Brain receptor

Lthanol (or alcohol) is a two-carbon molecule that, in contrast to many other drugs of abuse, such as opioids, cocaine, and nicotine, does not bind to specific brain receptors. Nonetheless, alcohol affects a variety of neurotransmitter systems, including virtually all of the major systems that have been associated with psychiatric symptoms (Kranzier 1995). Alcohol affects these neurotransmitter systems indirectly by modifying the composition and functioning of... 

Biochemical results (A", in nM) obtained in binding assays of radioactively labeled brain receptors [57] from the same 17 neuroleptics shown in Table 37.9. 

Zukin, S.R., and Zukin, R.S. Identification and characterization of 3H phencyclidine binding to specific brain receptor sites. In Domino, E.F., ed. PCP (phencvli di ne) Hi stori cal and... 

Marks, M., Stitzel, J., Collins, A. Time course study of the effects of chronic nicotine infusion on drug response and brain receptors. J. Pharmacol. Exp. Ther. 235 619, 1985. 

Itzhak, Y. Repeated methamphetamine-treatment alters brain receptors. Eur. J. Pharmacol. 230 243, 1993. 

Zeneroli ML, Baraldi M, Ventura E, Vezzelli C, Tofanetti O, Germini M, Casciarri I Alterations of GABA-A and dopamine D2 brain receptors in dogs with portal-systemic encephalopathy. Life Sci 1991 48 37-50. 

Adams IB, Compton DR, Martin BR. (1998). Assessment of anandamide interaction with the cannabinoid brain receptor SR 141716A antagonism studies in mice and autoradiographic analysis of receptor binding in rat brain. J Pharmacoi Exp Ther. 284(3) 1209-17. 

After 40 years trying to understand drag actions, brain receptors and molecular pharmacology, I realize clearly just how right he was. 

Marks Ml, Stitzel lA, et al (1985) Time course study of the effects of chronic nicotine infusion on drug response and brain receptors. 1 Pharmacol Exp Ther 235(3) 619-628 Marshall DL, Redfem PH, et al (1997) Presynaptic nicotinic modulation of dopamine release in the three ascending pathways studied by in vivo microdialysis comparison of naive and chronic nicotine-treated rats. 1 Neurochem 68(4) 1511-1519 Martinez D, Gil R, et al (2005) Alcohol dependence is associated with blunted dopamine transmission in the ventral striatum. Biol Psychiatry 58(10) 779-786 McClernon El, Kozink RV, Rose IE (2007) Individual differences in nicotine dependence, withdrawal symptoms, and sex predict transient fMRl-BOLD responses to smoking cues. Neuropsychopharmacology 33(9) 2148-2147... 

Part of the reason may be the relatively crude nature of the tools we have had until recently to study brain function. However, this is clearly beginning to change. Genetic research and functional brain imaging, which actually takes pictures of the brain in action, may ultimately give us a glimpse of brain receptor and enzyme activity that was unthinkable just a few years ago. 

Olanzapine (Zyprexa). The olanzapine molecule is structurally very similar to clozapine and therefore exerts very similar effects on brain receptors. The dose range of olanzapine for treating schizophrenia is from 5 to 30mg/day. Like clozapine, olanzapine appears to treat both positive and negative symptoms. It is also approved for the treatment of the manic phase of bipolar disorder. It has also been shown to augment the antidepressant effects of fluoxetine in refractory patients. 

Interference Therapy. This is conceptually the opposite of the replacement and reward therapies. Whereas replacement medications substitute for the abused drug by stimulating the same brain receptors, interference therapies block these receptors. When the substance abuser uses his/her drug of choice, its effects are blocked by the interference medication. As a result, the drug does not produce the same intensity of pleasurable effects. By reducing the pleasurable effects of drug use, the incentive for repeated use should decrease as well. 

The pharmacotherapy drugs that are the subject of this report fall into one of three general classes (l) brain receptor blockers (2) molecule binders or (3) metabolism modifiers. 

Anandamide inhibited the specific binding of [ H]-HU-243 to synaptosomal membranes in a manner typical of competitive ligands, with an inhibition constant (K ) of 39.0 + 5.0 nM. In this system, the of tsP-THC, a psychoactive compound of cannabis, was 46.0 + 3-0 nM. These were exciting results — the psychoactive compound from a higher plant and a chemically completely different compound in the brain were found to bind to the same brain receptor at about the same level of activity. Soon after the identification of anandamide, this compound was tested for its pharmacological activity. Anandamide administered i.p. in mice, caused... 

Fluphenazine (Prolixin, Permitil) [Antipsychotic/ Phenothiazine] Uses Schizophrenia Action Phenothiazine antipsychotic blocks postsynaptic mesolimbic dopamin gic brain receptors Dose 0.5-10 mg/d in % doses PO q6-8h, av age maint 5 mg/d or 1.25 mg IM, then... 

Oxytocin receptors are widely distributed in the brain (Insel et al., 1997). Brain receptors are biochemically identical to receptors found in uterine myometrium and mammary myoepithelium. There is a remarkable diversity across species in the neuroanatomical distribution and regulation of OT receptors. These receptors are heavily controlled by gonadal steroids, and the pattern of steroid regulation of OT receptor expression varies across species as well. This diversity of receptors may be the mechanism through which OT function, and thus the social behaviors influenced by that function vary across species. 

Cusack, B., Nelson, A., and Richelson, E. (1994) Binding of antidepressants to human brain receptors focus on newer generation compounds. Psychopharmacology (Berl) 114 559-565. 

Ametamey, S.M. Westera, G. Gucker, P. SchdnbSchler, R. Honer, M. Spang, J.E. Schubiger, P.A. (2000) Functional brain receptor imaging with positron emission tomography. Chimia, 54, 622-6. 

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