【摘要】 为了确定丘脑束旁核神经元对外周神经伤害性刺激的各类反应是否都属于痛敏反应,在氯醛糖麻醉的36只猫上观察了束旁核神经元对强电流刺激外周神经与动脉注射缓激肽的放电反应。根据放电的潜伏期和持续时间,可将观察到的162个单位对强电流刺激外周神经的反应分成四种类型。1.短潜伏期反应,69个单位。2.长潜伏期反应,15个单位。3.短-长潜伏期反应,37个单位。4.自发放电抑制,41个单位。静脉注射芬太尼不能抑制短潜伏期反应,动脉注射缓激肽不能诱发这类神经元放电,说明这类反应不是痛敏反应。其它三种反应,都可为静脉注射芬太尼所抑制或减弱,又可为动脉注射缓激肽所诱发,说明这三类反应都属于痛敏反应。更多还原

【Abstract】 Responses of neurons in parafascicular nucleus of thalamus (Pf) to noxiousstimulation of cutaneous (sural) nerve and deep (gastrocnemius) nerve as well asto injection of Bradykinin (BK) into gastrocnemius artery were studied in 36 catsanesthetized with chloralose. 162 units were studied, among which 143 units (88.3%) were found to respondto both sural and gastrocnemius nerve stimulation, while the other 19 units (11.7%)only to gastrocnemius stimulation. According to the pattern of discharges andlatencies of the responses, Pf neurons could be classified into 4 types: (1) 69 unitsresponded to nerve stimulation with short latency(usually 20--40 ms) discharges.Administration of Fentanyl (30μg/kg, i.v.) did not affect the responses and BK(20μg/kg, i.v.) did not evoke discharges in all 7 units tested. (2) 15 units hadlatencies longer than 100 ms. (3) The responses of 37 units started with an earlyshort burst of discharges followed by a late long and lasting firing with long latency.(4) The spontaneous discharges of 41 units were inhibited by stimulation of theperipheral nerves. Fentanyl (30μg/kg, i.v.) remarkably suppressed the long latencydischarges of type 3 neurons and abolished the inhibitory responses of thespontaneous discharges of type 4 neurons evoked by noxious stimulation. BK(20μg/kg, i.a.) could excite both type 2 and 3 neurons and inhibited thespontaneous discharges of type 4 neurons. It is concluded that all types of the Pf neurons, except type 1, might be regardedas nociceptive, in which either excitatory or inhibitory responses could be producedby noxious stimulation.更多还原