Changes in the incorporation of [3H]leucine into proteins of rat hippocampus subregions during the acquisition of a brightness discrimination are lateralized.
The incorporation of intraventricularly injected L-[4,5-3H]leucine into proteins of rat hippocampus subregions ("CA 1", "CA 3" and "Ca 4/area dentata") was studied during the acquisition of a footshock-motivated brightness discrimination. In passive controls, protein synthesis rates in CA 3 was significantly increased over those of CA 1 and CA 4/area dentata. Moreover, in left CA 3 L-leucine incorporation rates were significantly elevated when compared to those of the controlateral side. These differences between hippocampus subregions and left and right CA 3 were found to be not dependent on the technique of L-leucine application, but left-right differences did not exist under in vitro conditions. During training, protein synthesis rate in right CA 3 was increased by about + 30% (p less than 0.05) over that of active or passive controls. The trend in CA 1 was not significant. Protein labelling in left hippocampal subregions and, in addition, right CA 4/area dentata exhibited no differences between trained and non-trained animals. Pretreatment of rats with uridine-5'-phosphate improving long-term memory formation resulted in an augmentation of L-leucine incorporation into proteins of CA 1 and CA 3 of trained animals when compared to controls, whilst in other hippocampal subregions no differences in incorporation rates were found between trained and nontrained rats. The present data provided evidence for a hemispheric asymmetry of training-induced changes in protein synthesis in CA 1 and CA 3 of rat hippocampus.
D000818:Animals; D004193:Discrimination Learning; D007839:Functional Laterality; D006624:Hippocampus / Q000378:metabolism*; D007276:Injections, Intraventricular; D007930:Leucine / Q000008:administration & dosage / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D009419:Nerve Tissue Proteins; D007930:Leucine