Biomaterial Database

Reward summation and the effects of dopamine D1 and D2 agonists and antagonists on fixed-interval responding for brain stimulation. 1994

G E Hunt, and D M Atrens, and D M Jackson

Department of Psychiatry, University of Sydney, New South Wales, Australia.

The effects of dopamine D1 and D2 agonists and antagonists on fixed-interval (FI) self-stimulation were investigated using a reward-summation model, trading off frequency with train duration. The D1 antagonist SCH 23390 (0.005-0.02 mg/kg) decreased FI self-stimulation and the inhibition was reversed by increasing stimulation frequency. Moreover, amphetamine (0.5 mg/kg) reversed the inhibition by a low dose of SCH 23390 (0.005 mg/kg) but not after a higher dose inhibition could not be dissociated from a performance deficit. There was no significant interaction between low doses of spiperone and SCH 23390 when coadministered that could not be predicted from their effects when given individually. Self-stimulation was inhibited by the D1 agonist SKF 38393 (5 mg/kg). When coadministered with amphetamine, SKF 38393 partially blocked amphetamine's facilitation. The D2 agonist bromocriptine (10 mg/kg) produced an extraordinary enhancement of performance that was also evident after a lower dose (5 mg/kg) when it was combined with amphetamine. This enhancement of performance showed little extinction when stimulation was no longer available, suggesting it was a novel form of stereotypy. These results support the concept that D1 dopamine receptors play a critical role in modulating the reinforcing consequences of lateral hypothalamic stimulation. The involvement of D2 receptors on reinforcement processes remains contentious due to their effects on performance and insensitivity of responding to coincide with changes in reinforcement magnitude.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D012055	Reinforcement Schedule	A schedule prescribing when the subject is to be reinforced or rewarded in terms of temporal interval in psychological experiments. The schedule may be continuous or intermittent.	Reinforcement Schedules,Schedule, Reinforcement,Schedules, Reinforcement
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D001971	Bromocriptine	A semisynthetic ergotamine alkaloid that is a dopamine D2 agonist. It suppresses prolactin secretion.	2-Bromoergocryptine,Bromocryptin,2-Bromo-alpha-ergocryptine,2-Bromo-alpha-ergokryptine,2-Bromoergocryptine Mesylate,2-Bromoergocryptine Methanesulfonate,2-Bromoergokryptine,Bromocriptin,Bromocriptine Mesylate,CB-154,Parlodel,2 Bromo alpha ergocryptine,2 Bromo alpha ergokryptine,2 Bromoergocryptine,2 Bromoergocryptine Mesylate,2 Bromoergocryptine Methanesulfonate,2 Bromoergokryptine,CB 154,CB154,Mesylate, 2-Bromoergocryptine,Mesylate, Bromocriptine,Methanesulfonate, 2-Bromoergocryptine
D003216	Conditioning, Operant	Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.	Instrumental Learning,Learning, Instrumental,Operant Conditioning,Conditionings, Operant,Instrumental Learnings,Learnings, Instrumental,Operant Conditionings
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D000661	Amphetamine	A powerful central nervous system stimulant and sympathomimetic. Amphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulation of release of monamines, and inhibiting monoamine oxidase. Amphetamine is also a drug of abuse and a psychotomimetic. The l- and the d,l-forms are included here. The l-form has less central nervous system activity but stronger cardiovascular effects. The d-form is DEXTROAMPHETAMINE.	Desoxynorephedrin,Levoamphetamine,Phenopromin,l-Amphetamine,Amfetamine,Amphetamine Sulfate,Amphetamine Sulfate (2:1),Centramina,Fenamine,Mydrial,Phenamine,Thyramine,levo-Amphetamine,Sulfate, Amphetamine,l Amphetamine,levo Amphetamine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001552	Benzazepines	Compounds with BENZENE fused to AZEPINES.