TY - JOUR
T1 - Modeling operant behavior in the Parkinsonian rat
AU - Avila, Irene
AU - Reilly, Mark P.
AU - Sanabria, Federico
AU - Posadas-Sánchez, Diana
AU - Chavez, Claudia L.
AU - Banerjee, Nikhil
AU - Killeen, Peter
AU - Castañeda, Eddie
N1 - Funding Information:
This work was supported in part by Arizona State University-Office for Vice Provost for Research and the ASU Hispanic Research Center (Eddie Castañeda) and NIDA-KO1 DA00485 (Mark P. Reilly). Irene Avila was supported by a predoctoral fellowship NIH-5 T32 MH18882 from the American Psychological Association Diversity Fellowship Program in Neuroscience; Diana Posadas-Sánchez was supported by NIMH R01MH066860; Claudia L. Chavez was supported in part by a grant from the National Institutes of Health through the Minority Access to Research Careers program NIH-5 T34 GM08491-10; Nikhil Banerjee was supported in part by a grant from the Howard Hughes Medical Institute through the ASU Undergraduate Biology Enrichment Program.
PY - 2009/3/17
Y1 - 2009/3/17
N2 - Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains three parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson's disease. Rats were trained to lever press under a 5-component fixed-ratio (5, 15, 30, 60, and 100) schedule of food reinforcement. Rats were tested for 15 days prior to dopamine lesions and again for 15 days post-lesion. To characterize functional loss relative to lesion size, rats were grouped according to the extent and the degree of lateralization of their dopamine loss. Response rates decreased as a function of dopamine depletion, primarily at intermediate ratios. MPR accounted for 98% of variance in pre- and post-lesion response rates. Consistent with reported disruptions in motor behavior induced by dopaminergic lesions, estimates of δ increased when dopamine was severely depleted. There was no support for different estimates of a based on pre- and post-lesion performance of any lesion group, suggesting that dopamine loss has negligible effects on incentive motivation. The present study demonstrates the usefulness of combining operant techniques with a theoretical model to better understand the effects of a neurochemical manipulation.
AB - Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains three parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson's disease. Rats were trained to lever press under a 5-component fixed-ratio (5, 15, 30, 60, and 100) schedule of food reinforcement. Rats were tested for 15 days prior to dopamine lesions and again for 15 days post-lesion. To characterize functional loss relative to lesion size, rats were grouped according to the extent and the degree of lateralization of their dopamine loss. Response rates decreased as a function of dopamine depletion, primarily at intermediate ratios. MPR accounted for 98% of variance in pre- and post-lesion response rates. Consistent with reported disruptions in motor behavior induced by dopaminergic lesions, estimates of δ increased when dopamine was severely depleted. There was no support for different estimates of a based on pre- and post-lesion performance of any lesion group, suggesting that dopamine loss has negligible effects on incentive motivation. The present study demonstrates the usefulness of combining operant techniques with a theoretical model to better understand the effects of a neurochemical manipulation.
KW - Dopamine
KW - Fixed-ratio schedule
KW - MPR
KW - Memory
KW - Motivation
KW - Motor
KW - Operant behavior
KW - Parkinson's disease
UR - http://www.scopus.com/inward/record.url?scp=59749087719&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=59749087719&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2008.11.033
DO - 10.1016/j.bbr.2008.11.033
M3 - Article
C2 - 19073222
AN - SCOPUS:59749087719
SN - 0166-4328
VL - 198
SP - 298
EP - 305
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 2
ER -