Fernández-Guardiola A, Pellicer F, León-Olea M, Asai M, Sánchez-Alvarez M
Instituto Mexicano de Psiquiatría, División de Investigaciones en Neurociencias, México.
Neuropeptides. 1989 Aug-Sep;14(2):115-20. doi: 10.1016/0143-4179(89)90068-1.
The sustained inhibitory action of spinal endorphins could be responsible for the habituation of polysynaptic responses in the spinal cord. To test this hypothesis, acute spinalized unanesthetized cats (decerebrated and curarized) were used. Sural nerve electrical stimulation (0.2 Hz) was provided and a progressive decrease in the reflex response was found. Conversely, the field potential (lamina V) progressively increased during stimulation, reaching its maximum amplitude when ventral root response showed maximum habituation. The administration of naloxone (0.8-10.0 mg/kg) produced dehabituation or prevented habituation. The immunohistological results showed leu-enkephalin-like immunoreactive dot-like structures in close proximity to neurons of laminae VII, VIII and IX in the lumbo-sacral segment of the spinal cord. Our results suggest an involvement of opioid peptides in the habituation process.
脊髓内啡肽的持续抑制作用可能是脊髓多突触反应产生习惯化的原因。为验证这一假说，使用了急性脊髓横断且未麻醉的猫（去大脑并使用箭毒）。给予腓肠神经电刺激（0.2赫兹），发现反射反应逐渐减弱。相反，在刺激过程中，V层的场电位逐渐升高，当腹根反应出现最大程度的习惯化时，场电位达到最大振幅。注射纳洛酮（0.8 - 10.0毫克/千克）可使习惯化消失或防止习惯化的产生。免疫组织学结果显示，在脊髓腰骶段VII、VIII和IX层神经元附近存在亮脑啡肽样免疫反应性点状结构。我们的结果提示阿片肽参与了习惯化过程。
