Disorders of Dopaminergic Systems

There are three dopaminergic systems we are going to study. They are different streams of the mesostriatal dopaminergic system, which originates in area 10, the ventral tegmental area, the substantia nigra, especially area 9 the substantia nigra pars compacta, and area 8 that lies just caudal to it.

Parkinson’s Disease

The first system we’re going to study is the dorsal stream of the mesostriatal dopaminergic system, the Nigrostriatal system, whose degeneration has been linked to Parkinson’s Disease (PD). This stream starts off at the ventral tegmental area (A10), the substantia nigra especially the substantia nigra pars compacta (A9) and A8 that lies just caudal to it. It then goes through the medial forebrain bundle, then the internal capsule, and thereon to the corpus striatum. The corpus striatum is made up of the globus pallidus and the striatum. The striatum is the putamen and caudate nucleus.

Psychostimulants

The second system we’re going to study is the ventral stream of the mesostriatal system, the mesolimbic system, which originates in the same place but goes, via the medial forebrain bundle, through to the nucleus accumbens, the olfactory tubercle, and the ventral caudate-putamen. The innervation of the nucleus accumbens has been implicated in the rewarding properties of psychostimulants.

Schizophrenia

The final system is the mesolimbocortical system, which has been implicated in schizophrenia. This system originates in the same place, but then goes through to the hippocampus, the amygdala, the septum, the nucleus of the diagonal band, the anterior olfactory nucleus, and the limbic cortical areas. The nucleus accumbens and olfactory tubercle are often put in this group. Schizophrenia has been linked to underactivity in the prefrontal cortex, overactivity in the striatum and nucleus accumbens, and inability to ignore irrelevant stimuli to a smaller thalamus.


Home ] Up ] Parkinson's Disease ] Schizophrenia ] Cocaine and Amphetamine ]