IDENTIFICATION OF MIDBRAIN NEURONS MEDIATING DEFENSIVE BEHAVIOR IN THE RAT BY MICROINJECTIONS OF EXCITATORY AMINO-ACIDS
IDENTIFICATION OF MIDBRAIN NEURONS MEDIATING DEFENSIVE BEHAVIOR IN THE RAT BY MICROINJECTIONS OF EXCITATORY AMINO-ACIDS
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DOI：
10.1016/0166-4328(85)90058-0
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发表时间：
1985-01-01
影响因子：
2.7
通讯作者：
VERGNES, M
中科院分区：
文献类型：
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作者：
BANDLER, R;DEPAULIS, A;VERGNES, M
将兴奋性氨基酸单侧微量注射（0.20 μ l）到自由活动大鼠的中脑中。在中脑导水管周围灰质（PAG）内进行的注射一致地引起防御行为特征的反应（即，爆发性跳跃、冻结、直立姿势），而在毗邻PAG的被盖中进行的注射并不可靠地引起这种行为。由于兴奋性氨基酸的注射使细胞体而不是轴突退化，因此主要在大鼠的中脑PAG内发现其兴奋激发这些反应的神经元群体。这些神经元可能优先位于中脑PAG的尾侧半部分。在许多相同的中脑部位注射GABA拮抗剂甲碘荷包牡丹碱，产生的行为与兴奋性氨基酸引起的行为相似，表明这些相同的PAG介导的反应可能存在GABA能调节。单侧注射到PAG后，无论是兴奋性氨基酸，L-天冬氨酸或荷包牡丹碱，防御行为引起触摸大鼠的身体或口鼻部对侧，但不同侧的注射部位。单侧PAG刺激诱导防御行为至少部分是由于感觉运动反应性的偏侧改变。
Unilateral microinjections (0.20 .mu.l) of excitatory amino acids were made into the midbrain of freely moving rats. Injections made within the midbrain periaqueductal grey matter (PAG) consistently elicited reactions characteristic of defensive behavior (i.e., explosive jumps, freezing, upright postures), whereas injections made in the tegmentum bordering the PAG did not as reliably elicit such behavior. As injections of excitatory amino acids depolarize cell bodies but not axons, a population of neurons whose excitation elicits these reactions is found primarily within the midbrain PAG of the rat. Such neurons may be localized preferentially within the caudal half of the midbrain PAG. Injections of the GABA antagonist, bicuculline methiodide, at many of the same midbrain sites produced behavior similar to that elicited by excitatory amino acids indicating a possible GABAergic modulation of these same PAG-mediated reactions. Following unilateral injection into the PAG, of either the excitatory amino acid, L-aspartic acid or bicuculline, defensive behavior was elicited by touching the rat on the body or snout contralateral but not ipsilateral to the injection site. The induction of defensive behavior by unilateral PAG stimulation is due, at least in part, to lateralized alterations in sensorimotor responsiveness.