PARAVENTRICULAR HYPOTHALAMIC CONTROL OF AUTONOMIC NEURON

下丘脑在调节正常动脉压中的重要性 这是经过多次调查确定的。 最近的研究 暗示下丘脑神经元功能的改变， 高血压 然而，下丘脑控制的精确性质， 动脉压尚未明确确定。 的最新进展 神经解剖追踪技术表明室旁核 (PVN)可能在中枢心血管调节中发挥重要作用， 向下投射到髓质和脊髓。 这些措施包括， 其中，单突触投射到（1）中间外侧细胞 柱（IML），脊髓中节前交感神经元的部位 脊髓，（2）迷走神经背侧运动核（DMNV），和（3）核 孤束（NTS），初级心血管传入部位 终止 目标是开始神经生理学和 下行投射功能的药理学描述 PVN在控制动脉压中的作用， 神经生理学技术 初步研究将描述 刺激和毁损PVN对动脉血压和心脏的影响 率在大鼠。 为了进一步了解这个系统，PVN的影响 刺激识别的IML、DMNV和NTS神经元的活性 将检查显示推定的心血管相关活性的细胞。 这些 实验将结合微注射和微压力 应用推定的神经递质怀疑包括 PVN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 向下投射到髓质和脊髓。 细胞内 将进行记录研究以阐明突触后效应 这些递质和突触输入的性质，从PVN的细胞， 这些地区。 本研究和后续研究的目的是 阐明下丘脑投射对交感神经和 副交感神经节前神经元和其他涉及的髓质神经元 中枢神经对动脉压的调节

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.