The methylphenidate-induced stereotypy in the awake rat: local cerebral metabolism

The local cerebral metabolic rate for glucose (1=CMRg) was computed in rats with methylphenidate-induced stereotypy using the quantitative 14C-2-deoxyglucose (2-DG) technique. Four rats received methylphenidate 15 mg per kilogram IP. Compared to five control animals, treated rats showed statistically significant (p less than or equal to 0.05) increases in 1-CMRg in globus pallidus, ventral lateral nucleus of the thalamus, subthalamic nucleus, red nucleus, substantia nigra, entopeduncular nucleus, inferior olivary nucleus, and the lateral cerebellar cortex. Significantly, 1-CMRg decreased in area 4 of the motor cortex. The auditory system showed no change in 1-CMRg, demonstrating the specific action of methylphenidate in the rat brain. This technique allows evaluation of the functional anatomy of the entire central nervous system and may be helpful in understanding the mechanisms of methylphenidate-induced stereotypy.