Influence of Electrotonic Structure and Synaptic Mapping on the Receptive Field Properties of a Collision-Detecting Neuron

The lobula giant movement detector (LGMD) is a visual interneuron of Orthopteran insects involved in collision avoidance and escape behavior. The LGMD possesses a large dendritic field thought to receive excitatory, retinotopic projections from the entire compound eye. We investigated whether the LGMD's receptive field for local motion stimuli can be explained by its electrotonic structure and the eye's anisotropic sampling of visual space. Five locust ( Schistocerca americana) LGMD neurons were stained and reconstructed. We show that the excitatory dendritic field and eye can be fitted by ellipsoids having similar geometries. A passive compartmental model fit to electrophysiological data was used to demonstrate that the LGMD is not electrotonically compact. We derived a spike rate to membrane potential transform using intracellular recordings under visual stimulation, allowing direct comparison between experimental and simulated receptive field properties. By assuming a retinotopic mapping giving equal weight to each ommatidium and equally spaced synapses, the model reproduced the experimental data along the eye equator, though it failed to reproduce the receptive field along the ventral-dorsal axis. Our results illustrate how interactions between the distribution of synaptic inputs and the electrotonic properties of neurons contribute to shaping their receptive fields.

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Spatiotemporal Receptive Field Properties of a Looming-Sensitive Neuron in Solitarious and Gregarious Phases of the Desert Locust

Journal of Neurophysiology ◽

10.1152/jn.00855.2009 ◽

2010 ◽

Vol 103 (2) ◽

pp. 779-792 ◽

Cited By ~ 24

Author(s):

Stephen M. Rogers ◽

George W. J. Harston ◽

Fleur Kilburn-Toppin ◽

Thomas Matheson ◽

Malcolm Burrows ◽

...

Keyword(s):

Receptive Field ◽

Schistocerca Gregaria ◽

Visual Space ◽

Lifestyle Changes ◽

Movement Detector ◽

Local Motion ◽

Gregarious Locusts ◽

Spatiotemporal Receptive Field ◽

Field Organization ◽

Receptive Field Organization

Desert locusts ( Schistocerca gregaria ) can transform reversibly between the swarming gregarious phase and a solitarious phase, which avoids other locusts. This transformation entails dramatic changes in morphology, physiology, and behavior. We have used the lobula giant movement detector (LGMD) and its postsynaptic target, the descending contralateral movement detector (DCMD), which are visual interneurons that detect looming objects, to analyze how differences in the visual ecology of the two phases are served by altered neuronal function. Solitarious locusts had larger eyes and a greater degree of binocular overlap than those of gregarious locusts. The receptive field to looming stimuli had a large central region of nearly equal response spanning 120° × 60° in both phases. The DCMDs of gregarious locusts responded more strongly than solitarious locusts and had a small caudolateral focus of even further sensitivity. More peripherally, the response was reduced in both phases, particularly ventrally, with gregarious locusts showing greater proportional decrease. Gregarious locusts showed less habituation to repeated looming stimuli along the eye equator than did solitarious locusts. By contrast, in other parts of the receptive field the degree of habituation was similar in both phases. The receptive field organization to looming stimuli contrasts strongly with the receptive field organization of the same neurons to nonlooming local-motion stimuli, which show much more pronounced regional variation. The DCMDs of both gregarious and solitarious locusts are able to detect approaching objects from across a wide expanse of visual space, but phase-specific changes in the spatiotemporal receptive field are linked to lifestyle changes.

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Fine and distributed subcellular retinotopy of excitatory inputs to the dendritic tree of a collision-detecting neuron

Journal of Neurophysiology ◽

10.1152/jn.00044.2016 ◽

2016 ◽

Vol 115 (6) ◽

pp. 3101-3112 ◽

Cited By ~ 10

Author(s):

Ying Zhu ◽

Fabrizio Gabbiani

Keyword(s):

Compound Eye ◽

Visual Stimulation ◽

Dendritic Tree ◽

Visual Space ◽

Dendritic Morphology ◽

Movement Detector ◽

Two Photon ◽

Visual Inputs ◽

Dendritic Computation ◽

Dendritic Branches

Individual neurons in several sensory systems receive synaptic inputs organized according to subcellular topographic maps, yet the fine structure of this topographic organization and its relation to dendritic morphology have not been studied in detail. Subcellular topography is expected to play a role in dendritic integration, particularly when dendrites are extended and active. The lobula giant movement detector (LGMD) neuron in the locust visual system is known to receive topographic excitatory inputs on part of its dendritic tree. The LGMD responds preferentially to objects approaching on a collision course and is thought to implement several interesting dendritic computations. To study the fine retinotopic mapping of visual inputs onto the excitatory dendrites of the LGMD, we designed a custom microscope allowing visual stimulation at the native sampling resolution of the locust compound eye while simultaneously performing two-photon calcium imaging on excitatory dendrites. We show that the LGMD receives a distributed, fine retinotopic projection from the eye facets and that adjacent facets activate overlapping portions of the same dendritic branches. We also demonstrate that adjacent retinal inputs most likely make independent synapses on the excitatory dendrites of the LGMD. Finally, we show that the fine topographic mapping can be studied using dynamic visual stimuli. Our results reveal the detailed structure of the dendritic input originating from individual facets on the eye and their relation to that of adjacent facets. The mapping of visual space onto the LGMD's dendrites is expected to have implications for dendritic computation.

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Receptive-field properties of neurons in different laminae of visual cortex of the cat

Journal of Neurophysiology ◽

10.1152/jn.1978.41.4.948 ◽

1978 ◽

Vol 41 (4) ◽

pp. 948-962 ◽

Cited By ~ 73

Author(s):

A. G. Leventhal ◽

H. V. Hirsch

Keyword(s):

Visual Cortex ◽

Receptive Field ◽

Striate Cortex ◽

Visual Stimulation ◽

Receptive Fields ◽

Spontaneous Discharge ◽

C Cells ◽

Receptive Field Properties ◽

Discharge Rates ◽

Y Cells

1. Receptive-field properties of neurons in the different layers of the visual cortex of normal adult cats were analyzed quantitatively. Neurons were classified into one of two groups: 1) S-cells, which have discrete on- and/or off-regions in their receptive fields and possess inhibitory side bands; 2) C-cells, which do not have discrete on- and off-regions in their receptive fields but display an on-off response to flashing stimuli. Neurons of this type rarely display side-band inhibition. 2. As a group, S-cells display lower relative degrees of binocularity and are more selective for stimulus orientation than C-cells. In addition, within a given lamina the S-cells have smaller receptive fields, lower cutoff velocities, lower peak responses to visual stimulation, and lower spontaneous activity than do the C-cells. 3. S-cells in all layers of the cortex display similar orientation sensitivities, mean spontaneous discharge rates, peak response to visual stimulation, and degrees of binocularity. 4. Many of the receptive-field properties of cortical cells vary with laminar location. Receptive-field sizes and cutoff velocities of S-cells and of C-cells are greater in layers V and VI than in layers II-IV. For S-cells, preferred velocities are also greater in layers V and VI than in layers II-IV. Furthermore, C-cells in layers V and VI display high mean spontaneous discharge rates, weak orientation preferences, high relative degrees of binocularity, and higher peak responses to visual stimulation when compared to C-cells in layers II and III. 5. The receptive-field properties of cells in layers V-VI of the striate cortex suggest that most neurons that have their somata in these laminae receive afferents from LGNd Y-cells. Hence, our results suggest that afferents from LGNd Y-cells may play a major part in the cortical control of subcortical visual functions.

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Coherent alpha oscillations link current and future receptive fields during saccades

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1701672114 ◽

2017 ◽

Vol 114 (29) ◽

pp. E5979-E5985 ◽

Cited By ~ 9

Author(s):

Sujaya Neupane ◽

Daniel Guitton ◽

Christopher C. Pack

Keyword(s):

Receptive Field ◽

Neural Coding ◽

Visual Stimulation ◽

Receptive Fields ◽

Visual Space ◽

Spatial Arrangement ◽

Brain Regions ◽

Alpha Oscillations ◽

Area V4 ◽

Before And After

Oscillations are ubiquitous in the brain, and they can powerfully influence neural coding. In particular, when oscillations at distinct sites are coherent, they provide a means of gating the flow of neural signals between different cortical regions. Coherent oscillations also occur within individual brain regions, although the purpose of this coherence is not well understood. Here, we report that within a single brain region, coherent alpha oscillations link stimulus representations as they change in space and time. Specifically, in primate cortical area V4, alpha coherence links sites that encode the retinal location of a visual stimulus before and after a saccade. These coherence changes exhibit properties similar to those of receptive field remapping, a phenomenon in which individual neurons change their receptive fields according to the metrics of each saccade. In particular, alpha coherence, like remapping, is highly dependent on the saccade vector and the spatial arrangement of current and future receptive fields. Moreover, although visual stimulation plays a modulatory role, it is neither necessary nor sufficient to elicit alpha coherence. Indeed, a similar pattern of coherence is observed even when saccades are made in darkness. Together, these results show that the pattern of alpha coherence across the retinotopic map in V4 matches many of the properties of receptive field remapping. Thus, oscillatory coherence might play a role in constructing the stable representation of visual space that is an essential aspect of conscious perception.

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Visual Deprivation Retards the Maturation of Dendritic Fields and Receptive Fields of Mouse Retinal Ganglion Cells

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2021.640421 ◽

2021 ◽

Vol 15 ◽

Author(s):

Hui Chen ◽

Hong-Ping Xu ◽

Ping Wang ◽

Ning Tian

Keyword(s):

Receptive Field ◽

Retinal Ganglion Cells ◽

Visual Stimulation ◽

Ganglion Cells ◽

Receptive Fields ◽

Developmental Changes ◽

Field Size ◽

Dependent Manner ◽

Retinal Ganglion ◽

Dendritic Field

It was well documented that both the size of the dendritic field and receptive field of retinal ganglion cells (RGCs) are developmentally regulated in the mammalian retina, and visual stimulation is required for the maturation of the dendritic and receptive fields of mouse RGCs. However, it is not clear whether the developmental changes of the RGC receptive field correlate with the dendritic field and whether visual stimulation regulates the maturation of the dendritic field and receptive field of RGCs in a correlated manner. The present work demonstrated that both the dendritic and receptive fields of RGCs continuously develop after eye opening. However, the correlation between the developmental changes in the receptive field size and the dendritic field varies among different RGC types. These results suggest a continuous change of synaptic converging of RGC synaptic inputs in an RGC type-dependent manner. Besides, light deprivation impairs both the development of dendritic and receptive fields.

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