title: Role of basal ganglia and ectostriatum in the context-dependent properties of the optocollic reflex (OCR) in the pigeon (Columba livia): a lesion study.
abstract: The possible participation of basal ganglia and associated structures [dorsal striato-pallidum, nucleus spiriformis lateralis (SpL), ectostriatum] in the elaboration of the optocollic reflex (OCR) was investigated by making bilateral chemical lesions (ibotenic acid). Previous data have shown that both the slow and fast phases of the OCR are dependent on the behavioural context. The slow phase velocity (SPV) and the peak velocity of fast phases obtained in non-flying pigeons ('resting condition') were enhanced in pigeons in which a flying posture was experimentally provoked ('flying condition'). Therefore, the effect of lesions was analysed in pigeons standing in the 'resting' or 'flying' condition. In the 'resting' as in the 'flying' condition, all the lesions provoked a decrease in SPV, which augmented with the stimulation velocity. Velocity step stimuli revealed greater OCR deficits than velocity ramp stimuli. Extensive lesions (including the striato-pallidum, ectostriatum and a part of the neostriatum), as well as SpL lesions, provoked a greater SPV decrease over a longer time than lesions restricted to the striato-pallidum or the ectostriatum. The peak velocity of fast phases was only reduced by the 'extensive lesion' in the 'flying condition'. The present data show that the basal ganglia system is involved in the elaboration of optokinetic responses and suggest that, to work in an optimal range, the optokinetic centres need to receive integrated information from basal ganglia in addition to direct visual input.
authors.affiliation: Laboratoire de Neurobiologie des Réseaux Sensorimoteurs, ESA 7060, 45 rue des Saints-Pères, 75270 Paris, Cedex 06, France. Henri.Gioanni@snv.jussieu.fr
authors.forename: H
authors.initials: H
authors.lastname: Gioanni
authors.forename: A
authors.initials: A
authors.lastname: Sansonetti
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D010856:Columbidae / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D005426:Flight, Animal / Q000502:physiology; D019416:Head Movements / Q000502:physiology*; D007051:Ibotenic Acid / Q000633:toxicity; D017072:Neostriatum / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D010775:Photic Stimulation; D012018:Reflex / Q000502:physiology*; D012146:Rest / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology; D013788:Thalamus / Q000033:anatomy & histology / Q000502:physiology
chemical_list: D018690:Excitatory Amino Acid Agonists; D007051:Ibotenic Acid