolated cells from chronic compression of the dorsal root ganglion (DRG) model. Our data provided new insight indicating that, under conditions without external signals, noise can enhance subthreshold oscillations, which was observed in a certain type of neurons with high-frequency (20-100 Hz) intrinsic resonance from injured DRG neurons. The occurrence of subthreshold oscillation considerably decreased the threshold potential for generating repetitive firing. The above effects of noise can be abolished by blocking the persistent sodium current ( I Na, P ). Utilizing a mathematical neuron model we further simulated the effect of noise on subthreshold oscillation and firing, and also found that noise can enhance the electrical activity through autonomous stochastic resonance. Accordingly, we propose a new concept of the effects of noise on neural intrinsic activity, which suggests that noise may be an important factor for modulating the excitability of neurons and generation of chronic pain signals.
doi:10.1159/000324519 pmid:21422753 fatcat:w3jhtywvjrbntdth2x7ddw4m4e