Mechanical stimulation of a specific acupuncture point reduced depression-like behaviour through a brain growth-factor pathway without restoring estrogen levels.
Researchers used female rats with surgically removed ovaries to model estrogen deficiency, alongside sham-operated rats and untreated estrogen-deficient controls. One treatment group received mechanical stimulation at the Sameumgyo acupuncture point, while another received stimulation at a non-acupuncture location. Behaviour was assessed using tests of movement, anxiety-like exploration, and behavioural despair. The investigators also measured hippocampal brain-derived neurotrophic factor, neuropeptide Y, and estradiol, and blocked the brain-derived neurotrophic factor receptor in some animals to test the proposed mechanism.
Stimulation at the Sameumgyo point improved movement and exploratory behaviour and reduced immobility associated with depression-like behaviour. It increased hippocampal brain-derived neurotrophic factor and neuropeptide Y without restoring estradiol, indicating that its effects were independent of estrogen recovery. Blocking the brain-derived neurotrophic factor receptor prevented the rise in neuropeptide Y, supporting a pathway in which brain-derived neurotrophic factor drives neuropeptide Y signalling to produce antidepressant-like effects.
