PARAVENTRICULAR HYPOTHALAMIC CONTROL OF AUTONOMIC NEURON

下丘脑在调节正常动脉压中的重要性 已经通过多项调查得到了证实。最近的研究表明 牵涉到某些形式的下丘脑神经功能改变 高血压。然而，精确的下丘脑控制的本质 动脉压还没有得到明确的确定。的最新进展 神经解剖示踪技术表明，室旁核 下丘脑室旁核可能通过以下途径在中枢心血管调节中发挥重要作用 向下投射至延髓和脊髓。这些措施包括： 其中，单突触投射到(1)中间外侧细胞 节前交感神经元在脊髓内的位置 脊髓，(2)迷走神经背侧运动核(DMNV)，和(3)核 孤束(NTS)--初级心血管传入的部位 终止。我们的目标是开始一个神经生理学和 下丘脑下行投射功能的药理学描述 PVN在控制动脉血压中的应用 神经生理学技术。初步研究将确定 刺激和损毁室旁核对动脉压和心脏的影响 在大鼠中的比率。为了进一步了解这一系统，PVN的影响 刺激已鉴定的IML、DMNV和NTS神经元的活动 将检查是否有可能与心血管相关的活动。这些 实验将与微量注射和微压相结合 疑似神经递质在临床上的应用 下丘脑室旁核下行通路，特别是加压素和催产素。 这两个发射器被认为构成了 向下投射至延髓和脊髓。细胞内 将进行录音研究以阐明突触后的影响 这些递质的性质以及从PVN到细胞的突触输入的性质 这些区域。这项研究和后续研究的目标是 阐明下丘脑投射对交感神经和 副交感节前神经元和其他延髓神经元受累 中枢神经对动脉压的调节作用。

The importance of the hypothalamus in regulating normal arterial pressure has been established by a number of investigations. Recent studies have implicated altered hypothalamic neuronal function in some forms of hypertension. However, the precise nature of hypothalamic control of arterial pressure has not been clearly established. Recent advances in neuroanatomical tracing techniques suggest that the paraventricular nucleus (PVN) may play a major role in central cardiovascular regulation through descending projections to the medulla and spinal cord. These include, among others, mono-synaptic projections to (1) the intermediolateral cell column (IML), the site of preganglionic sympathetic neurons in the spinal cord, (2) the dorsal motor nucleus of the vagus (DMNV), and (3) the nucleus tractus solitarius (NTS), the site of primary cardiovascular afferent termination. The objectives are to begin a neurophysiological and pharmacological description of the function of descending projections from the PVN in controlling arterial pressure by using several neurophysiological techniques. Initial studies will characterize the effects of stimulation and lesion of the PVN on arterial pressure and heart rate in rats. To further understand this system, the influence of PVN stimulation on the activity of identified IML, DMNV, and NTS neurons showing putative cardiovascular-related activity will be examined. These experiments will be combined with the microinjections and micropressure application of putative neurotransmitters suspected to comprise the descending pathways from the PVN, particularly vasopressin and oxytocin. These two transmitters are thought to comprise a major portion of the descending projections to the medulla and spinal cord. Intracellular recording studies will be conducted to elucidate the postsynaptic effects of these transmitters and the nature of synaptic input from PVN to cells in these regions. The objective of this and succeeding studies is to elucidate the effects of hypothalamic projections upon sympathetic and parasympathetic preganglionic neurons, and other medullary neurons involved in central neural regulation of arterial pressure.