Zhang Limei, Corona-Morales Aleph A, Vega-González Arturo, García-Estrada Joaquín, Escobar Alfonso
Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Neurosci Lett. 2009 Feb 6;450(3):242-5. doi: 10.1016/j.neulet.2008.12.007. Epub 2008 Dec 10.
We have previously reported that dietary tryptophan (TRP) restriction in a rat crucial postnatal developmental stage induces depression-like behavior and alters dendritic spine density in CA1 pyramidal neurons and granule cells of the hippocampus. Due to astrocyte involvement in critical brain mechanisms, it seems worth to investigate possible adaptive changes in the glial population with TRP restriction. Experimental rats were fed with low TRP diet (20% of TRP level of the laboratory rat chow) from postnatal days 30-60. Antibody against glial fibrillary acidic protein (GFAP), a principal intermediate filament in astrocytes, was used to evaluate cytoskeletal hypertrophy and glial proliferation. Our results showed an increase in size and branching of GFAP-immunoreactive (IR) cells in the dorsal hippocampus and amygdala, characteristics of an astrocytic activation. No significant differences were found regarding the number of GFAP-IR cells in both regions. These results indicate that dietary TRP restriction can induce astrocytic activation, hence, provide further evidences supporting the hypothesis that serotonin may also modulate glial morphology.
我们之前报道过，在大鼠关键的出生后发育阶段限制饮食中的色氨酸（TRP）会诱发类似抑郁的行为，并改变海马体CA1锥体神经元和颗粒细胞的树突棘密度。由于星形胶质细胞参与关键的脑机制，研究色氨酸限制时神经胶质细胞群可能的适应性变化似乎是值得的。从出生后第30天至60天，给实验大鼠喂食低色氨酸饮食（实验室大鼠食物中色氨酸水平的20%）。使用针对星形胶质细胞中主要中间丝的胶质纤维酸性蛋白（GFAP）的抗体来评估细胞骨架肥大和神经胶质细胞增殖。我们的结果显示，背侧海马体和杏仁核中GFAP免疫反应性（IR）细胞的大小和分支增加，这是星形胶质细胞激活的特征。在这两个区域中，GFAP-IR细胞的数量没有发现显著差异。这些结果表明，饮食中色氨酸限制可诱导星形胶质细胞激活，因此，为血清素也可能调节神经胶质细胞形态这一假说提供了进一步的证据。
