Gastrodin Ameliorates Learning and Memory Impairments Caused by Long-Term Noise Exposure

The developing brain is significantly affected by long-term exposure to noise at an early age, leading to functional disorders such as learning and memory impairments. Gastrodin (GAS), a natural organic compound, is an extraction of phenolic glycoside from the rhizome of Gastrodia elata. Clinically, GAS is extensively utilised for the treatment of neurological disorders. This study aimed to explore the effect and mechanism of GAS on noise exposure-induced learning and memory impairments. Rats aged 21 days were exposed to a 90 dB noise environment for 4 weeks and divided into the noise group, the noise + GAS group, and the control group to establish a noise exposure model. After noise exposure treatment, the improvement effect of GAS on the memory of rats was evaluated by Y-maze and Morris water maze. Enzyme-linked immunosorbent assay was utilised to determine the effect of GAS on neurotransmitter levels in the hippocampal tissue of noise-exposed rats. Western blot was applied for the detection of the protein levels of neurotrophic factors. The GAS treatment significantly improved spatial memory and increased the levels of key neurotransmitters (norepinephrine, dopamine and serotonin) and neurotrophic factors (neurotrophin-3 and brain-derived neurotrophic factor) in the hippocampal tissues of noise-exposed rats. These alterations correlate with enhanced cognitive functions, suggesting a neuroprotective effect of GAS against noise-induced cognitive impairments. This study supports the potential of GAS to treat noise-induced learning and memory impairments by modulating neurotransmitter secretion and enhancing the expression levels of neurotrophic factors. These findings offer potential therapeutic avenues for cognitive impairments induced by noise exposure.