Rostral Fastigial Nucleus Activity in the Alert Monkey During Three-Dimensional Passive Head Movements

• Published in: Journal of neurophysiology 1997-03, Vol.77 (3), p.1432-1446
• Main Authors: Siebold, C, Glonti, L, Glasauer, S, Buttner, U
• Format: Article
• Language: English
• Subjects: Animals; Eye Movements - physiology; Head Movements - physiology; Macaca mulatta; Neurons - physiology; Orientation - physiology; Otolithic Membrane - innervation; Otolithic Membrane - physiology; Physical Stimulation; Rotation; Semicircular Canals - innervation; Semicircular Canals - physiology; Space life sciences; Vestibular Nuclei - anatomy & histology; Vestibular Nuclei - cytology; Vestibular Nuclei - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.1997.77.3.1432

C. Siebold , L. Glonti , S. Glasauer , and U. Büttner Department of Neurology and Center for Sensorimotor Research, Ludwig Maximilians University, D 81377 Munich, Germany Siebold, C., L. Glonti, S. Glasauer, and U. Büttner. Rostral fastigial nucleus activity in the alert monkey during three-dimensional passive head movements. J. Neurophysiol. 77: 1432-1446, 1997. The fastigial nucleus (FN) receives vestibular information predominantly from Purkinje cells of the vermis. FN in the monkey can be divided in a rostral part, related to spinal mechanisms, and a caudal part with oculomotor functions. To understand the role of FN during movements in space, single-unit activity in alert monkeys was recorded during passive three-dimensional head movements from rostral FN. Seated monkeys were rotated sinusoidally around a horizontal earth-fixed axis (vertical stimulation) at different orientations 15° apart (including roll, pitch, vertical canal plane and intermediate planes). In addition, sinusoidal rotations around an earth-vertical axis (yaw stimulus) included different roll and pitch positions (±10°, ±20°). The latter positions were also used for static stimulation. One hundred fifty-eight neurons in two monkeys were modulated during the sinusoidal vertical search stimulation. The vast majority showed a uniform response pattern: a maximum at a specific head orientation (response vector orientation) and a null response 90° apart. Detailed analysis was obtained from 111 neurons. On the basis of their phase relation during dynamic stimulation and their response to static tilt, these neurons were classified as vertical semicircular canal related ( n  = 79, 71.2%) or otolith related ( n  = 25; 22.5%). Only seven neurons did not follow the usual response pattern and were classified as complex neurons. For the vertical canal-related neurons ( n = 79) all eight major response vector orientations (ipsilateral or contralateral anterior canal, posterior canal, roll, and nose-down and nose-up pitch) were found in FN on one side. Neurons with ipsilateral orientations were more numerous and on average more sensitive than those with contralateral orientations. Twenty-eight percent of the vertical canal-related neurons also responded to horizontal canal stimulation. None of the vertical canal-related neurons responded to static tilt. Otolith-related neurons ( n  = 25) had a phase relation close to head position and were considerably less numerous than canal-related neurons. Excep