Canal-otolith interaction in the fastigial nucleus of the alert monkey

2001 ◽  
Vol 136 (2) ◽  
pp. 169-178 ◽  
Author(s):  
C. Siebold ◽  
E. Anagnostou ◽  
S. Glasauer ◽  
L. Glonti ◽  
J.F. Kleine ◽  
...  
Keyword(s):  
Fastigial Nucleus ◽  
Alert Monkey

Vestibular Signals in the Fastigial Nucleus of the Alert Monkey

1996 ◽  
Vol 781 (1 Lipids and Sy) ◽  
pp. 304-313 ◽  
Author(s):  
U. BÜTTNER ◽  
CH. SIEBOLD ◽  
L. GLONTI
Keyword(s):  
Fastigial Nucleus ◽  
Alert Monkey

Trunk Position Influences Vestibular Responses of Fastigial Nucleus Neurons in the Alert Monkey

2004 ◽  
Vol 91 (5) ◽  
pp. 2090-2100 ◽  
Author(s):  
J. F. Kleine ◽  
Y. Guan ◽  
E. Kipiani ◽  
L. Glonti ◽  
M. Hoshi ◽  
...  
Keyword(s):  
Stimulus Frequency ◽  
Vestibular Stimulation ◽  
The Body ◽  
Fastigial Nucleus ◽  
Alert Monkey ◽  
Vestibular Information ◽  
Vector Orientation ◽  
The Right ◽  
Head Positions

Vestibulospinal reflexes play an important role for body stabilization during locomotion and for postural control. For an appropriate distribution of vestibular signals to spinal motoneurons, the orientation of the body relative to the head needs to be taken into account. For different trunk positions, identical vestibular stimuli must activate different sets of muscles to ensure body stabilization. Because the cerebellar vermis and the underlying fastigial nucleus (FN) might be involved in this task, vestibular neurons in the rostral FN of alert rhesus monkeys were recorded during sinusoidal vestibular stimulation (0.1–1.0 Hz) in the roll and pitch planes at different trunk-re-head positions (center and ±45°). From the sensitivity and phase values measured in these planes, the response properties in the intermediate planes and the stimulus orientation eliciting the optimal response [response vector orientation (RVO)] were calculated. In most neurons, the RVOs rotated systematically with respect to the head, when trunk-re-head position was altered, so that they tended to maintain their orientation with respect to the trunk. Sensitivity and phase at the RVO were not affected. This pattern was the same for neurons in the right and left FN and independent of stimulus frequency. The average sensitivity of this partially compensatory RVO shift in response to trunk-re-head displacements, evaluated by linear regression analyses, was 0.59°/° ( n = 73 neurons). These data show that FN neurons may encode vestibular information in a coordinate system that is closer to a trunk-centered than to a head-centered reference frame. They indicate an important role of this nucleus in motor programs related to posture and gait control.

Fastigial nucleus activity in the alert monkey during slow eye and head movements

1991 ◽  
Vol 65 (6) ◽  
pp. 1360-1371 ◽  
Author(s):  
U. Buttner ◽  
A. F. Fuchs ◽  
G. Markert-Schwab ◽  
P. Buckmaster
Keyword(s):  
Smooth Pursuit ◽  
Head Movements ◽  
Fastigial Nucleus ◽  
Whole Body ◽  
Oculomotor Control ◽  
Alert Monkey ◽  
Full Field ◽  
Head Velocity ◽  
Small Spot ◽  
Head Rotations

1. Single units were recorded extracellularly from the fastigial nucleus of three macaque monkeys. Two untrained animals were subjected to whole-body yaw rotations in the light and dark and to full-field horizontal optokinetic stimuli provided by a drum with vertical stripes. The third also was subjected to sinusoidal yaw rotations but, in addition, was trained to follow a small spot, which moved in various ways relative to the animal, to reveal possible smooth pursuit and vestibular sensitivities. 2. On the basis of their responses to vestibular and optokinetic stimuli and their responses during smooth pursuit, fastigial neurons could be divided functionally into a rostral and a caudal group. 3. Most rostral neurons exhibited an increased firing for contralateral head rotations and ipsilateral optokinetic stimuli. A few had the opposite combination of directional preferences. The average firing rates increased monotonically both with contralateral head velocity and ipsilateral drum velocity and decreased monotonically for the oppositely directed movements. There was no change in firing rate for either spontaneous saccades or smooth pursuit of a small moving spot. 4. In contrast, neurons in the caudal fastigial nuclei not only have a robust vestibular sensitivity, but respond during smooth pursuit as well. Most discharge during contralateral head velocity and contralateral smooth pursuit so that they exhibit very little modulation during the vestibuloocular reflex (VOR) or when the rotating animal is fixating a target stationary in the world (SIW). The remaining neurons discharge during contralateral head rotations but ipsilateral eye rotations; these units exhibit their greatest modulation during the SIW condition. 5. Because they respond during quite different behavioral situations, it seems likely that rostral fastigial neurons are involved with descending control of the somatic musculature, whereas the caudal neurons are involved in oculomotor control. The sparse anatomic and lesion data that is available is consistent with this idea.

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

1997 ◽  
Vol 77 (3) ◽  
pp. 1432-1446 ◽  
Author(s):  
C. Siebold ◽  
L. Glonti ◽  
S. Glasauer ◽  
U. Büttner
Keyword(s):  
Phase Relation ◽  
Response Pattern ◽  
Three Dimensional ◽  
Head Movements ◽  
Fastigial Nucleus ◽  
Head Orientation ◽  
Alert Monkey ◽  
Horizontal Canal ◽  
Response Vector ◽  
Dynamic Stimulation

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. Except for pitch, all other response vector orientations were found. Seventy percent of these neurons responding during dynamic stimulation also responded during static tilt. The sensitivity during dynamic stimulation was always higher than during static stimulation. Sixty-one percent of the otolith-related neurons responded also to horizontal canal stimulation. These results show that in FN, robust vestibular signals are abundant. Canal-related responses are much more common than otolith-related responses. Although for many canal neurons the responses can be related to single canal planes, convergence between vertical canals but also with horizontal canals is common.

Role of the caudal fastigial nucleus in saccade generation. II. Effects of muscimol inactivation

1993 ◽  
Vol 70 (5) ◽  
pp. 1741-1758 ◽  
Author(s):  
F. R. Robinson ◽  
A. Straube ◽  
A. F. Fuchs
Keyword(s):  
Brain Stem ◽  
Rhesus Macaques ◽  
Fastigial Nucleus ◽  
Gamma Aminobutyric Acid ◽  
End Points ◽  
Acceleration And Deceleration ◽  
Corrective Saccades ◽  
Corrective Saccade ◽  
The Right ◽  
The Brain

1. We studied the effect of temporarily inhibiting neurons in the caudal fastigial nucleus in two rhesus macaques trained to make saccades to jumping targets. We placed injections of the gamma-aminobutyric acid (GABA) agonist muscimol unilaterally or bilaterally at sites in the caudal fastigial nucleus where we had recorded saccade-related neurons a few minutes earlier. 2. Unilateral injections (n = 9) made horizontal saccades to the injected side hypermetric and those to the other side hypometric (mean gain of 1.37 and 0.61, respectively, for 10 degrees target steps, and 1.26 and 0.81 for 20 degrees target steps; normal saccade gain was 0.96). Saccades to vertical targets showed a small but significant hypermetria and curved strongly toward the side of the injection. The trajectories and end points of all targeted saccades were more variable than normal. 3. After unilateral injections, centripetal saccades were slightly larger than centrifugal saccades (mean gains for ipsilateral saccades were 1.42 and 1.31, respectively, for 10 degrees target steps, and 1.37 and 1.15 for 20 degrees target steps). 4. Unilateral injections increased the average acceleration of ipsilateral saccades and decreased the acceleration of contralateral saccades. Injections decreased both the acceleration and deceleration of vertical saccades. 5. After dysmetric saccades, monkeys acquired the target with an abnormally high number of hypometric corrective saccades. Injection increased the average number of corrective saccades from 0.6 to 2.1 after 10 degrees horizontal target steps and from 0.8 to 2.1 after 20 degrees steps. The size of each successive corrective saccade in a series decreased, and the latency from the previous corrective saccade increased. 6. Bilateral injections (n = 2) of muscimol, in which we injected first into the left caudal fastigial nucleus and then, within 30 min, into the right, made all saccades hypermetric (mean gain for 10 degrees right, left, up, and down saccades was 1.18, 1.49, 1.43, and 1.10, respectively). Paradoxically, bilateral injection decreased both saccade acceleration and deceleration. Saccade trajectories and end points were more variable than normal. 7. To account for the effects of our injections, we propose that the activity of caudal fastigial neurons on one side normally helps to decelerate ipsilateral saccades and helps to accelerate contralateral saccades by influencing the feedback loop of the saccade burst generator in the brain stem. Without caudal fastigial activity the brain stem burst generator produces hypermetric, variable saccades. We therefore also propose that the influence of caudal fastigial neurons on the burst generator makes saccades more consistent and accurate.(ABSTRACT TRUNCATED AT 400 WORDS)

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