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Titolo:
Effects of nucleus prepositus hypoglossi lesions on visual climbing fiber activity in the rabbit flocculus
Autore:
Arts, MP; De Zeeuw, CI; Lips, J; Rosbak, E; Simpson, JI;
Indirizzi:
NYU, Sch Med, Dept Physiol & Neurosci, New York, NY 10016 USA NYU New York NY USA 10016 Dept Physiol & Neurosci, New York, NY 10016 USA Erasmus Univ, Dept Anat, NL-3000 DR Rotterdam, Netherlands Erasmus Univ Rotterdam Netherlands NL-3000 DR DR Rotterdam, Netherlands
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 5, volume: 84, anno: 2000,
pagine: 2552 - 2563
SICI:
0022-3077(200011)84:5<2552:EONPHL>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
ACCESSORY OPTIC-SYSTEM; OLIVO-CEREBELLAR SYSTEM; COMPLEX SPIKE ACTIVITY; CAT INFERIOR OLIVE; DORSAL CAP; PURKINJE-CELLS; OLIVOCEREBELLAR SYSTEM; SPATIAL-ORGANIZATION; EYE-MOVEMENTS; VESTIBULO-CEREBELLUM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
64
Recensione:
Indirizzi per estratti:
Indirizzo: Simpson, JI NYU, Sch Med, Dept Physiol & Neurosci, 550 1st Ave, New York, NY 10016 USA NYU 550 1st Ave New York NY USA 10016 , New York, NY 10016 USA
Citazione:
M.P. Arts et al., "Effects of nucleus prepositus hypoglossi lesions on visual climbing fiber activity in the rabbit flocculus", J NEUROPHYS, 84(5), 2000, pp. 2552-2563

Abstract

The caudal dorsal cap (dc) of the inferior olive is involved in the control of horizontal compensatory eye movements. It provides those climbing fibers to the vestibulocerebellum that modulate optimally to optokinetic stimulation about the vertical axis. This modulation is mediated at least in partvia an excitatory input to the caudal dc from the pretectal nucleus of theoptic tract and the dorsal terminal nucleus of the accessory optic system. In addition, the caudal dc receives a substantial GABAergic input from thenucleus prepositus hypoglossi (NPH). To investigate the possible contribution of this bilateral inhibitory projection to the visual responsiveness ofcaudal dc neurons, we recorded the climbing fiber activity (i.e., complex spikes) of vertical axis Purkinje cells in the flocculus of anesthetized rabbits before and after ablative lesions of the NPH. When the NPH ipsilateral to the recorded flocculus was lesioned, the spontaneous complex spike firing frequency did not change significantly; but when both NPHs were lesioned, the spontaneous complex spike firing frequency increased significantly. When only the contralateral NPH was lesioned, the spontaneous complex spikefiring frequency decreased significantly. Neither unilateral nor bilaterallesions had a significant influence on the depth of complex spike modulation during constant velocity optokinetic stimulation or on the transient continuation of complex spike modulation that occurred when the constant velocity optokinetic stimulation stopped. The effects of the lesions on the spontaneous complex spike firing frequency could not be explained when only theprojections from the NPH to the inferior olive were considered. Therefore we investigated at the electron microscopic level the nature of the commissural connection between the two NPHs. The terminals of this projection werefound to be predominantly GABAergic and to terminate in part on GABAergic neurons. When this inhibitory commissural connection is taken into consideration, then the effects of NPH lesions on the spontaneous firing frequency of floccular complex spikes are qualitatively explicable in terms of relative weighting of the commissural and caudal dc projections of the NPH. In summary, we conclude that in the anesthetized rabbit the inhibitory projection of the NPH to the caudal dc influences the spontaneous firing frequency of floccular complex spikes but not their modulation by optokinetic stimulation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 08/07/20 alle ore 07:46:23