Dopaminergic systems, activity

Martel P, Fantino M (1996a) Mesolimbic dopaminergic system activity as a function of food reward a microdialysis study. Pharmacol Biochem Behav 53 221-226. 

Desole MS, Miele M, Esposito G, et al. 1994. Dopaminergic system activity and cellular defense mechanisms in the striatum and striatal synaptosomes of the rat subchronically exposed to manganese. Arch Toxicol 68 566-570. 

QUESTION How can you dissociate the locomotor effects from the reinforcing effects It has been agreed that lesions of the mesolimbic system affect locomotor activity and shown by Eberson with respect to the dopaminergic system. How do you know you don t have a rat that is motorically compromised and can t press the lever to get the cocaine How can you dissociate that from the reinforcement efficacy ... 

Furthermore, the presence of CB1 in the structures and pathways associated with the pathophysiology of Tourette s syndrome, and especially the functional link between CB1 and Di, D2, also argues that the endocannabinoid system may have some involvement in this disorder as well (Consroe, 1998). In addition, it has been suggested that activation of CB1 receptors, also owing to their link with the dopaminergic system, may reduce dyskinesia produced by L-DOPA in patients with Parkinson s disease (Brotsie, 1998). 

Pataki et al. showed that apomorphine and bromocriptine enhanced the elevation of body temperature induced by pituitary adenylate cyclase-activating polypeptide in rats and observed that hyperthermia was antagonized by haloperidol, suggesting the involvement of the dopaminergic system (100). 

Stefanski, R., Ladenheim, B., Lee, S.H., Cadet, J.L., Goldberg, S.R. Neuroadaptations in the dopaminergic system after active self-administration but not after passive administration of methamphetamine. Eur. J. Pharmacol. 371 123, 1999. 

In conclusion, measurements of monoamine turnover following treatments with various classes of hallucinogens reveal that most of these drugs decrease the activity of 5-HT synapses and increase that of dopaminergic systems in... 

Morphine generally has sedative effects, reducing overall activity. But local injections into dopaminergic systems can increase locomotor activity, and daily administration can also sensitize one to the locomotor effect (Kalivas and Duffy 1987). High does of opioids create muscle rigidity and catalepsy. 

Overall, the central dopaminergic systems mediating reward appear to be more active in females than males, notwithstanding the fact that there may be exceptions under some conditions. 

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