The effect of chronic treatment with antipsychotic drugs will be examined in rats with respect to alterations in neurochemical parameters in selected brain regions. An attempt will be made to discriminate changes which are related to behavioral alterations induced by the drugs. In particular, dopamine-containing, GABA-containing and Substance-P-containing pathways within the basal ganglia and GABA-containing outputs from the basal ganglia will be manipulated pharmacologically and the resulting neurochemical and behavioral effects will be compared. Neurochemical parameters to be examined include GABA receptor binding, GABA turnover, and enzymes associated with GABA synthesis and degradation. Behavioral parameters under study include stereotyped hyperactivity induced by dopamine stimulants or intranigral application of GABA agonists, and catalepsy induced by antipsychotic drugs. Both acute and chronic drug treatments will be compared in order to distinguish between short-term and long-term influences of the drugs on the neural circuits of interest. In certain cases, a neural pathway and its target region will be characterized neurochemically and anatomically before examining the influence of antipsychotic drug treatment on the pathway. Emphasis will be placed on research, on expanding the existing methodological and technical capabilities of the laboratory, and on developing additional techniques applicable to the proposed area of investigation. Skills to be expanded and developed include quantitative histochemical procedures for neurotransmitter-associated enzymes, neuroanatomical tracing techniques, high pressure liquid chromatography, procedures for monitoring neurotransmitter synthesis and release in brain slices, methods for transplantation of fetal rat brain nuclei or adrenal chromaffin cells into adult rat brain, radiolabelling of GABA-transaminase for purposes of examining its activity and transport in vivo, and radioimmunoassay procedures for analysis of pepetides.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Scientist Development Award - Research (K02)
Project #
5K02MH000497-04
Application #
3069845
Study Section
Research Scientist Development Review Committee (MHK)
Project Start
1984-04-01
Project End
1989-06-30
Budget Start
1987-08-01
Budget End
1988-06-30
Support Year
4
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Georgetown University
Department
Type
School of Medicine & Dentistry
DUNS #
049515844
City
Washington
State
DC
Country
United States
Zip Code
20057
Segovia, J; Tillakaratne, N J; Whelan, K et al. (1990) Parallel increases in striatal glutamic acid decarboxylase activity and mRNA levels in rats with lesions of the nigrostriatal pathway. Brain Res 529:345-8
Wardas, J; Graham, J; Gale, K (1990) Evidence for a role of glycine in area tempestas for triggering convulsive seizures. Eur J Pharmacol 187:59-66
Maggio, R; Liminga, U; Gale, K (1990) Selective stimulation of kainate but not quisqualate or NMDA receptors in substantia nigra evokes limbic motor seizures. Brain Res 528:223-30
Maggio, R; Gale, K (1989) Seizures evoked from area tempestas are subject to control by GABA and glutamate receptors in substantia nigra. Exp Neurol 105:184-8
Dean, P; Gale, K (1989) Anticonvulsant action of GABA receptor blockade in the nigrotectal target region. Brain Res 477:391-5
Segovia, J; Meloni, R; Gale, K (1989) Effect of dopaminergic denervation and transplant-derived reinnervation on a marker of striatal GABAergic function. Brain Res 493:185-9
Massotti, M; Gale, K (1989) Electroencephalographic evidence for a dose-related biphasic effect of morphine on bicuculline-induced seizures in the rat. Epilepsy Res 4:81-9
Garant, D S; Gale, K (1987) Substantia nigra-mediated anticonvulsant actions: role of nigral output pathways. Exp Neurol 97:143-59
Piredda, S; Pavlick, M; Gale, K (1987) Anticonvulsant effects of GABA elevation in the deep prepiriform cortex. Epilepsy Res 1:102-6
Piredda, S; Gale, K (1986) Anticonvulsant action of 2-amino-7-phosphonoheptanoic acid and muscimol in the deep prepiriform cortex. Eur J Pharmacol 120:115-8

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