电刺激POAH对IL-1β作用下兔VSA温敏神经元放电的影响

目的和方法:为了从细胞水平进一步探讨发热时体温正、负调节中枢的调节机制,本实验采用微电极细胞外记录技术,在26只新西兰兔脑腹中隔区(ventralseptalarea,VSA)记录了温敏神经元单位放电,观察电刺激下丘脑视前区(preopticanteriorhypothalamus,POAH)对致热原IL-1_β作用下兔VSA温敏神经元放电的影响。结果:(1)侧脑室注射的白介素-1_β(IL-1_β)能使VSA热敏神经元放电频率增加,冷敏神经元放电减少,而侧脑室注射等量人工脑脊液(ACSF)对热敏神经元和冷敏神经元的放电均无明显影响。(2)电刺激POAH可反转致热原IL-1_β对VSA热敏神经元和冷敏神经元的上述作用。结论:在致热原作用下的体温调节中,正调节中枢POAH和负调节中枢VSA具有密切的相互作用。

Electrical stimulation of POAH alters firing rates of IL-1β-treated thermosensitive neurons in the VSA in rabbits

AIM and METHODS: To investigate the functional connection between the preoptic anterior hypothalamus (POAH) and the ventral septal area (VSA) in fever mechanism, the firing rates of thermosensitive neurons in the VSA of 26 New Zealand white rabbits were recorded using extracellular microelectrode technique. RESULTS: The firing rates in both types of thermosensitive neurons in the VSA had no significant changes after intracerebroventricular (icv) injection of artificial cerebrospinal fluid(ACSF). When interleukin-1_β (IL-1_β) was given (icv), the firing rate of the warm-sensitive neurons was increased significantly and that of the cold-sensitive neurons was decreased remarkably. The effects of IL-1_β on the changes of firing rate in thermosensitive neurons of the VSA were reversed by electrical stimulation of the POAH. CONCLUSION: The roles of positive and negative thermoregulatory centers in the interaction between the POAH and VSA are closely linked during endogenous pyrogen induced fever.