ALTERATIONS IN DENDRITIC SPINE DENSITY IN THE RAT-BRAIN ASSOCIATED WITH PROTEIN-MALNUTRITION

Rats that consume a high-protein dict are hyperactive, hyperresponsive to noxious stimuli, and demonstrate elevated basal arousal levels. Although the mechanism involved in dietary protein-induced changes in behavior is unclear, it may involve many changes including abnormal dendrite morphology in the brain. Three groups of rats were pair-fed with isocaloric diets containing 8%, 20% and 50% casein for 4 weeks. Their brains were processed for examination of dendritic spine densities in the frontal, parietal, and entorhinal cortices, the striatum. and the septum. Animals on the 50% casein diet showed increased spine densities in all areas investigated (P < 0.05), compared to the animals on normal (20%) casein. In contrast, animals maintained on the 8% casein diet showed increased spine densities (P < 0.05) only in the striatum and entorhinal cortex, and exhibited normal densities in the frontal and parietal cortices, and the medial septum.