title: Inhibitory control deficits in rats with ventral hippocampal lesions.
abstract: Two experiments are reported in which rats with selective hippocampal lesions were tested on 2 prefrontal-dependent tasks. In Experiment 1, we compared the effects of lesions of the ventral hippocampus (vHC), dorsal hippocampus (dHC), and sham control surgery on the 5-choice reaction time task. Whereas rats with lesions of the dHC were indistinguishable from sham controls, those with vHC lesions showed increased premature responses and reduced accuracy throughout the experiment. The subsequent administration of systemic escitalopram (5 mg/kg), a selective serotonin reuptake inhibitor, reduced the number of premature responses in the vHC animals to control levels. In contrast, systemic injections of GBR 12909, a dopamine reuptake inhibitor, failed to ameliorate the impulsive deficit in the vHC group and, in addition, elevated perseverative responding in the vHC group only. In Experiment 2, we tested a separate group of rats with vHC lesions on a touchscreen visual discrimination and reversal learning task. Rats with vHC lesions acquired the visual discrimination as well as sham controls and showed normal inhibitory control of a previously reinforced response during reversal learning. These data support a role for the vHC in inhibitory control functions, especially in the inhibitory control of impulsive actions.
authors.affiliation: Department of Psychology, McGill University, Montreal, Quebec, Canada H3A 1B1.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Abela
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Dougherty
authors.forename: Erin D
authors.initials: ED
authors.lastname: Fagen
authors.forename: Carolyn J R
authors.initials: CJ
authors.lastname: Hill
authors.forename: Y
authors.initials: Y
authors.lastname: Chudasama
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001288:Attention / Q000187:drug effects / Q000502:physiology; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology*; D015283:Citalopram / Q000494:pharmacology; D004192:Discrimination, Psychological / Q000187:drug effects / Q000502:physiology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005518:Food Preferences / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000293:injuries* / Q000502:physiology; D007175:Impulsive Behavior / Q000139:chemically induced / Q000503:physiopathology*; D007266:Inhibition, Psychological; D008297:Male; D010775:Photic Stimulation; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012193:Reversal Learning / Q000187:drug effects; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D013395:Sucrose / Q000008:administration & dosage; D013549:Sweetening Agents / Q000008:administration & dosage
chemical_list: D015283:Citalopram; D018765:Dopamine Uptake Inhibitors; D010879:Piperazines; D017367:Selective Serotonin Reuptake Inhibitors; D013395:Sucrose; D013549:Sweetening Agents; C043425:vanoxerine