[Effects of zinc deficiency in fodder on brain development, learning and memory in rats]

Zinc deficiency (ZD) model was established in young rats starting from their lactation period. Effects of ZD in fodder on brain development and learning and memory were observed with electron microscopy and neurobiochemical and electroneurophysiological methods, and its mechanism was studied. Results showed that 1. brain weight, hippocampal weight, and serum and hippocampal zinc concentrations were significantly lower in ZD group than those in controls; 2. proportion of induced long-term potentiation (LTP) was zero in ZD group and proportion of active avoidance response decreased profoundly in ZD group, significantly lower than that in normal controls whose LTP proportion was 100%; 3. concentrations of excitatory and inhibitory amino acids, glutamic acid, gamma-aminobutyric acid in cerebral cortex and hippocampus and nitrous oxide in hippocampus were significantly higher in ZD group than those in normal one, and content of somatostatin in hippocampus and DNA in pyramidocytes were significantly lower in ZD group than those in normal one; and 4. number of synaptic vesicles in pyramidocytes of hippocampus decreased obviously in ZD group. It suggests that brain development and function are obviously affected by fodder zinc deficiency in rats.