title: Cognitive processing impairments in a supra-second temporal discrimination task in rats with cerebellar lesion.
abstract: The role of interpositus nuclei (IN) in timing in the sub-second range is well supported in eyeblink conditioning studies. Timing impairments shown in the seconds range in patients with intermediate cerebellar lesion, and known intermediate cerebellar cortex projection to IN raise the question of a possible involvement of IN in timing in the supra-second range as well. To address this question, we tested rats (Sprague-Dawley) given bilateral lesions of IN with Colchicine in a 2- vs. 8-s temporal discrimination task, followed by three daily sessions of a temporal bisection tests with five added intermediate non-reinforced durations. IN lesioned rats showed normal acquisition of the temporal discrimination, but a transient impairment of temporal sensitivity during the bisection tests. In addition, their response latencies suggested a different behavioral strategy from that of control animals. Our results indicate that the IN of the cerebellum may not be critically involved in temporal processing in the 2-8 s range, but may play a role in the cognitive processes that access temporal information in the mediation of choice behavior.
authors.affiliation: Laboratoire de Neurobiologie de l'Apprentissage, de la Mémoire et de la Communication, CNRS UMR 8620, Bat.446, Université Paris Sud, 91405 Orsay, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Callu
authors.forename: Nicole
authors.initials: N
authors.lastname: El Massioui
authors.forename: Gérard
authors.initials: G
authors.lastname: Dutrieux
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Brown
authors.forename: Valérie
authors.initials: V
authors.lastname: Doyere
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001307:Auditory Perception; D002526:Cerebellar Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D002531:Cerebellum / Q000473:pathology / Q000503:physiopathology; D002755:Choice Behavior; D003072:Cognition Disorders / Q000503:physiopathology*; D003078:Colchicine; D004193:Discrimination Learning / Q000502:physiology; D008297:Male; D011597:Psychomotor Performance; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D012054:Reinforcement, Psychology; D013998:Time Perception / Q000502:physiology*
chemical_list: D003078:Colchicine