Rose J D, Havens M D
Brain Res Bull. 1986 Jan;16(1):39-45. doi: 10.1016/0361-9230(86)90010-9.
Previous research has shown that bilateral deep tectal lesions in golden hamsters abolish the lordosis response, whereas unilateral lesions selectively impair lordosis elicitation by contralateral flank stimulation. The present study analyzed the neural basis of these lesion effects by assessing the somatosensory responsiveness of midbrain neurons in three groups of urethane-anesthetized hamsters: animals with lordosis-abolishing bilateral tectal lesions, animals with lordosis-impairing unilateral lesions, and intact animals. Animals with bilateral lesions differed from the other groups in three aspects of unit sensory responsiveness by showing: (1) the highest percentage of neurons responsive to somatic stimulation, (2) the highest incidence of unit responsiveness to flank stimulation, and (3) the greatest proportion of responsive neurons in the ventral tegmentum. Hamsters with unilateral lesions showed basically normal unit responsiveness apart from elevated unit response to face stimulation. The results suggest that bilateral tectal lesions may eliminate lordosis by the combined effects of enhanced ventral tegmental somatosensory responsiveness and tectal destruction. Unilateral lesions appear to impair lordosis without changing the somatosensory excitability of remaining midbrain neurons.
先前的研究表明，金黄仓鼠双侧深部顶盖损伤会消除脊柱前凸反应，而单侧损伤会选择性地损害对侧胁腹刺激引起的脊柱前凸。本研究通过评估三组经乌拉坦麻醉的仓鼠中脑神经元的体感反应性，分析了这些损伤效应的神经基础：具有消除脊柱前凸反应的双侧顶盖损伤的动物、具有损害脊柱前凸反应的单侧损伤的动物以及完整无损的动物。双侧损伤的动物在单位感觉反应性的三个方面与其他组不同，表现为：（1）对躯体刺激有反应的神经元比例最高，（2）对胁腹刺激的单位反应发生率最高，（3）腹侧被盖区反应性神经元的比例最大。除了对面部刺激的单位反应增强外，单侧损伤的仓鼠表现出基本正常的单位反应性。结果表明，双侧顶盖损伤可能通过增强腹侧被盖区体感反应性和顶盖破坏的联合作用来消除脊柱前凸。单侧损伤似乎在不改变其余中脑神经元体感兴奋性的情况下损害脊柱前凸。
