Background: Environmental signals have a crucial role in development of brain’s structure and function during critical period of brain development. Gt was valuated the devebpmental effeck in developmental effect of visual deprivation on synaptic plasticity of Dentate Gyrus neurons was evaluated.

Materials and Methods: This experimental study was carried on 2 groups (n=48) rats kept in standard 12-hour light/dark condition (Light Reared-LR) or in complete darkness (Dark Reared-DR) since birth throughout the study. Each group, in turn, was divided into 3 groups of 2, 6 and 10 weeks old subgroup (n=8 for each). Stimulating the perforant path, field potentials were recorded in the Dentate Gyrus area for 30 minutes. Then, the tetanic stimulation was applied to the Schaffer collaterals and the field potentials were pooled for 120 minutes post-tetanus in all animals.

Results: The basic responses of the LR animals decreased and the amplitude of the DR rats increased, across aging. After the LTP induction, amplitude of responses increased in all groups but the amount and stability of them were lower dark reared in animals than the LR ones.

Conclusion: Change in environmental visual signals impairs basic response and LTP induction in neurons of Dentate Gyrus area of hippocampus.