ABSTRACT
Objective To study the effect of intracerebroventricular(icv) injectionon acetylcholine(ACh) on the elecric activities of pain-related neurons in the hippocampal CA1 area of rat.Methods Trains of the electric impulses applied to the right sciatic nerve were used as noxious stimuli.The discharges of neurons were led out by extracellular recording method with glass microelectrodes.Results Icv injection of ACh(20?g/10?l) caused an decrease of the evoked discharge frequency of pain-excited neurons(PEN) and a prolongation latency as well as an increase of the evoked discharge of pain-inhibited neurons(PIN) and a shortening of inhibitory duration.Conclusion The response of pain-related neurons in hippocampal CA1 area to the noxious stimulation is weakened by icv injection of ACh,exhibiting analgesic effect.
ABSTRACT
Aim To investigate the effects of cholecys-tokinin octapeptide(CCK-8)on the withdrawal symp-toms of morphinistic rats by the observation of praxiology,and change of expression of proto-oncogene c-jun in caudate nucleus(Cd) after CCK-8 injected by immunohistochemistry.Methods Animal praxiology evaluation and immunohistochemistry were used.The influence of CCK-8(10 mg?L-1,1 ?l) on the withdrawal symptoms and the expression of c-jun of morphinistic rats was observed.Results Morphinistic rats had obvious praxiological changes in the withdrawal symptoms compared with normal saline rats;the scores of withdrawal symptoms decreased most obviously at withdrawal 40 h after Cd injection of CCK-8;the expression of c-jun protein in Cd decreased in morphinistic rats,but increased after Cd injection of CCK-8.Conclusions Models of morphinomania rats were successfully built.The Cd injection of CCK-8 could decrease the withdrawal symptoms of morphinomania rats.The CCK-8 could increase the expression of c-jun protein in Cd.These findings suggested that CCK-8 could regulate the production of withdrawal symptoms and the expression of c-jun protein in Cd of morphinomania rats.
ABSTRACT
Aim To observe the effect of dopamine (DA) and its antagonist on the electrical activities of pain excitation neurons (PEN) in the caudate nucleus (Cd) of morphine dependent rats. Methods The right sciatic nerve was stimulated by train of electrical impulses as noxious stimuli to morphine dependent rats.The electrical discharges of PEN in Cd were recorded with glass microelectrode to observe influences of intracerebroventricular (icv) injection of DA and droperidol on the electrical activities of PEN. Results DA could decrease excitabilities of PEN in Cd of morphine dependent rats. Conclusion Results suggest that the depression of DA on PEN response in Cd of morphine dependent rats might be blocked by droperidol.