Dopamine electrophysiological effects

Greenhoff, J and Johnson, SW (1997) Electrophysiological effects of dopamine receptor stimulation. In The Dopamine Receptors (Eds Neve, KA and Neve, RL), Humana Press, Totowa, NJ, pp. 267-304. 

Dopamine receptor blocking agents. Many of the neuroleptics used in the treatment of schizophrenia frequently produce parkinsonian symptoms as unwanted effects. Neuroleptics block dopamine receptors and their therapeutic effect seems to be related to this action. Although these drugs act on DA systems without distinction, some are more selective. Thioridazine, clozapine and molindone, for example, have electrophysiological effects in the limbic region of the brain but little action in the nigro-striatal area. This selectivity may be related to receptor subtype specificity (see Chs 12 and 54). 

Stockton ME, Rasmussen K. Electrophysiological effects of olanzapine, a novel atypical antipsychotic, on A9 and A10 dopamine neurons. Neuropsychopharmacology 1996 14 97-104. 

Hu, XT and Wang, RY (1988) Comparison of effects of Dj and D2 dopamine receptor agonists on neurons in the rat caudate putamen an electrophysiological study. J. Neurosci. 8 4340-4348. 

Wu, X. and French, E.D., Effects of chronic delta9-tetrahydrocannabinol on rat midbrain dopamine neurons an electrophysiological assessment, Neuropharmacology, 39, 391, 2000. 

Minabe Y, Shirayama Y, Hashimoto K, Routledge C, Hagan JJ, Ashby CR Jr. Effect of the acute and chronic administration of the selective 5-HT6 receptor antagonist SB-271046 on the activity of midbrain dopamine neurons in rats an in vivo electrophysiological study. Synapse 2004 52 20-28. 

Hollerman JR, Grace AA (1990) The effects of dopamine-depleting brain lesions on the electrophysiological activity of rat substantia nigra dopamine neurons. Brain Res 533 203-212. 

Studies in rodent models suggested a DA D2 autoreceptor mechanism of action for 85. In electrophysiological studies in anesthetized rats, compound 85 was able to completely block firing of substantia nigra DA neurons, an effect believed to involve activation of presynaptic DA D2 autoreceptors. Inhibition of brain dopamine synthesis in rats as measured by decreases in GBL induced DOPA levels, as well as decreases in striatal DA levels in in vivo microdialysis studies, were also consistent with a DA autoreceptor mechanism of action. Similar results were measured in in vivo microdialysis studies carried out in a squirrel monkey, suggesting that the compound was also acting as a DA partial agonist. Reductions in the DA levels of the caudate putamen of a monkey were observed after ip administration of 85. 

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