Merchan-Perez A, Gil-Loyzaga P, Eybalin M
Laboratoire de Neurobiologie de l'Audition, INSERM U. 254, CHR St. Charles, Montpellier, France.
Eur Arch Otorhinolaryngol. 1990;248(1):4-7. doi: 10.1007/BF00634770.
gamma-Aminobutyric acid (GABA)-ergic efferent nerve fibers were studied during the postnatal development of the rat cochlea, using light microscopic immunocytochemical techniques. Antibodies against GABA and its synthesizing enzyme, glutamate decarboxylase (GAD), were used. Immunoreactivity to GAD is already present at birth (postnatal day 1) and could be found below the inner hair cells of the basal turn. Immunoreactivity progressively extends toward the apical turn until day 3. GAD-like immunoreactivity appears under the outer hair cells on postnatal day 15 and is only found in the upper part of the second turn and in the apical turn. The distribution of GABA-like immunoreactivity closely corresponds to that observed with the anti-glutamate decarboxylase antibody. However, the GABA-like immunoreactivity appears about 1-2 days after GAD-like immunoreactivity. At the beginning of the 3rd postnatal week, an adult pattern of GABA- and GAD-like immunoreactivity is established. These results suggest that GABA, which appears under the inner hair cells largely before the onset of hearing, may play a neurotrophic function during cochlear maturation and participate in the regulation of the first cochlear potentials as soon as they appear.
利用光学显微镜免疫细胞化学技术，对大鼠耳蜗出生后发育过程中的γ-氨基丁酸（GABA）能传出神经纤维进行了研究。使用了抗GABA及其合成酶谷氨酸脱羧酶（GAD）的抗体。出生时（出生后第1天）即可检测到对GAD的免疫反应性，且在蜗底内毛细胞下方可见。到第3天时，免疫反应性逐渐向蜗顶延伸。出生后第15天，在外毛细胞下方出现GAD样免疫反应性，且仅在第二圈上部和蜗顶可见。GABA样免疫反应性的分布与抗谷氨酸脱羧酶抗体所观察到的分布密切对应。然而，GABA样免疫反应性比GAD样免疫反应性出现约晚1 - 2天。在出生后第3周初，建立了GABA和GAD样免疫反应性的成年模式。这些结果表明，在听力开始之前，大部分出现在内毛细胞下方的GABA可能在耳蜗成熟过程中发挥神经营养功能，并在耳蜗电位一出现时就参与其调节。
