Neuronal basis of a sensory analyser, the acridid movement detector system. III. Control of response amplitude by tonic lateral inhibition

1976 ◽  
Vol 65 (3) ◽  
pp. 617-625
Author(s):  
C. H. Fraser Rowell ◽  
M. O'Shea
Keyword(s):  
Visual Field ◽  
Lateral Inhibition ◽  
Optic Lobe ◽  
Inhibitory Effect ◽  
Test Area ◽  
Detector System ◽  
Movement Detector ◽  
Field Change ◽  
Surrounding Area ◽  
Small Areas

1. The Lobular Giant Movement Detector neurone (LGMD) of Schistocerca responds with spikes when small areas of the visual field change in luminance. Previous work has shown that changes of +/− 1 log 10 unit are enough to produce maximal ON and OFF responses. 2. Using a 5 degree test area, it is shown that the number of spikes generated by such a stimulus depends on the luminance of the surrounding area. When the surround is dark, the response is maximal; when it is brightly lit, the response is minimal. Intermediate intensities produce intermediate values of response. A X 2 change in response is produced by about 3 log 10 units change in surround intensity. 3. A bright annulus, with diameters of 10-5 degrees and 25-8 degrees, inhibits both ON and OFF responses when concentric with the 5 degree test area, but not when it is 30 degrees eccentric to the test area. The inhibitory effect shows no decrease after 4 min. 4. These results are interpreted to indicate a tonic lateral inhibitory network, sited peripherally in the optic lobe prior to the divergence of the separate ON and OFF channels found in the projection from the medulla to the LGMD. It is probably identical with that described for the lamina by previous workers.

scholarly journals The neuronal basis of a sensory analyser, the acridid movement detector system. I. Effects of simple incremental and decremental stimuli in light and dark adapted animals

1976 ◽  
Vol 65 (2) ◽  
pp. 273-288
Author(s):  
C. H. Rowell ◽  
M. O'shea
Keyword(s):  
Dark Adaptation ◽  
Action Potentials ◽  
Light Adaptation ◽  
Test Area ◽  
Detector System ◽  
Retinula Cell ◽  
Movement Detector ◽  
Contralateral Movement ◽  
Adaptation Action

1. The response of the movement detector (MD) system to proportionally constant incremental and decremental stimuli has been studied at various degrees of light and dark adaptation. Action potentials in the descending contralateral movement detector neurone were taken as the indicator of response. 2. Over a range of at least six log10 units of adapting luminance, the MD system behaves as an ON/OFF unit, giving responses to both incremental and decremental changes in the illumination of a 5 degrees target. 3. With increasing amplitudes of stimuli, both the ON and OFF responses saturate rapidly. Saturation is reached sooner at higher levels of light adaptation. At all levels of light adaptation, the OFF response is greater than the ON. The ratio for saturating stimuli is approximately constant at around 3:2. 4. At the brightest adapting luminances used (20 000 cd/m2) the ON response is reduced but not lost. At the lowest (0–004 cd/m2) the OFF response to a 5 degrees disc fails, but can be regained by increasing the test area to 10 degrees. 5. From what is known of the retina of locusts and other insects, it is thought that light and dark adaptation in the MD system can be adequately explained by events at the retinula cell.

The Anatomy of a Locust Visual Interneurone; the Descending Contralateral Movement Detector

1974 ◽  
Vol 60 (1) ◽  
pp. 1-12
Author(s):  
M. O'SHEA ◽  
C. H. F. ROWELL ◽  
J. L. D. WILLIAMS
Keyword(s):  
Visual Field ◽  
Optic Lobe ◽  
Morphological Description ◽  
Movement Detector ◽  
Branching Pattern ◽  
Suboesophageal Ganglion ◽  
Metathoracic Ganglion ◽  
Prothoracic Ganglion ◽  
Contralateral Movement ◽  
The Brain

1. The DCMD neurone is physiologically well-known and runs from the brain to the metathoracic ganglion. It responds to novel movement of small contrasting objects in the visual field and synapses on metathoracic motoneurones which mediate the jump of the locust. Its anatomy, here reported, has been visualized by intracellular cobalt staining. 2. The soma is 50 µm in diameter and lies on the upper posterior face of the protocerebrum, lateral to the midline. A neurite runs to a thickened integrating segment 20 µm. in diameter, which bears numerous dendrites; none of these extends to the optic lobe. An axon leaves the integrating segment, crosses the brain, thickens to about 17µm and descends the contralateral nerve cord. 3. The descending axon terminates in the metathoracic ganglion, where it has three major branches both ipsi- and contralateral. Its branching in the mesothoracic ganglion is similar, but extends only ipsilaterally; in the prothoracic ganglion there is reduced branching, and in the suboesophageal ganglion none at all. 4. The branching pattern in the metathorax is compatible with, and entirely explicable by, the known synaptic connexions with motoneurones. 5. The morphological description of the cell has made possible intracellular recording from axon, integrating segment and soma.

The Cockroach DCMD Neurone: I. Lateral Inhibition and the Effects of Light- and Dark-adaptation

1982 ◽  
Vol 99 (1) ◽  
pp. 61-90 ◽  
Author(s):  
DONALD H. EDWARDS
Keyword(s):  
Lateral Inhibition ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Absolute Intensity ◽  
Recurrent Network ◽  
Light Spot ◽  
Movement Detector ◽  
Threshold Response ◽  
Inhibitory Network ◽  
Local Background

1. The responses of the cockroach descending contralateral movement detector (DCMD) neurone to moving light stimuli were studied under both light- and dark-adapted conditions. 2. With light-adaptation the response of the DCMD to two moving 2° (diam.) spots of white light is less than the response to a single spot when the two spots are separated by less than 10° (Fig. 2). 3. With light-adaptation the response of the DCMD to a single moving light spot is a sigmoidally shaped function of the logarithm of the light intensity (Fig. 3a). With dark-adaptation the response of a DCMD to a single moving light spot is a bell-shaped function of the logarithm of the stimulus intensity (Fig. 3b). The absolute intensity that evokes a threshold response is about one-and-a-half log units less in the dark-adapted eye than in the light-adapted eye. 4. The decrease in the DCMD's response that occurs when two stimuli are closer than 10°, and when a single bright stimulus is made brighter, indicates that lateral inhibition operates among the afferents to the DCMD. 5. It is shown that this inhibition cannot be produced by a recurrent lateral inhibitory network. A model of the afferent path that contains a non-recurrent lateral inhibitory network can account for the response/intensity plots of the DCMD recorded under both light-adapted and dark-adapted conditions. 6. The threshold intensity of the DCMD is increased if a stationary pattern of light is present near the path of the moving spot stimulus. This is shown to be due to a peripheral tonic lateral inhibition that is distinct from the non-recurrent lateral inhibition described earlier. 7. It is suggested that the peripheral lateral inhibition acts to adjust the threshold of afferents to local background light levels, while the proximal non-recurrent network acts to enhance the acuity of the eye to small objects in the visual field, and to filter out whole-field stimuli.

scholarly journals What causes edge fixation in walking flies?

1990 ◽  
Vol 149 (1) ◽  
pp. 281-292 ◽  
Author(s):  
D. Osorio ◽  
M. V. Srinivasan ◽  
R. B. Pinter
Keyword(s):  
Visual Field ◽  
Lateral Inhibition ◽  
Lucilia Cuprina ◽  
Dark Side ◽  
Dark Line ◽  
Dark Region ◽  
Dark Background ◽  
Mach Band ◽  
Eye Region

The orientation of freely walking flies (female Lucilia cuprina) to lines and stripes in a circular arena is described. The following observations were made. 1. The flies walked straight towards a dark line using the frontal eye region, but a pale line on a dark background was only weakly attractive. 2. In bright conditions flies walked in a curved line towards a black-white edge, the path being convex towards the dark side of the border. The curves indicated that the flies were heading for a point about 5–10 degrees to the dark side of the edge. 3. In dim conditions the edge of a dark region was not especially attractive and flies headed towards any point in the dark area. These observations can be accounted for by assuming that the fly walks towards the darkest region in its visual field (scototaxis). In bright conditions the edges of a dark region become more attractive than its centre. This change could be explained if lateral inhibition creates a ‘Mach-band’ effect, making the edges appear darker than the centre. Thus, fixation behaviour in walking Lucilia females seems to be a simple taxis.

A looming-sensitive pathway responds to changes in the trajectory of object motion

2012 ◽  
Vol 108 (4) ◽  
pp. 1052-1068 ◽  
Author(s):  
Glyn A. McMillan ◽  
John R. Gray
Keyword(s):  
Visual Field ◽  
Firing Rate ◽  
Visual Motion ◽  
Compound Eye ◽  
Angular Acceleration ◽  
Leading Edge ◽  
Object Motion ◽  
Near Miss ◽  
Movement Detector ◽  
Contralateral Movement

Two identified locust neurons, the lobula giant movement detector (LGMD) and its postsynaptic partner, the descending contralateral movement detector (DCMD), constitute one motion-sensitive pathway in the visual system that responds preferentially to objects that approach on a direct collision course and are implicated in collision-avoidance behavior. Previously described responses to the approach of paired objects and approaches at different time intervals (Guest BB, Gray JR. J Neurophysiol 95: 1428–1441, 2006) suggest that this pathway may also be affected by more complicated movements in the locust's visual environment. To test this possibility we presented stationary locusts with disks traveling along combinations of colliding (looming), noncolliding (translatory), and near-miss trajectories. Distinctly different responses to different trajectories and trajectory changes demonstrate that DCMD responds to complex aspects of local visual motion. DCMD peak firing rates associated with the time of collision remained relatively invariant after a trajectory change from translation to looming. Translatory motion initiated in the frontal visual field generated a larger peak firing rate relative to object motion initiated in the posterior visual field, and the peak varied with simulated distance from the eye. Transition from translation to looming produced a transient decrease in the firing rate, whereas transition away from looming produced a transient increase. The change in firing rate at the time of transition was strongly correlated with unique expansion parameters described by the instantaneous angular acceleration of the leading edge and subtense angle of the disk. However, response time remained invariant. While these results may reflect low spatial resolution of the compound eye, they also suggest that this motion-sensitive pathway may be capable of monitoring dynamic expansion properties of objects that change the trajectory of motion.

Central 10-degree visual field change following non-penetrating deep sclerectomy in severe and end-stage glaucoma: preliminary results

2018 ◽  
Vol 256 (8) ◽  
pp. 1489-1498 ◽  
Author(s):  
Igor Leleu ◽  
Benjamin Penaud ◽  
Esther Blumen-Ohana ◽  
Thibault Rodallec ◽  
Raphaël Adam ◽  
...  
Keyword(s):  
Visual Field ◽  
Deep Sclerectomy ◽  
Field Change ◽  
Preliminary Results ◽  
End Stage

scholarly journals Examination of the performance of different pointwise linear regression progression criteria to detect glaucomatous visual field change

2011 ◽  
Vol 40 (4) ◽  
pp. e190-e196 ◽  
Author(s):  
Carlos G De Moraes ◽  
Craig A Liebmann ◽  
Remo Susanna Jr ◽  
Robert Ritch ◽  
Jeffrey M Liebmann
Keyword(s):  
Visual Field ◽  
Linear Regression ◽  
Field Change

scholarly journals Diurnal variation in microcirculation of ocular fundus and visual field change in normal-tension glaucoma

Eye ◽  
2004 ◽  
Vol 18 (7) ◽  
pp. 697-702 ◽  
Author(s):  
T Okuno ◽  
T Sugiyama ◽  
S Kojima ◽  
M Nakajima ◽  
T Ikeda
Keyword(s):  
Visual Field ◽  
Diurnal Variation ◽  
Normal Tension Glaucoma ◽  
Field Change ◽  
Ocular Fundus
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