Piyabhan Pritsana, Wetchateng Thanitsara, Sireeratawong Seewaboon
Department of Preclinical Science, Faculty of Medicine, Thammasat University, Rangsit Campus, Pathumthani, Thailand.
J Med Assoc Thai. 2013 Feb;96(2):231-8.
Cognitive impairment is a common characteristic in schizophrenia that cannot be attenuated by antipsychotics. Brahmi, popularly known as a cognitive enhancer might be a new frontier of cognitive deficit treatment in schizophrenia.
To study effects of Brahmi on attenuation at cognitive deficit and cerebral glutamate/N-methyl-D-aspartate (NMDA) receptor density in sub-chronic phencyclidine (PCP) rat model of schizophrenia.
Rats were administered PCP or vehicle. Half of the PCP-group was treated with Brahmi. Discrimination ratio (DR) representing cognitive ability was obtained from novel object recognition task. NMDA immunodensity was measured in prefrontal cortex, striatum, cornu ammonis fields 1 to 3 of hippocampus (CA1-3), and dentate gyrus (DG) using immunohistochemistry.
DR in PCP-group was significantly decreased compared with control. This occurred alongside NMDA up-regulation in prefrontal cortex and CA1-3, but not in striatum and DG. PCP with Brahmi showed a significant increase in DR score compared with PCP alone. This occurred alongside significant decrease in NMDA immunodensity in prefrontal cortex and CA1-3. No significant difference in cerebral NMDA immunodensity was observed between PCP with Brahmi and control.
Cognitive deficit observed in PCP-administered rats was mediated by NMDA up-regulation in prefrontal cortex and CA1-3. Interestingly, Brahmi could recover this cognitive deficit by decreasing NMDA density in these brain areas to normal.
认知障碍是精神分裂症的常见特征，抗精神病药物无法减轻这种症状。水龙骨俗称一种认知增强剂，可能是精神分裂症认知缺陷治疗的新前沿。
研究水龙骨对精神分裂症亚慢性苯环己哌啶（PCP）大鼠模型认知缺陷和脑谷氨酸/N-甲基-D-天冬氨酸（NMDA）受体密度的改善作用。
给大鼠注射PCP或赋形剂。PCP组的一半大鼠接受水龙骨治疗。通过新颖物体识别任务获得代表认知能力的辨别率（DR）。采用免疫组织化学法测量前额叶皮质、纹状体、海马1至3角（CA1-3）和齿状回（DG）中的NMDA免疫密度。
与对照组相比，PCP组的DR显著降低。这伴随着前额叶皮质和CA1-3中NMDA上调，但纹状体和DG中未出现这种情况。与单独使用PCP相比，PCP与水龙骨联合使用时DR评分显著增加。这伴随着前额叶皮质和CA1-3中NMDA免疫密度显著降低。PCP与水龙骨联合使用组和对照组之间脑NMDA免疫密度未观察到显著差异。
PCP给药大鼠中观察到的认知缺陷是由前额叶皮质和CA1-3中NMDA上调介导的。有趣的是，水龙骨可以通过将这些脑区的NMDA密度降低至正常水平来恢复这种认知缺陷。
