Diminution and reversal of eye movements induced by local stimulation of rabbit cerebellar flocculus after partial destruction of the inferior olive

1978 ◽  
Vol 33 (1) ◽  
Author(s):  
M. Dufoss� ◽  
M. Ito ◽  
Y. Miyashita
Keyword(s):  
Eye Movements ◽  
Inferior Olive ◽  
Cerebellar Flocculus ◽  
Local Stimulation ◽  
Stimulation Of ◽  
Partial Destruction

Eye movements evoked by microstimulation of dorsal cap of inferior olive in the rabbit

1980 ◽  
Vol 43 (1) ◽  
pp. 165-181 ◽  
Author(s):  
N. H. Barmack ◽  
D. T. Hess
Keyword(s):  
Eye Movements ◽  
Opposite Direction ◽  
Significant Interaction ◽  
Inferior Olive ◽  
Vestibular Stimulation ◽  
Low Velocity ◽  
Cerebellar Flocculus ◽  
Stimulus Train

1. Microstimulation was used in an attempt to activate selectively neurons of the dorsal cap of the inferior olive in unanesthetized rabbits, and the eye movements evoked by this microstimulation were recorded. 2. Trains of microstimulation (20--50 microA, 0.1- to 0.2-ms pulses, 10--60 pulses/s, 2--8 s duration) evoked low-velocity conjugate eye movements directed toward the side of the stimulated olive. These evoked eye movements were interrupted by resetting eye movements in the opposite direction and could be evoked only if the rabbit was in darkness. 3. The velocity of the evoked eye movements increased during a stimulus train and gradually decreased after the stimulation was terminated. 4. The low-velocity eye movements appeared to combine with eye movements evoked by vestibular stimulation without any significant interaction. 5. After transection of the olivocerebellar pathway or destruction of the contralateral cerebellar flocculus, dorsal cap microstimulation no longer evoked ipsilaterally directed eye movements.

scholarly journals Spatially resolved microfluidic stimulation of lymphoid tissue ex vivo

The Analyst ◽  
2017 ◽  
Vol 142 (4) ◽  
pp. 649-659 ◽  
Author(s):  
Ashley E. Ross ◽  
Maura C. Belanger ◽  
Jacob F. Woodroof ◽  
Rebecca R. Pompano
Keyword(s):  
Lymph Node ◽  
Targeted Delivery ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Tissue Slices ◽  
Microfluidic Platform ◽  
Spatially Resolved ◽  
Local Stimulation ◽  
Stimulation Of

We present the first microfluidic platform for local stimulation of lymph node tissue slices and demonstrate targeted delivery of a model therapeutic.

Existence in the nucleus incertus of the cat of horizontal-eye-movement-related neurons projecting to the cerebellar flocculus

1995 ◽  
Vol 74 (3) ◽  
pp. 1367-1372 ◽  
Author(s):  
G. Cheron ◽  
S. Saussez ◽  
N. Gerrits ◽  
E. Godaux
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Retrograde Transport ◽  
Great Sensitivity ◽  
Antidromic Activation ◽  
Vertical Movements ◽  
Cerebellar Flocculus ◽  
Nucleus Incertus ◽  
Alert Cats ◽  
Eye Velocity

1. Properties of nucleus incertus (NIC) neurons projecting to the cerebellar flocculus were studied in alert cats by using chronic unit and eye movement recording and antidromic activation. Projection of these neurons onto the flocculus was verified with retrograde transport of horseradish peroxidase after injections in the flocculus. 2. Bipolar stimulation electrodes were implanted into the "middle" zone of each flocculus because this zone is known to be involved in the control of horizontal eye movements. The dorsomedial aspect of the pontine tegmentum was explored with microelectrodes during stimulation of both flocculi. The majority of neurons antidromically activated from the flocculus were found in the caudal part of the NIC. 3. Of the 69 neurons activated from the flocculus, 44 were classified as burst-tonic (BT) neurons; 34 discharged in relation with horizontal movements of the eye, 10 in relation with vertical movements. Of the 14 remaining neurons, 6 were not related to eye movements and 8 were classified as burst neurons. The BT neurons of the NIC displayed a great sensitivity to both horizontal eye position and horizontal eye velocity. 4. This study demonstrates the presence of a new group of horizontal eye movement related BT neurons situated in the NIC. The fact that they project to the horizontal floccular zone emphasizes the importance of the functional specialization of the different Purkinje cell zones.

Motor intention activity in the macaque's lateral intraparietal area. I. Dissociation of motor plan from sensory memory

1996 ◽  
Vol 76 (3) ◽  
pp. 1439-1456 ◽  
Author(s):  
P. Mazzoni ◽  
R. M. Bracewell ◽  
S. Barash ◽  
R. A. Andersen
Keyword(s):  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Stimulus Location ◽  
Sensory Memory ◽  
Lateral Intraparietal Area ◽  
Preferred Direction ◽  
Motor Plan ◽  
Stimulation Of

1. The lateral intraparietal area (area LIP) of the monkey's posterior parietal cortex (PPC) contains neurons that are active during saccadic eye movements. These neurons' activity includes visual and saccade-related components. These responses are spatially tuned and the location of a neuron's visual receptive field (RF) relative to the fovea generally overlaps its preferred saccade amplitude and direction (i.e., its motor field, MF). When a delay is imposed between the presentation of a visual stimulus and a saccade made to its location (memory saccade task), many LIP neurons maintain elevated activity during the delay (memory activity, M), which appears to encode the metrics of the next intended saccadic eye movements. Recent studies have alternatively suggested that LIP neurons encode the locations of visual stimuli regardless of where the animal intends to look. We examined whether the M activity of LIP neurons specifically encodes movement intention or the locations of recent visual stimuli, or a combination of both. In the accompanying study, we investigated whether the intended-movement activity reflects changes in motor plan. 2. We trained monkeys (Macaca mulatta) to memorize the locations of two visual stimuli and plan a sequence of two saccades, one to each remembered target, as we recorded the activity of single LIP neurons. Two targets were flashed briefly while the monkey maintained fixation; after a delay the fixation point was extinguished, and the monkey made two saccades in sequence to each target's remembered location, in the order in which the targets were presented. This "delayed double saccade" (DDS) paradigm allowed us to dissociate the location of visual stimulation from the direction of the planned saccade and thus distinguish neuronal activity related to the target's location from activity related to the saccade plan. By imposing a delay, we eliminated the confounding effect of any phasic responses coincident with the appearance of the stimulus and with the saccade. 3. We arranged the two visual stimuli so that in one set of conditions at least the first one was in the neuron's visual RF, and thus the first saccade was in the neuron's motor field (MF). M activity should be high in these conditions according to both the sensory memory and motor plan hypotheses. In another set of conditions, the second stimulus appeared in the RF but the first one was presented outside the RF, instructing the monkey to plan the first saccade away from the neuron's MF. If the M activity encodes the motor plan, it should be low in these conditions, reflecting the plan for the first saccade (away from the MF). If it is a sensory trace of the stimulus' location, it should be high, reflecting stimulation of the RF by the second target. 4. We tested 49 LIP neurons (in 3 hemispheres of 2 monkeys) with M activity on the DDS task. Of these, 38 (77%) had M activity related to the next intended saccade. They were active in the delay period, as expected, if the first saccade was in their preferred direction. They were less active or silent if the next saccade was not in their preferred direction, even when the second stimulus appeared in their RF. 5. The M activity of 8 (16%) of the remaining neurons specifically encoded the location of the most recent visual stimulus. Their firing rate during the delay reflected stimulation of the RF independently of the saccade being planned. The remaining 3 neurons had M activity that did not consistently encode either the next saccade or the stimulus' location. 6. We also recorded the activity of a subset of neurons (n = 38) in a condition in which no stimulus appeared in a neuron's RF, but the second saccade was in the neuron's MF. In this case the majority of neurons tested (23/38, 60%) became active in the period between the first and second saccade, even if neither stimulus had appeared in their RF. Moreover, this activity appeared only after the first saccade had started in all but two of

Vestibular-related eye movements in the rat following selective electrical stimulation of the vestibular sensors

2018 ◽  
Vol 204 (9-10) ◽  
pp. 835-847 ◽  
Author(s):  
Martin Hitier ◽  
Go Sato ◽  
Yan-Feng Zhang ◽  
Yiwen Zheng ◽  
Stephane Besnard ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Stimulation Of

scholarly journals Development of Inflammatory Angiogenesis by Local Stimulation of Fas In Vivo

1997 ◽  
Vol 186 (1) ◽  
pp. 147-152 ◽  
Author(s):  
Luigi Biancone ◽  
Antonella De Martino ◽  
Viviana Orlandi ◽  
Pier Giulio Conaldi ◽  
Antonio Toniolo ◽  
...  
Keyword(s):  
Fas Ligand ◽  
Surrounding Tissue ◽  
Apoptotic Cells ◽  
Lymphocyte Apoptosis ◽  
Ligand Interaction ◽  
Monocytes And Macrophages ◽  
Inflammatory Angiogenesis ◽  
Local Stimulation ◽  
Stimulation Of

Fas–Fas ligand interaction is thought to be a crucial mechanism in controlling lymphocyte expansion by inducing lymphocyte apoptosis. However, Fas is also broadly expressed on nonlymphoid cells, where its function in vivo remains to be determined. In this study, we describe the development of inflammatory angiogenesis induced by agonistic anti-Fas mAb Jo2 in a murine model where Matrigel is used as a vehicle for the delivery of mediators. The subcutaneous implants in mice of Matrigel containing mAb Jo2 became rapidly infiltrated by endothelial cells and by scattered monocytes and macrophages. After formation and canalization of new vessels, marked intravascular accumulation and extravasation of neutrophils were observed. Several mast cells were also detected in the inflammatory infiltrate. The phenomenon was dose and time dependent and required the presence of heparin. The dependency on activation of Fas is suggested by the observation that the inflammatory angiogenesis was restricted to the agonistic anti-Fas mAb and it was absent in lpr Fas-mutant mice. Apoptotic cells were not detectable at any time inside the implant or in the surrounding tissue, suggesting that angiogenesis and cell infiltration did not result from recruitment of phagocytes by apoptotic cells but rather by a stimulatory signal through Fas-engagement. These findings suggest a role for Fas–Fas ligand interaction in promoting local angiogenesis and inflammation.

Movements of the Retinae of Jumping Spiders (Salticidae: Dendryphantinae) in Response to Visual Stimuli

1969 ◽  
Vol 51 (2) ◽  
pp. 471-493 ◽  
Author(s):  
M. F. LAND
Keyword(s):  
Eye Movements ◽  
Spontaneous Activity ◽  
Visual Axis ◽  
Retinal Surface ◽  
Jumping Spiders ◽  
Spatial Alignment ◽  
Edge Detectors ◽  
Central Regions ◽  
Stimulation Of ◽  
Central Fixation

1. Movements made by the principal eyes of jumping spiders (Phidippus and Metaphidippus spp.) have been investigated using an ophthalmoscopic technique which permits simultaneous observation and stimulation of the retinal surface. 2. The eye-movements are produced by six muscles. Four are attached to the carapace, and displace each retina latero-medially and dorso-ventrally. The remaining pair are thin bands of muscle which encircle the eye-tube. These twist the eye-tube, rotating the retina about the visual axis (torsion). 3. The nerve supplying these muscles contains only six axons. Each axon terminates in one of the six muscles. 4. Four types of eye-movements are observed. These are spontaneous activity, saccades, tracking and scanning. All movements are usually conjugate. 5. Spontaneous activity consists of a very variable, periodic side-to-side motion of the retinae. It is associated with states of high excitability, and occurs whether or not there is any structure in the field of view. 6. Saccades occur when a small stimulus (e.g. a dark dot) is presented to, or moved upon, the retinae of either the principal eyes or the antero-lateral eyes. In a saccade the retinae move towards the image of the target so that they come to rest with their central regions fixated on the target. 7. If the target moves the retinae track it, maintaining central fixation. 8. Scanning normally follows a saccade. It consists of an oscillatory, side-to-side movement of the retinae across the stimulus, with a period of 1-2 sec., and a simultaneous torsional movement in which the retinae partially rotate about the visual axes, through an angle of approximately 50° and with a period of 5-15 sec. 9. Jumping spiders distinguish other jumping spiders from potential prey by the geometry of their legs. It is suggested that scanning is a pattern-recognition procedure in which the torsional movements are concerned with the spatial alignment of line or edge detectors, and the horizontal component with providing relative motion between these detectors and the stationary stimulus.

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