1 Neuroscience Research Institute, Peking University, Beijing 100191, China 
2 Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China 
3 Key Laboratory for Neuroscience, the Ministry of Education / the Ministry of Health, Peking University, Beijing 100191, China

Abstract 

Objective
The present study aimed to investigate the electrophysiological properties of wide dynamic range (WDR) neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 (L5) spinal nerve ligation (SNL) in a large size of samples.
Methods
Adult Sprague-Dawley rats were divided into normal and SNL groups. Electrophysiological technique was used to record the characteristics of WDR neurons in the spinal dorsal horn.
Results
Compared with the WDR neurons in normal rats, the WDR neurons in SNL rats showed an increase in excitability, manifested by an enlargement of the receptive field size, an increase in the proportion of neurons that exhibited spontaneous activities, decreases in the C-response threshold and latency, and an increase in the C-response duration. In addition, the numbers of Aβ- and C-fiber-evoked discharges were smaller in SNL rats than in normal rats.
Conclusion
The excitability of spinal WDR neurons increased in rats with neuropathic pain induced by L5 SNL. The increase in excitability of WDR neurons may contribute to the development of neuropathic pain.

Keywords

wide dynamic range neuron; spinal dorsal horn; spinal nerve ligation; neuropathic pain

[SpringerLink]