Effects of midazolam on the response of parafascicular nucleus to noxious stimuli
- VernacularTitle:咪唑安定对大鼠丘脑束旁核感受伤害性刺激神经元的干预反应研究
- Author:
Dajiang WAN
;
Zheng GUO
- Publication Type:Journal Article
- Keywords:
Midazolam;
Pararentricular hypothalamic nucleus;
Neurons;
Electrophysiology
- From:
Chinese Journal of Anesthesiology
1994;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of intravenous midazolam on the response of parafascicular nucleus(Pf) to noxious stimuli in rats. Methods Twenty SD rats of both sexes weighing 260-300g were used in the study. The animals were anesthetized with intraperitoneal urethane(1.2 g/kg) . A hole was drilled in the skull. Under stereomicroscope micro-glass electrode was inserted into Pf nucleus and the characteristic discharge of nociceptive neurons was recorded. The experiment was then performed in four steps. The discharge was recorded in the basal state (A), when hind paw was pinched by a pair of strong forceps: noxious stimuli (B) , 2 min after midazolam 0.2 mg/kg was given intravenously , step B was repeated (C) and flumazenil 0.05mg was given iv and 2 min later step B was repeated (D) . There was a pause of 5 min after each step. Results The characteristic discharge of nociceptive neurons was recorded only in 9 animals and the data from 6 animals were complete and could be analyzed. Noxious stimuli induced significant increase in spike of discharge of nociceptive neurons. Midazolam significantly depressed the response of nociceptive neurons to noxious stimuli. There was no significant difference in the mean spikes of discharge of nociceptive neurons between step A and C. After flumazenil the mean spike of discharge increased again in response to noxious stimuli. Conclusion Midazolam can inhibit the activity of the nociceptive neurons located in Pf nucleus, probably through GABA-BZ receptor.
