title: Effect of conditioned stimulus parameters on timing of conditioned Purkinje cell responses.
abstract: Pavlovian eyeblink conditioning is a useful experimental model for studying adaptive timing, an important aspect of skilled movements. The conditioned response (CR) is precisely timed to occur just before the onset of the expected unconditioned stimulus (US). The timing can be changed immediately, however, by varying parameters of the conditioned stimulus (CS). It has previously been shown that increasing the intensity of a peripheral CS or the frequency of a CS consisting of a train of stimuli to the mossy fibers shortens the latency of the CR. The adaptive timing of behavioral CRs probably reflects the timing of an underlying learned inhibitory response in cerebellar Purkinje cells. It is not known how the latency of this Purkinje cell CR is controlled. We have recorded form Purkinje cells in conditioned decerebrate ferrets while increasing the intensity of a peripheral CS or the frequency of a mossy fiber CS. We observe changes in the timing of the Purkinje cell CR that match the behavioral effects. The results are consistent with the effect of CS parameters on behavioral CR latency being caused by corresponding changes in Purkinje cell CRs. They suggest that synaptic temporal summation may be one of several mechanisms underlying adaptive timing of movements.
authors.affiliation: Department of Experimental Medical Science, Lund University, BMC F10, 22184 Lund, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Svensson
authors.forename: Dan-Anders
authors.initials: DA
authors.lastname: Jirenhed
authors.forename: Fredrik
authors.initials: F
authors.lastname: Bengtsson
authors.forename: Germund
authors.initials: G
authors.lastname: Hesslow
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D003655:Decerebrate State / Q000503:physiopathology; D004558:Electric Stimulation; D004576:Electromyography; D004594:Electrophysiology; D005289:Ferrets / Q000502:physiology*; D005552:Forelimb / Q000294:innervation / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D011689:Purkinje Cells / Q000502:physiology*