Effects of Tooth-Pain on the Lateral Hypothalamus, the feeding center

采用电生理学和组织学方法研究了大鼠下丘脑外侧神经元对牙髓电刺激的反应和牙髓向LHA的感觉投射通路。1)在LHA的外侧部分发现对对侧下切牙髓刺激有反应的IIiA神经元，这些神经元也对密集的尾夹有反应，但对非葡萄糖的无害刺激没有反应。2) WGA-HRP在LHA外侧部感染后的组织学研究显示中脑脑室周围灰区（FVG）腹侧部有许多逆行标记的神经元。3) FVG神经元对LHA刺激和对侧下切牙髓刺激有相反的反应。4)将WGA-HRP注射到FVG的腹侧部分后，在三叉神经核（NTST）脊髓束对侧尾侧亚核中发现了许多标记细胞，这是以前报道的髓质传入神经终止的地方。因此，这表明FVG是最可能的从门牙到LHA的伤害性输入传递中继的位置。

The response of the rat lateral hypothalamic(LEA)neurons to tooth pulp electrical stimlation and the sensory projection pathway from the inusor pulp to the LHA were studied by electrophysiology and histology. 1)IIiA neurons that responded to contralateral lower incisor pulp stimulation were found in the lateral part of the LHA, These neurons also responded to intensive tail pinch, but not to innocuous stimuli nort appliedglucose. 2)Histological study after infection of WGA-HRP into the lateral part of the LHA revealed many retrogradely labeled neurons in the ventral part of the periventricular gray(FVG)in the mesencephalon. 3)The FVG neurons responded antidromically to LHA stimulation and-tb contralateral lower incisor pulp stimulation. 4)After injection of WGA-HRP into the ventral portion of the FVG many labeled cells were found in the contralateral subnucleus caudalis in the spinal tract of the trigeminal nucleus(NTST)where termination of the pulpal afferent was previously reported. It is thus suggested that the FVG is the most likely site of transmission relay of nociceptive inputs from incisors to the LHA.