Midbrain dopamine system

The motor activation produced by psychomotor stimulants has been long associated with the midbrain dopamine systems. While focused stereotyped behavior produced by high doses of indirect sympathomimetics is blocked by removal of dopamine terminals in the corpus striatum (Creese and Iversen 1975), the locomotor activation produced by low doses of indirect sympathomimetics is blocked by removal of dopamine terminals in the region of the nucleus accumbens (Kelly et al. 1975). This dopaminergic substrate for psychostimulant effects appears selective for the indirect sympathomimetics in that dopamine lesions to the region of the nucleus... 

Moore, R. Y. Organization of midbrain dopamine systems and the pathophysiology of Parkinson s disease. Parkinsonism Relat. Disord. 9(Suppl 2) S65-S71,2003. 

Nisell M, Nomikos GG, Svensson TH. (1995). Nicotine dependence, midbrain dopamine systems and psychiatric disorders. Pharmacol Toxicol. 76(3) 157-62. 

The role of dopamine in the sleep-wake cycle is still, unfortunately, obscure. One hopes Solms will himself take up this important and unresolved issue as a way of testing his intriguing but entirely speculative hypothesis that dreaming can occur if and only if the forebrain dopamine systems are activated. Activation can occur, according to Solms, in any phase of sleep and without the participation of the brain stem caudal to the midbrain sources of dopamine. 

Zaborszky L, Vadasz C (2001) The midbrain dopaminergic system anatomy and genetic variation in dopamine neuron number of inbred mouse strains. Behav Genetics 37 47-59. 

The extrapyramidal motor system controls muscle movement through a system of pathways and nerve tracts that connect the cerebral cortex, basal ganglia, thalamus, cerebellum, reticular formation, and spinal neurons. Patients with PD lose dopamine neurons in the substantia nigra, which is located in the midbrain within the brain stem. The substantia... 

Dopaminergic neuromodulatory system. The neurons that synthesize dopamine (structural formula in box) are found in the midbrain, from which they project to the limbic system (the mesolimbic pathway), the cerebral cortex (the mesocortical pathway), as well as to the extrapyramidal motor system (the nigrostriatal pathway). 

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