Acupuncture improves cognitive deficits and increases neuron density of the hippocampus in middle-aged SAMP8 mice.

OBJECTIVES To examine whether acupuncture could improve cognitive deficits and reduce the loss of neurons in mice models of ageing. METHODS Male 7.5-month-old senescence-accelerated mouse prone 8 (SAMP8) and age-matched senescence-resistant inbred strains 1 (SAMR1) were divided into four groups (n=15 per group): SAMP8 acupuncture group (Pa), SAMP8 non-acupuncture point control group (Pn), SAMP8 control group (Pc) and SAMR1 normal control group (Rc). The behaviours were examined by the Morris water maze test and the neuron density in the hippocampus was estimated by the optical fractionator technique. RESULTS The Morris water maze test demonstrated that the cognitive deficits of SAMP8 mice were improved by acupuncture treatment. Neuronal loss was found in hippocampal regions CA1 (-24%), CA3 (-18%) and DG (-28%) of Pc compared with Rc. The neuron number in hippocampal CA3 and DG of the Pa group was significantly increased by therapeutic acupuncture compared with the Pc group. CONCLUSIONS Acupuncture improved the cognitive impairment of middle-aged SAMP8 mice which could be attributed to the reduced neuron loss in hippocampal regions CA3 and DG. These results suggest that reducing neuron loss in the hippocampus by acupuncture is a potential therapeutic approach for the treatment of Alzheimer's disease and cognitive impairment diseases.