TY - JOUR JF - MJIRI JO - Med J Islam Repub Iran VL - 15 IS - 2 PY - 2001 Y1 - 2001/8/01 TI - EFFECTS OF FORMALIN AS A PERIPHERAL NOXIOUS STIMULUS ON THE NUCLEUS RETICULARIS PARAGIGANTOCELLULARIS NEURONS OF ANESTHETIZED RATS TT - N2 - 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. SP - 109 EP - 114 AU - GHEIBI, N AU - SEMNANIAN, S AU - FATHOLLAHI, Y AD - 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. KW - Nucleus reticularis paragigantocellularis: Formalin: Single-unit recording. UR - http://mjiri.iums.ac.ir/article-1-813-en.html ER -