Rowan S, Todd A J, Spike R C
Department of Anatomy, University of Glasgow, U.K.
Neuroscience. 1993 Mar;53(2):537-45. doi: 10.1016/0306-4522(93)90218-5.
In order to determine whether or not neuropeptide Y coexists with GABA or glycine in rat dorsal horn, we have examined 84 neuropeptide Y-immunoreactive neurons in laminae I-III with a combined pre- and postembedding immunocytochemical method. All of the neuropeptide Y-immuno-reactive neurons were also GABA-immunoreactive, but they were either non-immunoreactive or weakly immunoreactive with the glycine antiserum. In addition, a double-label immunofluorescence method was used to search for co-localization of neuropeptide Y and [Met]enkephalin in spinal cord. Although the two types of peptide immunoreactivity often coexisted in varicosities around the central canal and in the ventral horn, such coexistence was not seen in the superficial dorsal horn. These results suggest that neuropeptide Y is present in GABAergic neurons in laminae I-III of rat dorsal horn, but that it is largely or completely restricted to those neurons which do not contain glycine. In addition, the cells that contain GABA and neuropeptide Y appear to form a different population from those that contain GABA and [Met]enkephalin. Neuropeptide Y administered by intrathecal injection causes analgesia, and there is evidence that this may involve a presynaptic mechanism. The results of the present study suggest that neuropeptide Y may act in conjunction with GABA to produce presynaptic inhibition of nociceptive primary afferents.
为了确定神经肽Y是否与γ-氨基丁酸（GABA）或甘氨酸在大鼠背角中共存，我们采用包埋前和包埋后免疫细胞化学联合方法，检查了I-III层中的84个神经肽Y免疫反应性神经元。所有神经肽Y免疫反应性神经元也都是GABA免疫反应性的，但它们对甘氨酸抗血清要么无免疫反应，要么免疫反应较弱。此外，使用双标记免疫荧光法来寻找神经肽Y和[甲硫氨酸]脑啡肽在脊髓中的共定位。虽然这两种肽免疫反应性常常在中央管周围和腹角的曲张体中共存，但在背角浅层未见这种共存情况。这些结果表明，神经肽Y存在于大鼠背角I-III层的GABA能神经元中，但在很大程度上或完全局限于那些不含甘氨酸的神经元。此外，含有GABA和神经肽Y的细胞似乎与含有GABA和[甲硫氨酸]脑啡肽的细胞形成不同的群体。鞘内注射神经肽Y可产生镇痛作用，并且有证据表明这可能涉及一种突触前机制。本研究结果提示，神经肽Y可能与GABA共同作用，对伤害性初级传入纤维产生突触前抑制。
