Self-Motion Signals in Vestibular Nuclei Neurons Projecting to the Thalamus in the Alert Squirrel Monkey

• Published in: Journal of neurophysiology 2009-04, Vol.101 (4), p.1730-1741
• Main Authors: Marlinski, Vladimir, McCrea, Robert A
• Format: Article
• Language: English
• Subjects: Acceleration; Action Potentials - physiology; Afferent Pathways - physiology; Animals; Brain Mapping; Electric Stimulation - methods; Functional Laterality; Models, Neurological; Motion Perception - physiology; Movement - physiology; Rotation; Saimiri - anatomy & histology; Saimiri - physiology; Sensory Receptor Cells - classification; Sensory Receptor Cells - physiology; Thalamus - physiology; Vestibular Nuclei - cytology; Wakefulness - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.90904.2008

Department of Neurobiology, University of Chicago, Chicago, Illinois Submitted 12 August 2008; accepted in final form 23 January 2009 Sixty vestibular nuclei neurons antidromically activated by electrical stimulation of the ventroposterior thalamus were recorded in two alert squirrel monkeys. The majority of these neurons were monosynaptically activated by vestibular nerve electrical stimulation. Forty-seven neurons responded to animal rotations around the earth-vertical axis; 16 of them also responded to translations in the horizontal plane. The mean sensitivity to 0.5-Hz rotations of 80°/s velocity was 0.40 ± 0.31 spikes·s –1 ·deg –1 ·s –1 . Rotational responses were in phase with stimulus velocity. Sensitivities to 0.5-Hz translations of 0.1 g acceleration varied from 92.2 to 359 spikes·s –1 · g –1 and response phases varied from 10.1° lead to –98° lag. The firing behavior in 28 neurons was studied during rotation of the whole animal, of the trunk, and voluntary and involuntary rotations of the head. Two classes of vestibulothalamic neurons were distinguished. One class of neurons generated signals related to movement of the head that were similar either when the head and trunk move together or when the head moves on the stationary trunk. A fraction of these neurons fired during involuntary head movements only. A second class of neurons generated signals related to movement of the trunk. They responded when the trunk moved alone or simultaneously with the head, but did not respond to head rotations while the trunk was stationary. Address for reprint requests and other correspondence: V. Marlinski, Department of Neurobiology, Barrow Neurological Institute, 350 West Thomas Road, Phoenix, AZ 85013 (E-mail: vladimir.marlinski{at}chw.edu )