[Effect of chaotic and periodic sympathetic nerve stimulation on the activity of chronically compressed rat dorsal root ganglion neurons].
OBJECTIVE
To study the responses of injured dorsal root ganglion (DRG) neurons to sympathetic nerve stimulation with different time sequences.


METHODS
In chronically compressed DRG model, the spontaneous activity of the single fiber from injured DRG neurons was recorded, and the responses of DRG neurons to chaotic and periodic electric stimulation of the lumbar sympathetic trunk compared.


RESULTS
Sympathetic-sensory coupling was present in chronically compressed DRG neurons, and the response of DRG neurons increased gradually as the sympathetic stimulating frequency increased from 5 to 20 Hz (P<0.01). The chaotic stimulation evoked much greater response than periodic stimulation, even though the stimulating frequency was similar (P<0.01).


CONCLUSIONS
Besides the stimulating frequency, the time sequence of the stimulation is one of the important factors that influence the response of DRG neurons to sympathetic stimulation. Chaotic sympathetic stimulation causes greater response than periodic stimulation does, and the chaotic activity of presynaptic neuron evokes greater postsynaptic response than periodic activity. The chaotic activity of the neurons might be one of the effective ways for information transmission through the nerves.
Yang
Hong-jun
HJ
Department of Neurology, Guangzhou General Hospital of Guangzhou Command, Guangzhou 510010, China. yanghongjun66om66@yahoo.com.cn
Hu
San-jue
SJ
D000818:Animals; D004558:Electric Stimulation; D005260:Female; D005727:Ganglia, Spinal / Q000503:physiopathology*; D008297:Male; D009408:Nerve Compression Syndromes / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000502:physiology*