Brief intermittent access to sucrose differentially modulates prepulse inhibition and acoustic startle response in obese CCK-1 receptor deficient rats.
Otsuka Long-Evans Tokushima Fatty (OLETF) rats lack the CCK-1 receptor and are hyperphagic and obese. CCK-1 receptors play a role in prepulse inhibition (PPI) by modulating mesolimbic dopamine transmission, a modulator of sensorimotor gating. Therefore, the present study assessed the effects of brief, daily sucrose access on PPI and acoustic startle response (ASR) in OLETF rat and age-matched non-mutant Long-Evans Tokushima Otsuka (LETO) rats. The results revealed that OLETF rats with sucrose access showed an increased ASR [F(1,16) = 6.84; P < 0.01)], relative to sucrose receiving LETO rats. No significant sucrose effect (P = 0.283) on PPI was noted in OLETF rats, whereas sucrose receiving LETO rats had a significantly lower (P < 0.05) PPI percentage than non-sucrose controls. In contrast, sucrose-receiving OLETF rats expressed significantly higher PPI percentage than LETO rats with identical sucrose presentation (P < 0.01). Taken together, these results suggest that sucrose access alters PPI and ASR in general, and the CCK-1 receptors play a modulatory role in facilitating or inhibiting these responses, respectively. A similar effect may be contributory to the hyperphagic behavioral phenotype of obese animal models with altered central dopamine regulation.
De Jonghe
Bart C
BC
Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, 126 South Henderson, University Park, PA 16802, USA. jbd131@psu.edu
Di Martino
Carmine
C
Hajnal
Andras
A
Covasa
Mihai
M
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D030801:Animals, Genetically Modified; D005247:Feeding Behavior / Q000502:physiology; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects*; D009765:Obesity / Q000235:genetics / Q000503:physiopathology*; D051381:Rats; D020334:Rats, Inbred OLETF; D020318:Rats, Long-Evans; D043886:Receptor, Cholecystokinin A / Q000172:deficiency*; D012022:Reflex, Acoustic / Q000187:drug effects* / Q000502:physiology; D013395:Sucrose / Q000494:pharmacology*; D013549:Sweetening Agents / Q000494:pharmacology*
D043886:Receptor, Cholecystokinin A; D013549:Sweetening Agents; D013395:Sucrose