The frogs belonging to the speciesRana hexadactyla (Lesson) were subjected to localised muscular exercise and training. The muscular exercise induced decreased proteolysis and elevated soluble and structural protein fractions of the brain. The amino acid oxidations were inhibited resulting into elevated amino acid content. The training programme seems to develop improved ammonia detoxificatory mechanism in the brain. The possible correlation between the training programme and structural organisation of the brain was suggested.