Stein P S, Schild C P
Department of Biology, Washington University, St. Louis, MO 63130.
Brain Res. 1989 Feb 13;479(2):379-83. doi: 10.1016/0006-8993(89)91645-4.
APV (D(-)-2-amino-5-phosphonovalerate), an NMDA (N-methyl-D-aspartate) antagonist, was applied in situ onto segments of the hindlimb enlargement of the turtle spinal cord. APV reduced the response amplitude of the flexion reflex. In contrast, APV did not alter the responsiveness of the rostral scratch reflex. Afferents for the flexion reflex enter the spinal cord via the dorsal roots of the middle segment of the hindlimb enlargement; afferents for the rostral scratch reflex enter the spinal cord via dorsal roots located anterior to the hindlimb enlargement. The results are consistent with the hypothesis that sensory interneuron NMDA receptors, synaptically activated either directly or indirectly by nearby cutaneous afferent axons, play a role in the spinal cord processing of cutaneous information.
APV（D-（-）-2-氨基-5-磷酸缬氨酸），一种NMDA（N-甲基-D-天冬氨酸）拮抗剂，被原位应用于龟脊髓后肢膨大节段。APV降低了屈肌反射的反应幅度。相比之下，APV并未改变吻侧搔抓反射的反应性。屈肌反射的传入神经通过后肢膨大中间节段的背根进入脊髓；吻侧搔抓反射的传入神经通过位于后肢膨大前方的背根进入脊髓。这些结果与以下假设一致：感觉中间神经元NMDA受体，由附近皮肤传入轴突直接或间接突触激活，在脊髓对皮肤信息的处理中起作用。
