The long term objective of this project is to understand the biochemical mechanisms involved in the selective alteration of dopaminergic function. In the present studies we plan to examine the behavioral & biochemical effects of chronically treating mice with selective D1 and D2 agonists. We will determine these effects in normal mice and in mice in which a dopaminergic system has been made supersensitive to dopaminergic agonists. The system used to study altered dopaminergic function is the well characterized model of mice with unilateral lesions of the corpus striatum induced by injecting 6-hydroxdopamine. These lesions result in a supersensitive turning behavior in response to dopamine agonists. Our preliminary studies show that it is possible to reverse this behavioral supersensitivity in mice by the continuous administration of apomorphine or selective dopaminergic agonists.
The aims of this proposal are: a) to characterize more fully the effects of these agonists, b) to determine the differential involvement of D1 and D2 dopaminergic systems in dopaminergically mediated behaviors in normal and supersensitive mice and to determine the biochemical correlates of both the dopaminergic supersensitivity and the reversal of this effect induced by the dopamine agonists. Accordingly we will examine the correspondence between altered dopaminergic behavior and: a) the density and properties of postsynaptic D1 and D2 receptors; b) biochemical dopaminergic functions that are coupled to the D1 and D2 receptors--namely, dopamine-stimulated adenylate cyclase activity and inhibition of the release of acetylcholine, respectively; and c) certain post- receptor events that may be responsible for altered dopaminergic function--namely, the activity of calmodulin and the phosphorylation of striatal proteins. The results of these studies should increase our basic understanding of dopaminergic function and ultimately suggest different target sites or novel pharmacotherapies for ameliorating neurologic or psychiatric disorders that involve abnormal dopaminergic activity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
4R37MH042148-05
Application #
3486828
Study Section
Special Emphasis Panel (NSS)
Project Start
1987-08-01
Project End
1994-07-31
Budget Start
1991-09-30
Budget End
1992-07-31
Support Year
5
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Allegheny University of Health Sciences
Department
Type
Schools of Medicine
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19129
Weiss, B; Davidkova, G; Zhou, L W (1999) Antisense RNA gene therapy for studying and modulating biological processes. Cell Mol Life Sci 55:334-58
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Zhou, L W; Zhang, S P; Weiss, B (1996) Intrastriatal administration of an oligodeoxynucleotide antisense to the D2 dopamine receptor mRNA inhibits D2 dopamine receptor-mediated behavior and D2 dopamine receptors in normal mice and in mice lesioned with 6-hydroxydopamine. Neurochem Int 29:583-95
Zhang, S P; Zhou, L W; Morabito, M et al. (1996) Uptake and distribution of fluorescein-labeled D2 dopamine receptor antisense oligodeoxynucleotide in mouse brain. J Mol Neurosci 7:13-28
Zhang, S P; Connell, T A; Price, T et al. (1995) Continuous infusion of clozapine increases mu and delta opioid receptors and proenkephalin mRNA in mouse brain. Biol Psychiatry 37:496-503
Qin, Z H; Zhou, L W; Zhang, S P et al. (1995) D2 dopamine receptor antisense oligodeoxynucleotide inhibits the synthesis of a functional pool of D2 dopamine receptors. Mol Pharmacol 48:730-7

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