红核的镇痛作用及其机制的初步探讨

<正> 传统的观念认为,红核的主要机能是调节躯体运动和肌紧张。但近年来有少量工作提示,红核与感觉的调制也有关。我们以往的工作证明,兴奋大鼠红核可使引起甩尾反

The analgesic effect of red nucleus and preliminary research on its mechanism]

The spontaneous discharges of neurons in red nucleus (RN) of rats have been recorded with microelectrode. The discharge frequency of most RN neurons was changed by nociceptive electrical stimulation of nervi peronaeus communis or nervi tibialis or by nociceptive mechanical stimulation of tail or hind leg. The electrical activities of the somatic sensory neurons in the nucleus ventralis posterolateralis (VPL) of thalamus and of the visceral sensory neurons in the nucleus anterior and nucleus parafascicularis of thalamus have been recorded. According to the form of response to the peripheral nociceptive stimulation the neurons concerned could be divided into three types: pain-excited, pain-inhibited and pain-nonrelated. Electrical stimulating RN could change the spontaneous discharge frequency of somatic pain-related neurons of VPL and visceral pain-related neurons of nucleus anterior and nucleus parafascicularis, and could inhibit their response to somatic and visceral nociceptive stimulation respectively, but did not have influence on the activity of most pain-nonrelated neurons in VPL. The effects of electrical stimulating RN and microinjecting Ach into RN on the same pain-related neuron in VPL were similar. The experimental results show that RN can receive the somatic afferent impulses, that the excited RN can inhibit the transmission of somatic and visceral nociceptive impulses into the thalamus, and that the analgesic effect of RN is concerned with Ach.