PSY396H1 Chapter Notes - Chapter 5: Tyrosine Hydroxylase, Dopaminergic Cell Groups, Nigrostriatal Pathway
Document Summary
Catecholamines: a group of neurotransmitters and hormones characterized by two chemical similarities: a core structure of catechol and a nitrogen-containing amine. They belong to a group of monoamines or biogenic amines. The adrenal medulla secretes epi and ne into the bloodstream, where they act as hormones. It determines the overall rate of product formation. In the formation of a catecholamines (da or ne), th is the rate limiting enzyme. Activity of th is regulated by a variety of factors. How much da or ne is present within the nerve terminal high catecholamine levels tend to inhibit th (negative feedback mechanism) Rate of cell firing, neuronal activity has a stimulatory effect on th. Dopa (used to treat parkinson"s disease: -methyl-para-tyrosine (ampt)- blocks th, and prevents the overall catecholamine synthesis (generally causes a depletion of them) Vmat1 found in the adrenal medulla.