Effects Of Vitamin A Deficiency On Brain Development, Learning And Memory In Young Rats

Li TY, Chen LN & Qu P

Children’s Hospital, Chongqing University of Medical Science, Chongqing, China

 

Objective: To study the effects of vitamin A deficiency (VAD) on brain development, learning and memory ability in young rats and it’s mechanisms in molecular biology.

Methods: 6 female Wistar rats were randomly divided into VAD and Control group, and were fed with VA 400 IU/kg and 6500 IU/kg diets from the beginning of pregnancy until young rats aged 7 weeks old, respectively. Growth and development, learning and memory ability, VA level in serum and brain, protein content in brain, cell proliferative cycle of cortex and hippocampus, hippocampus cell ultrastructure changes in electron microscopy of rats and the expression of RARα, RARβ, RXRβand D2R mRNA in brain cell were detected.

Results: (1) The weight increase of VAD group rats was slower than those rats in Control group. (2) Learning and remember scores of VAD rats were significant lower than those of Control group. (3) The protein contents of cortex and hippocampus in VAD group were significant lower than those of Control group. (4) The proliferative indices of cortex and hippocampus in VAD group were higher than those of Control group. (5) The synapses between hippocampus pyramidal cells in VAD group were significantly decreased and the small bubbles in synapses were also decreased. The astrocytes in hippocampus in VAD group were significantly increased. Degeneration was observed in many astrocytes. (6) The expression of RARα, RARβ, RXRβand D2R mRNA in VAD group were lower than those of Control group.

Conclusion: (1) VAD can affect brain development and the ability of leaning and memory in young rats. (2) Brain developmental defects in VAD rats included lower brain protein content and hippocampus cell ultrastructure changes. (3) The brain development, learning and memory defects may be due to decreased expression of RARα, RARβ, RXRβ, D2R in brain cell.

 

 
1838