PMID: 6108526Jan 1, 1980Paper

L-tyrosine hydroxylase activity in the rat brain after chronic oral administration of manganese chloride

Neurobehavioral Toxicology
E Bonilla

Abstract

In rats chronically treated with a high oral load of MnCl2 a significant increase in the activity of L-tyrosine hydroxylase was observed in neostriatum, midbrain and hippocampus one month after the beginning of the experiment. The augmented enzymatic activity persisted in neostriatum, midbrain and hypothalamus on the third month and remained elevated only in neostriatum on the sixth month. After eight months a significant decrease in the activity of the enzyme was found in neostriatum with no changes in the remaining regions studied. These findings are interesting since human manganese intoxication starts with a psychiatric phase bearing similarities to schizophrenia in which the primary disturbance has been suggested to be an overactivity of dopamine neurons. On the contrary, the permanent neurological phase is associated with reduced striatal dopamine, presumably due to a decrease in L-tyrosine hydroxylase activity.

Related Concepts

Related Feeds

Amygdala and Midbrain Dopamine

The midbrain dopamine system is widely studied for its involvement in emotional and motivational behavior. Some of these neurons receive information from the amygdala and project throughout the cortex. When the circuit and transmission of dopamine is disrupted symptoms may present. Here is the latest research on the amygdala and midbrain dopamine.