Effects of nano-curcumin on noise stress-induced hippocampus-dependent memory impairment: behavioral and electrophysiological aspects

Background: Noise pollution is one of the fundamental factors in the etiology of many disorders. Noise stress adversely affects cognitive behaviors and long-term potentiation (LTP), the candidate mechanism of learning and memory. In the present study, we examined the neuroprotective effects of nano-curcumin on behavioral and electrophysiological aspects of hippocampus-dependent memory in noise-exposed animals.

Methods: The stressed animals received either vehicle (ST) or nano-curcumin (NANO + ST) for 2 weeks. The control groups remained either intact (CON) or received nano-curcumin (NANO + CON). The ST and NANO + ST groups were exposed to daily noise for 2 weeks. The spatial memory was assessed in the Morris water maze. The LTP was investigated through field potential recording in the CA3-CA1 pathway of the hippocampus. Serum corticosterone level was measured at the end of the experiments.

Results: The ST group showed a lower cognitive function and suppressed LTP compared to the CON group. The nano-curcumin treatment improved the maze navigation and LTP induction compared to the ST group. While the stress exposure elevated the serum level of corticosterone in the ST animals, nano-curcumin treatment reduced it.

Conclusions: The nano-curcumin treatment restores impaired behavioral and electrophysiological aspects of learning and memory in the noise-exposed animals. The plasma corticosterone levels may be associated with changes in cognitive behavior and synaptic plasticity.