GHEIBI N, SEMNANIAN S, FATHOLLAHI Y. EFFECTS OF FORMALIN AS A PERIPHERAL NOXIOUS STIMULUS ON THE NUCLEUS RETICULARIS PARAGIGANTOCELLULARIS NEURONS OF ANESTHETIZED RATS. Med J Islam Repub Iran 2001; 15 (2) :109-114
URL:
http://mjiri.iums.ac.ir/article-1-813-en.html
From the Department of Medical Physics, Medical School, Qazvin University of Medical Sciences, Qazvin. The Department of Physiology, School of Medical Scences, Tarbiat Modarres University, Tehran. And the Institute of Biochemistry and Biophysics, Tehran University, Tehran, I.R.Iran.
Abstract: (3328 Views)
In the present study, the effects of formalin as a peripheral noxious stimulus
on spontaneously active units of the nucleus reticularis paragigantocellularis (PGi),
a narrow region of the ventral pontine reticular formation, was examined in urethane
anesthetized rats. Spontaneous discharge of the PGi neurons was variable,
ranging from I to 37 spikes per second. Formalin as a chemical irritant and prolonged
noxious stimulus induced changes in the firing of spontaneously active
PGi neurons. There were three neuronal subpopulations in the PGi that responded
to formalin: excited (19.35 %), inhibited (45.16 %) and unchanged (35.48 %).
Thus we suggest that PGi neurons may be involved in the processing of information
related to formalin as a chemical irritant.