Yang Q Z, Hatton G I
Department of Neuroscience, University of California, Riverside 92521, USA.
Brain Res. 1997 Oct 31;773(1-2):162-72. doi: 10.1016/s0006-8993(97)00932-3.
Anatomical evidence exists for projections to the tuberomammillary nucleus (TM) from the nucleus of the diagonal band of Broca (DBB) and the lateral preoptic area (LPO). The physiological effects of activating these inputs were studied by recording postsynaptic responses intracellularly from TM cells during both electrical stimulation and local nanodrop application of glutamate in horizontally cut brain slices. Electrical stimulation of the DBB, LPO and anterior lateral hypothalamic area (LH) usually evoked fast IPSPs (approximately 75% of responses) which were blocked by bicuculline or picrotoxin, suggesting GABA(A) mediation. The remaining excitatory responses evoked by stimulation of the LPO and LH were blocked by non-NMDA receptor antagonists (CNQX or NBQX) and the NMDA receptor antagonist, AP-5. Glutamate applied to the above areas induced postsynaptic responses in TM cells similar to those seen with electrical stimulation. Spontaneous firing in TM cells was suppressed by glutamate applied in the DBB. Glutamate applied in the LPO or LH evoked both inhibitory and excitatory responses. Changes in PSPs and firing rates were interpreted to result from glutamate activation of the neurons in the DBB, LPO and LH areas with inhibitory or excitatory connections to recorded TM neurons. These results support previous anatomical findings and suggest that inhibitory and excitatory synaptic control of TM activity is exerted by the DBB, LPO and LH areas.
存在从布罗卡斜角带核（DBB）和外侧视前区（LPO）向结节乳头体核（TM）投射的解剖学证据。通过在水平切割的脑片中对TM细胞进行细胞内记录突触后反应，研究了激活这些输入的生理效应，记录过程中分别进行了电刺激和局部微量滴注谷氨酸。对DBB、LPO和下丘脑外侧前区（LH）的电刺激通常诱发快速抑制性突触后电位（IPSPs，约75%的反应），这些电位被荷包牡丹碱或印防己毒素阻断，提示由GABA(A)介导。刺激LPO和LH所诱发的其余兴奋性反应被非NMDA受体拮抗剂（CNQX或NBQX）和NMDA受体拮抗剂AP-5阻断。向上述区域施加谷氨酸可在TM细胞中诱发类似于电刺激所见的突触后反应。在DBB中施加谷氨酸可抑制TM细胞的自发放电。在LPO或LH中施加谷氨酸可诱发抑制性和兴奋性反应。对突触后电位和放电频率变化的解释是，DBB、LPO和LH区域的神经元被谷氨酸激活，这些神经元与记录的TM神经元存在抑制性或兴奋性联系。这些结果支持了先前的解剖学发现，并表明TM活动的抑制性和兴奋性突触控制是由DBB、LPO和LH区域施加的。
