Pengaruh Stres Kronik terhadap Otak: Kajian Biomolekuler Hormon Glukokortikoid dan Regulasi Brain-Derived Neurotrophic Factor (BDNF) Pascastres di Cerebellum

Abstract

The brain is the central organ of stress adaptation, and is also a target of stress. Chronic stress may result in abnormal
changes in brain plasticity; include dendritic retraction, neuronal toxicity, and suppression of neurogenesis and
axospinous synaptic plasticity. Repetitive stress exposure will gradually change the electrical characteristic, morphology
and proliferative capacity of neurons. Among brain region, the cerebellum is known to be severely affected by oxidative
damage associated with glucocorticoids level. It is believed due to the highest levels of glucocorticoid receptors
localized in the external granular layer. BDNF, a member of neurotrophin family, is known to be a strong survival
promoting factor, and plays a critical role in cell proliferation and differentiation, neuronal protection, and the regulation
of synaptic function in the central nervous system. BDNF is highly expressed in the cerebellum, mainly in granule
cells. Both acute and chronic stress change BDNF expression in the brain. Although the impact of stress on BDNF
levels showed the different results, BDNF is believed to protect neurons from injuries caused by stress.