Effects of stimulation of frontal cortex, superior colliculus, and neck muscle afferents on interstitiospinal neurons in the cat

1981 ◽  
Vol 44 (2) ◽  
Author(s):  
K. Fukushima ◽  
M. Ohno ◽  
S. Murakami ◽  
M. Kato
Keyword(s):  
Superior Colliculus ◽  
Frontal Cortex ◽  
Muscle Afferents ◽  
Neck Muscle ◽  
Neck Muscle Afferents ◽  
Stimulation Of

Projections of extraocular, neck muscle, and retinal afferents to superior colliculus in the cat: their connections to cells of origin of tectospinal tract

1975 ◽  
Vol 38 (1) ◽  
pp. 10-18 ◽  
Author(s):  
V. C. Abrahams ◽  
P. K. Rose
Keyword(s):  
Superior Colliculus ◽  
Extraocular Muscle ◽  
Stimulus Presentation ◽  
Muscle Afferents ◽  
Neck Muscle ◽  
Long Latency ◽  
Cells Of Origin ◽  
Muscle Afferent ◽  
Deep Layers ◽  
Neck Muscle Afferents

Unit recordings were made in the superior colliculus of cats anesthetized with chloralose and with Pentothal. Electrical stimulation of extraocular muscle afferents and neck muscle afferents excited more units in the superior colliculus than did a variety of moving and stationary visual stimuli. Units responding to neck muscle afferent stimulation fell into three populations; one population firing with a short latency and following stimulus presentation up to 1/s, a second population with a long latency and following stimulus presentation at frequencies lower than 15/min, and a third population exhibiting paired firing. The latencies and firing patterns of the third population combined the characteristics of each of the first two patterns. It is suggested that these characteristics of unit discharges stem from the existence of two pathways from neck muscle afferents to the superior colliculus. The projection is predominantly bilateral. Units responding to neck muscle afferent stimulation are distributed throughout the superior colliculus on the basis of their latencies. Long-latency responses predominate in the superficial layers of the superior colliculus and short-latency responses, while more common in the intermediate and deep layers, predominate in the tegmentum. Extraocular muscle afferent projections to the superior colliculus constitute the single richest projection found in these experiments. While the response patterns and latencies are similar to those of the neck muscle afferents, long-latency responses are the most common and dominate in all collicular regions. Few units in the tegmentum could be excited by extraocular muscle afferents. Both extraocular muscle and neck muscle afferents show considerable convergence with one another and with retinal afferents within the superior colliculus. Cells of origin of the tectospinal tract were identified within the superior colliculus and tegmentum by antidromic excitation from the upper cervical cord. These cells were distributed predominantly within the intermediate and deep layers of the superior colliculus, and sparsely in the superficial layers and tegmentum. Almost 50% of the cells of origin of the tectospinal tract receive a convergent input from extraocular muscle and neck muscle afferents and from the retina. About 30% of the cells were inexcitable to the stimuli employed in these experiments. The significance of these projections is discussed with respect to superior collicular function in the cat and i

Neck Muscle Responses to Stimulation of Monkey Superior Colliculus. II. Gaze Shift Initiation and Volitional Head Movements

2002 ◽  
Vol 88 (4) ◽  
pp. 2000-2018 ◽  
Author(s):  
Brian D. Corneil ◽  
Etienne Olivier ◽  
Douglas P. Munoz
Keyword(s):  
Superior Colliculus ◽  
Neck Muscles ◽  
Head Movements ◽  
Emg Activity ◽  
Neck Muscle ◽  
Gaze Shift ◽  
Antagonist Muscles ◽  
Agonist And Antagonist ◽  
Agonist And Antagonist Muscles ◽  
Stimulation Of

We report neck muscle activity and head movements evoked by electrical stimulation of the superior colliculus (SC) in head-unrestrained monkeys. Recording neck electromyography (EMG) circumvents complications arising from the head's inertia and the kinetics of muscle force generation and allows precise assessment of the neuromuscular drive to the head plant. This study served two main purposes. First, we sought to test the predictions made in the companion paper of a parallel drive from the SC onto neck muscles. Low-current, long-duration stimulation evoked both neck EMG responses and head movements either without or prior to gaze shifts, testifying to a SC drive to neck muscles that is independent of gaze-shift initiation. However, gaze-shift initiation was linked to a transient additional EMG response and head acceleration, confirming the presence of a SC drive to neck muscles that is dependent on gaze-shift initiation. We forward a conceptual neural architecture and suggest that this parallel drive provides the oculomotor system with the flexibility to orient the eyes and head independently or together, depending on the behavioral context. Second, we compared the EMG responses evoked by SC stimulation to those that accompanied volitional head movements. We found characteristic features in the underlying pattern of evoked neck EMG that were not observed during volitional head movements in spite of the seemingly natural kinematics of evoked head movements. These features included reciprocal patterning of EMG activity on the agonist and antagonist muscles during stimulation, a poststimulation increase in the activity of antagonist muscles, and synchronously evoked responses on agonist and antagonist muscles regardless of initial horizontal head position. These results demonstrate that the electrically evoked SC drive to the head cannot be considered as a neural replicate of the SC drive during volitional head movements and place important new constraints on the interpretation of electrically evoked head movements.

Neck muscle and trigeminal input to the upper cervical cord and lower medulla of the cat

1979 ◽  
Vol 57 (6) ◽  
pp. 642-651 ◽  
Author(s):  
V. C. Abrahams ◽  
G. Anstee ◽  
F. J. R. Richmond ◽  
P. K. Rose
Keyword(s):  
Muscle Afferents ◽  
Ventral Horn ◽  
Cervical Cord ◽  
High Threshold ◽  
Neck Muscle ◽  
Afferent Projections ◽  
Muscle Afferent ◽  
Upper Cervical ◽  
Deep Layers ◽  
Neck Muscle Afferents

Experiments on chloralose-anaesthetized cats have shown that low-threshold neck muscle afferents project to laminae IV and V in the dorsal horn of the upper cervical cord, to lamina VI including the region which encompasses the central cervical nucleus, as well as to extensive regions of the ventral horn. At posterior medullary levels projections also exist to laminae IV, V, and VI of the spinal nucleus of V (although those to lamina IV are circumscribed), to the deep layers and lateral margin of the cuneate nucleus, and to the inferior olive. These projections are both from low- and high-threshold afferents. Evidence of a functional relationship between the trigeminal and neck muscle afferent system was found both in the upper cervical cord and lower medulla. About 40% of units in both regions receive a convergent input and when convergence could not be demonstrated, prior stimulation of one modality in some instances affected the responsiveness of the unit to the other modality. A motor role was found for some trigeminal afferent projections to the upper cervical cord. Trigeminal afferents consistently activated antidromically identified motoneurons of splenius, biventer cervicis, and complexus.

Neck afferents and muscle sympathetic activity in humans: implications for the vestibulosympathetic reflex

1998 ◽  
Vol 84 (2) ◽  
pp. 450-453 ◽  
Author(s):  
Chester A. Ray ◽  
Keith M. Hume
Keyword(s):  
Heart Rate ◽  
Vestibular System ◽  
Sympathetic Activity ◽  
Head Rotation ◽  
Muscle Afferents ◽  
Neck Muscle ◽  
Neck Flexion ◽  
Vestibulosympathetic Reflex ◽  
Neck Afferents ◽  
Neck Muscle Afferents

Ray, Chester A., and Keith M. Hume. Neck afferents and muscle sympathetic activity in humans: implications for the vestibulosympathetic reflex. J. Appl. Physiol. 84(2): 450–453, 1998.—We have shown previously that head-down neck flexion (HDNF) in humans elicits increases in muscle sympathetic nerve activity (MSNA). The purpose of this study was to determine the effect of neck muscle afferents on MSNA. We studied this question by measuring MSNA before and after head rotation that would activate neck muscle afferents but not the vestibular system (i.e., no stimulation of the otolith organs or semicircular canals). After a 3-min baseline period with the head in the normal erect position, subjects rotated their head to the side (∼90°) and maintained this position for 3 min. Head rotation was performed by the subjects in both the prone ( n = 5) and sitting ( n = 6) positions. Head rotation did not elicit changes in MSNA. Average MSNA, expressed as burst frequency and total activity, was 13 ± 1 and 13 ± 1 bursts/min and 146 ± 34 and 132 ± 27 units/min during baseline and head rotation, respectively. There were no significant changes in calf blood flow (2.6 ± 0.3 to 2.5 ± 0.3 ml ⋅ 100 ml−1 ⋅ min−1; n = 8) and calf vascular resistance (39 ± 4 to 41 ± 4 units; n = 8). Heart rate (64 ± 3 to 66 ± 3 beats/min; P = 0.058) and mean arterial pressure (90 ± 3 to 93 ± 3; P < 0.05) increased slightly during head rotation. Additional neck flexion studies were performed with subjects lying on their side ( n = 5). MSNA, heart rate, and mean arterial pressure were unchanged during this maneuver, which also does not engage the vestibular system. HDNF was tested in 9 of the 13 subjects. MSNA was significantly increased by 79 ± 12% ( P < 0.001) during HDNF. These findings indicate that neck afferents activated by horizontal neck rotation or flexion in the absence of significant force development do not elicit changes in MSNA. These findings support the concept that HDNF increases MSNA by the activation of the vestibular system.

scholarly journals Neck muscle afferents influence oromotor and cardiorespiratory brainstem neural circuits

2014 ◽  
Vol 220 (3) ◽  
pp. 1421-1436 ◽  
Author(s):  
I. J. Edwards ◽  
V. K. Lall ◽  
J. F. Paton ◽  
Y. Yanagawa ◽  
G. Szabo ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Muscle Afferents ◽  
Neck Muscle ◽  
Neck Muscle Afferents

scholarly journals Neck Muscle Responses to Stimulation of Monkey Superior Colliculus. I. Topography and Manipulation of Stimulation Parameters

2002 ◽  
Vol 88 (4) ◽  
pp. 1980-1999 ◽  
Author(s):  
Brian D. Corneil ◽  
Etienne Olivier ◽  
Douglas P. Munoz
Keyword(s):  
Superior Colliculus ◽  
Head Movements ◽  
Emg Activity ◽  
Eye Position ◽  
Neck Muscle ◽  
Evoked Responses ◽  
Inferior Rectus ◽  
Gaze Shifts ◽  
Stimulation Current ◽  
Stimulation Of

The role of the primate superior colliculus (SC) in orienting head movements was studied by recording electromyographic (EMG) activity from multiple neck muscles following electrical stimulation of the SC. Combining SC stimulation with neck EMG recordings provides an objective and sensitive measure of the SC drive onto neck muscle motoneurons, particularly in relation to evoked gaze shifts. In this paper, we address how neck EMG responses to SC stimulation in head-restrained monkeys depend on the rostrocaudal, mediolateral, and dorsoventral location of the stimulating electrode within the SC and vary with manipulations of the eye position prior to stimulation onset and changes in stimulation current and duration. Stimulation predominantly evoked EMG responses on the muscles obliquus capitis inferior, rectus capitis posterior major, and splenius capitis. These responses became larger in magnitude and shorter in onset latency for progressively more caudal stimulation locations, consistent with turning the head. However, evoked responses persisted even for more rostral stimulation locations usually not associated with head movements. Manipulating initial eye position revealed that the magnitude of evoked responses became stronger as the eyes attained positions contralateral to the side of stimulation, consistent with a summation between a generic command evoked by SC stimulation and the influence of eye position on tonic neck EMG. Manipulating stimulation current and duration revealed that the relationship between gaze shifts and evoked EMG responses is not obligatory: short-duration (<20 ms) or low-current stimulation evoked neck EMG responses in the absence of gaze shifts. However, long-duration stimulation (>150 ms) occasionally revealed a transient neck EMG response aligned on the onset of sequential gaze shifts. We conclude that the SC drive to neck muscle motoneurons is far more widespread than traditionally supposed and is relayed through intervening elements which may or may not be activated in association with gaze shifts.

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