Brain-specific proteins in the occipital cortex of rats housed in enriched and impoverished environments

The occipital cortex was dissected from the brain of rats housed in either enriched or impoverished environment for four weeks. In environmentally enriched rats the weight of occipital cortex was found to be increased 5.7%, compared to environmentally impoverished rats, and the amount of protein was increased 6.0%. The amount of six nervous system-specific proteins was measured by crossed immunoelectrophoresis. Synaptin increased 4.7%, D3 increased 8.3%, and D1 increased 9.6%, whereas D2 was not significantly increased. Compared to D2, D3 and D1 were still increased significantly, although all were present in synaptosomal membrane fractions. The protein S-100 was increased 3.4% and the neuronal protein 14-3-2 was increased 12.2% for the cathodal component whereas the anodal component was not increased. The results were interpreted as representing delayed development of environment-dependent neurons in the environmentally impoverished rats.