Role of side-slip flight in target pursuit: blue-tailed damselflies (Ischnura elegans) avoid body rotation while approaching a moving perch

2018 ◽  
Vol 204 (6) ◽  
pp. 561-577 ◽  
Author(s):  
Ziv Kassner ◽  
Gal Ribak
Keyword(s):  
Body Rotation ◽  
Ischnura Elegans ◽  
Target Pursuit

Effects of postural changes and vestibular lesions on diaphragm and rectus abdominis activity in awake cats

2001 ◽  
Vol 91 (1) ◽  
pp. 137-144 ◽  
Author(s):  
L. A. Cotter ◽  
H. E. Arendt ◽  
J. G. Jasko ◽  
C. Sprando ◽  
S. P. Cass ◽  
...  
Keyword(s):  
Vestibular System ◽  
Muscle Activity ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Abdominal Muscles ◽  
Body Rotation ◽  
Postural Changes ◽  
Before And After ◽  
Awake Cats

Changes in posture can affect the resting length of the diaphragm, requiring alterations in the activity of both the abdominal muscles and the diaphragm to maintain stable ventilation. To determine the role of the vestibular system in regulating respiratory muscle discharges during postural changes, spontaneous diaphragm and rectus abdominis activity and modulation of the firing of these muscles during nose-up and ear-down tilt were compared before and after removal of labyrinthine inputs in awake cats. In vestibular-intact animals, nose-up and ear-down tilts from the prone position altered rectus abdominis firing, whereas the effects of body rotation on diaphragm activity were not statistically significant. After peripheral vestibular lesions, spontaneous diaphragm and rectus abdominis discharges increased significantly (by ∼170%), and augmentation of rectus abdominis activity during nose-up body rotation was diminished. However, spontaneous muscle activity and responses to tilt began to recover after a few days after the lesions, presumably because of plasticity in the central vestibular system. These data suggest that the vestibular system provides tonic inhibitory influences on rectus abdominis and the diaphragm and in addition contributes to eliciting increases in abdominal muscle activity during some changes in body orientation.

Role of the Cerebellar Flocculus Region in Cancellation of the VOR During Passive Whole Body Rotation

2000 ◽  
Vol 84 (3) ◽  
pp. 1599-1613 ◽  
Author(s):  
Timothy Belton ◽  
Robert A. McCrea
Keyword(s):  
Whole Body ◽  
Body Rotation ◽  
Velocity Signal ◽  
Stationary Target ◽  
Head Velocity ◽  
Cerebellar Flocculus ◽  
Ventral Paraflocculus ◽  
Contralateral Eye ◽  
Eye Velocity

A series of studies were carried out to investigate the role of the cerebellar flocculus and ventral paraflocculus in the ability to voluntarily cancel the vestibuloocular reflex (VOR). Squirrel monkeys were trained to pursue moving visual targets and to fixate a head stationary or earth stationary target during passive whole body rotation (WBR). The firing behavior of 187 horizontal eye movement-related Purkinje (Pk) cells in the flocculus region was recorded during smooth pursuit eye movements and during WBR. Half of the Pk cells encountered were eye velocity Pk cells whose firing rates were related to eye movements during smooth pursuit and WBR. Their sensitivity to eye velocity during WBR was reduced when a visual target was not present, and their response to unpredictable steps in WBR was delayed by 80–100 ms, which suggests that eye movement sensitivity depended on visual feedback. They were insensitive to WBR when the VOR was canceled. The other half of the Purkinje cells encountered were sensitive to eye velocity during pursuit and to head velocity during VOR cancellation. They resembled the gaze velocity Pk cells previously described in rhesus monkeys. The head velocity signal tended to be less than half as large as the eye velocity–related signal and was observable at a short (≈40 ms) latency when the head was unpredictably accelerated during ongoing VOR cancellation. Gaze and eye velocity type Pk cells were found to be intermixed throughout the ventral paraflocculus and flocculus. Most gaze velocity Pk cells (76%) were sensitive to ipsilateral eye and head velocity, but nearly half (48%) of the eye velocity Pk cells were sensitive to contralateral eye velocity. Thus the output of flocculus region is modified in two ways during cancellation of the VOR. Signals related to both ipsilateral and contralateral eye velocity are removed, and in approximately half of the cells a relatively weak head velocity signal is added. Unilateral injections of muscimol into the flocculus region had little effect on the gain of the VOR evoked either in the presence or absence of visual targets. However, ocular pursuit velocity and the ability to suppress the VOR by fixating a head stationary target were reduced by approximately 50%. These observations suggest that the flocculus region is an essential part of the neural substrate for both visual feedback–dependent and nonvisual mechanisms for canceling the VOR during passive head movements.

scholarly journals The role of rotation in the evolution of massive stars losing mass

1979 ◽  
Vol 83 ◽  
pp. 367-370
Author(s):  
S. R. Sreenivasan ◽  
W.J.F. Wilson
Keyword(s):  
Mass Loss ◽  
Solid Body ◽  
Massive Stars ◽  
Body Rotation ◽  
Solid Body Rotation

The role of differential and solid body rotation in the evolution of massive stars undergoing mass loss is discussed. The implications for Of, WR, β Cephei stars and shell stars are brought out.

scholarly journals A striatal interneuron circuit for continuous target pursuit

2018 ◽  
Author(s):  
Namsoo Kim ◽  
Haofang E. Li ◽  
Ryan N. Hughes ◽  
Glenn D. R. Watson ◽  
David Gallegos ◽  
...  
Keyword(s):  
The Self ◽  
Target Distance ◽  
Projection Neurons ◽  
Moving Target ◽  
Movement Velocity ◽  
Velocity Transformation ◽  
Striatal Projection Neurons ◽  
Fast Spiking ◽  
Target Pursuit

AbstractMost adaptive behaviors require precise tracking of targets in space. In pursuit behavior with a moving target, mice use distance to target to guide their own movement continuously. Here we show that in the sensorimotor striatum, parvalbumin-positive fast-spiking interneurons (FSIs) can represent the distance between self and target during pursuit behavior, while striatal projection neurons (SPNs), which receive FSI projections, can represent self-velocity. FSIs are shown to regulate velocity-related SPN activity during pursuit, so that movement velocity is continuously modulated by distance to target. Moreover, bidirectional manipulation of FSI activity can selectively disrupt performance by increasing or decreasing the self-target distance. Our results reveal a key role of the FSI-SPN interneuron circuit in pursuit behavior, and elucidate how this circuit implements distance to velocity transformation required for the critical underlying computation.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management
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