Effects of Electroacupuncture with Different Frequencies on the Spinal c-fos and Inotropic Glutamate Receptor Expression in Carrageenan-injected Rat / 체질인류학회지

ABSTRACT

We investigated the comparative effects of electroacupuncture (EA) with different frequency on the spinal c-fos and inotropic glutamate receptor expression in carrageenan-injected rats. Bilateral EA stimulation with 2, 15 and 120 Hz were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles. The inhibitory effects of the EA on the inflammatory process were investigated in the central nociceptive sites by immunohistochemical analysis. Three hours after carrageenan injection, the number of c-fos-like immunoreactive (LI) neurons was significantly increased in all layers of the ipsilateral spinal cord at L4-5 segment. But these immunoreactive neurons were markedly reduced in the spinal gray matter, especially in the superficial laminae, by all kinds of EA stimulation. The number of NMDA (NR-1 and NR-2A) and AMPA receptors (GluR-1, GluR-2/3) -LI neurons was also increased by carrageenan injection. But NR-2A-LI neuron was significantly reduced in superficial laminae of dorsal horn by 2 Hz EA stimulation. While GluR-1-LI neuron of 15 Hz and 120 Hz EA was increased in the nucleus proprius compared with carrageenan-injected group, GluR-2/3-LI neuron of these EA stimulated groups significantly reduced in superficial laminae of dorsal horn. In conclusion, EA treatment can attenuate spinal c-fos expression in carrageenan injected rats and regulates spinal inotropic glutamate receptor expression.