Neuronal activity in the vestibular nuclei of the alert monkey during vestibular and optokinetic stimulation

1977 ◽  
Vol 27 (5) ◽  
Author(s):  
W. Waespe ◽  
V. Henn
Keyword(s):  
Neuronal Activity ◽  
Vestibular Nuclei ◽  
Optokinetic Stimulation ◽  
Alert Monkey

scholarly journals Adaptive Balance in Posterior Cerebellum

2021 ◽  
Vol 12 ◽  
Author(s):  
Neal H. Barmack ◽  
Vito Enrico Pettorossi
Keyword(s):  
Purkinje Cells ◽  
Stellate Cell ◽  
Semicircular Canals ◽  
Mossy Fibers ◽  
Vestibular Nuclei ◽  
Three Dimensions ◽  
Optokinetic Stimulation ◽  
Afferent Pathways ◽  
Vestibular Nuclear Neurons ◽  
Self Motion

Vestibular and optokinetic space is represented in three-dimensions in vermal lobules IX-X (uvula, nodulus) and hemisphere lobule X (flocculus) of the cerebellum. Vermal lobules IX-X encodes gravity and head movement using the utricular otolith and the two vertical semicircular canals. Hemispheric lobule X encodes self-motion using optokinetic feedback about the three axes of the semicircular canals. Vestibular and visual adaptation of this circuitry is needed to maintain balance during perturbations of self-induced motion. Vestibular and optokinetic (self-motion detection) stimulation is encoded by cerebellar climbing and mossy fibers. These two afferent pathways excite the discharge of Purkinje cells directly. Climbing fibers preferentially decrease the discharge of Purkinje cells by exciting stellate cell inhibitory interneurons. We describe instances adaptive balance at a behavioral level in which prolonged vestibular or optokinetic stimulation evokes reflexive eye movements that persist when the stimulation that initially evoked them stops. Adaptation to prolonged optokinetic stimulation also can be detected at cellular and subcellular levels. The transcription and expression of a neuropeptide, corticotropin releasing factor (CRF), is influenced by optokinetically-evoked olivary discharge and may contribute to optokinetic adaptation. The transcription and expression of microRNAs in floccular Purkinje cells evoked by long-term optokinetic stimulation may provide one of the subcellular mechanisms by which the membrane insertion of the GABAA receptors is regulated. The neurosteroids, estradiol (E2) and dihydrotestosterone (DHT), influence adaptation of vestibular nuclear neurons to electrically-induced potentiation and depression. In each section of this review, we discuss how adaptive changes in the vestibular and optokinetic subsystems of lobule X, inferior olivary nuclei and vestibular nuclei may contribute to the control of balance.

Transfer characteristics of neurons in vestibular nuclei of the alert monkey

1978 ◽  
Vol 41 (6) ◽  
pp. 1614-1628 ◽  
Author(s):  
U. W. Buettner ◽  
U. Buttner ◽  
V. Henn
Keyword(s):  
Low Frequency ◽  
Vertical Axis ◽  
Vestibular Nuclei ◽  
Phase Advance ◽  
Frequency Compensation ◽  
Alert Monkey ◽  
Similar Time ◽  
Time Constants ◽  
Vestibular Neurons ◽  
System Time

1. In the alert monkey, 74 neurons in the vestibular nuclei were investigated during sinusoidal rotation about a vertical axis at frequencies between 0.003 and 0.5 Hz. Phase and gain were determined by a fast Fourier analysis program. 2. Phase advance, relative to turntable velocity, was small between 0.05 and 0.5 Hz. At lower frequencies phase advance increased to 45 degrees at 0.007--0.02 Hz, and 90 degrees at 0.003--0.005 Hz. In agreement with the phase characteristics, a gain decrease of -3 dB was determined between 0.007 and 0.02 Hz. Assuming a linear system, time constants of 9.5, 11.9, and 24.5 s were calculated for three different monkeys. 3. Simultaneously recorded nystagmus exhibited similar time constants as the central vestibular neurons for each monkey. 4. Frequency responses of 11 neurons were recorded from the same monkeys while they were under general anesthesia and the time constants were reduced to 4--7 s. This is the range of time constants seen in the peripheral nerve. 5. The longer time constants in the alert state are due to an integration process, which provides a low-frequency compensation, and is thought to be achieved through a feedback loop involving the reticular formation. 6. In the alert and anesthetized state, monkeys were also exposed to velocity trapezoids. Time constants of decay of neuronal activity were in good agreement with the data obtained during sinusoidal stimulation. 7. A transfer function of the primary vestibular afferents is expanded to include the described low-frequency compensation found in central vestibular neurons in the alert animals.

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