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No alterations in the performance of two interval timing operant tasks after alpha-difluoromethylornithine (DFMO)-induced cerebellar stunting.
- Source :
-
Behavioural brain research [Behav Brain Res] 2001 Nov 29; Vol. 126 (1-2), pp. 135-46. - Publication Year :
- 2001
-
Abstract
- The cerebellum is critically involved in temporal processes in the millisecond range and may be involved in longer time estimations (i.e. in the seconds range). Estimates in the millisecond range are impaired after developmentally induced cerebellar alterations, however, little is known about the effects of similar alterations on longer timing performance. Appropriately timed DFMO treatment reliably causes cerebellar stunting in rats, however, its effects on temporal estimation performance are unknown. Here, male and female Sprague-Dawley rats were treated with subcutaneous injections of 500 mg/kg DFMO on postnatal days 5-12, causing a 10% cerebellar weight reduction at adulthood. As adults, subjects were tested under one of two paradigms - a differential reinforcement of low response rate (DRL) task requiring that subjects withhold a lever press response for 10-14 s or a temporal response differentiation (TRD) task requiring that subjects maintain a lever press response for 10-14 s. Training and steady-state performance of the DRL and TRD tasks were not significantly altered by DFMO treatment. Performance after acute challenges with two dopaminergic agonists (2.00-7.50 mg/kg methylphenidate and 0.10-1.00 mg/kg d-amphetamine) was measured after which all subjects underwent behavioral extinction. Generally, performance after methylphenidate and d-amphetamine was similar in control and DFMO-treated rats and DFMO treatment had no differential effects on performance during extinction. These results support findings from an earlier study [Ferguson SA, Paule MG, Holson RR. Neonatal dexamethasoneon day 7 in rats causes behavioral alterations reflective of hippocampal, but not cerebellar, deficits. Neurotoxicol Teratol, 2001; 23:57-69] indicating that developmental cerebellar stunting has few effects on time estimation within the range of seconds.
- Subjects :
- Animals
Animals, Newborn
Association Learning drug effects
Brain Mapping
Dexamethasone pharmacology
Dextroamphetamine pharmacology
Dose-Response Relationship, Drug
Female
Hippocampus drug effects
Injections, Subcutaneous
Male
Mental Recall drug effects
Methylphenidate pharmacology
Pregnancy
Rats
Rats, Sprague-Dawley
Cerebellum drug effects
Choice Behavior drug effects
Conditioning, Operant drug effects
Eflornithine pharmacology
Maze Learning drug effects
Orientation drug effects
Time Perception drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0166-4328
- Volume :
- 126
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Behavioural brain research
- Publication Type :
- Academic Journal
- Accession number :
- 11704259
- Full Text :
- https://doi.org/10.1016/s0166-4328(01)00259-5