Brain mesolimbic dopamine system

D Mello, G.D. Comparison of some behavioral effects of and electrical brain stimulation of the mesolimbic dopamine system in rats. Psychopharmacology (Berlin) 75 184-192, 1981. 

Corrigall, W.A., Coen, K.M., Adamson, K.L. Self-administered nicotine activates the mesolimbic dopamine system through the ventral tegmental area. Brain Res. 653 278, 1994. 

Imperato A, Cabib S, Pughsi-Allegra S Repeated stressful experiences differently affect the time-dependent responses of the mesolimbic dopamine system to the stressor. Brain Res 601 333-336, 1993... 

Trulson, Michael E., John C. Joe, Susan Babb, and Joachim D. Raese. 1987. "Chronic Cocaine Administration Depletes Tyrosine Hydroxylase Immuno reactivity in the Mesolimbic Dopamine System in the Rat Brain Quantitative Light Microscopic Studies." Brain Research Bulletin 19 39-45. 

Illicit drugs work on the CNS by means of the mesolimbic dopamine system of the brain, which plays a key role in regulating mechanisms of reward [1]. Several... 

Di Chiara G, Acquas E, Carboni E (1991) In P. Willner and J. Scheel-Kruger (eds) Role of mesolimbic dopamine in the motivational effects of drug brain dialysis and place preference studies. In The mesolimbic dopamine system from motivation to action. John Wiley and Sons Publ., Chichester, UK... 

Rassnick S, Stinus L, Koob GF (1993) The effects of 6-hydroxydopamine lesions of the nucleus accumbens and the mesolimbic dopamine system on arai self-administration of ethanol in the fato. Brain Res 623 16-24. 

The concept of stress sensidzation , whereby early life stressors can induce an enhanced reactivity to later environmental adversities (review ed in Read et al., 2005), may also be relevant to the etiology of schizophrenia. This phenomenon, w hich results in abnormal activation of the HPA axis, is thought to involve alterations in the mesolimbic dopamine system (review ed in Laruelle, 2000) resulting in excessive release of dopamine, a hallmark of psychotic episodes (Laruelle et al., 1996). Taken together, it appears likely that prenatal developmental abnormalities in limbic stmctures that regulate the HPA axis predispose this system to sensitivity to stressors in early childhood and adolescent maturation. This predisposition may then play a key role in the precipitation of psychotic episodes, as well as the deterioration of brain function that accompanies the progression of the disease. 

The mesolimbic dopamine system is thought to be involved either directly or indirectly in addiction to many drugs. The dopaminergic neurons of this system have cell bodies in the ventral tegmental area (VTA) of the brain (Fig. 30-30B) and extend into the nucleus accumbens, a region at the base of the striatum that is thought to provide the "rewarding effects,"... 

In 1954, experiments by Olds and Milner revealed that the brain has specialized centers for reward functions. In these studies electrical stimulation of certain brain sites was found to be highly rewarding in the sense that rats operantly respond for electrical stimulation of these brain sites, often to the exclusion of any other activity. A neurotransmitter system that is particularly sensitive to electrical self-stimulation is the mesolimbic dopamine projection that originates in the ventral tegmental area and projects to structures closely... 

All three major brain dopamine (DA) systems (nigros-triatal, mesocortical, and mesolimbic) have been implicated in aggression in animal studies (Miczek et ah, 1994). Brain DA systems appear to be involved in (1) the rewarding or reinforcing aspects of aggression, possibly via mesolimbic and mesocortical DA systems and (2) the initiation, execution, and termination of aggressive behavior patterns, possibly via the nigrostriatal and mesolimbic DA systems. 

These smoked substances interact with the brain s own cannabinoid receptors to trigger dopamine release from the mesolimbic reward system. There are two known cannabinoid receptors, CB1 (in the brain, which is coupled via G proteins and modulates adenylate cyclase and ion channels) and CB2 (in the immune system). The CB1 receptors may mediate not only marijuana s reinforcing properties, but also those of alcohol. There is also an endogenous cannabinoid system (the brain s own marijuana) capable of activating these cannabinoid receptors functionally. These ert-docannabinoids are synthesized by neurons and inactivated by reuptake systems and enzymes in both neurons and glia. 

Costall B, Marsden CD, Naylor RJ, Pycock CJ (1976) The relationship between striatal and mesolimbic dopamine dysfunction and the nature of circling responses following 6-hydroxydopamine and electrolytic lesions of the ascending dopamine systems of rat brain. Brain Res 773 87-113. 

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