Optic lobe‐compound eye system in cricket: A complete circadian system

1985 ◽  
Vol 16 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Kenji Tomioka ◽  
Yoshihiko Chiba
Development ◽  
1984 ◽  
Vol 83 (1) ◽  
pp. 189-211
Author(s):  
D. J. Emery ◽  
K. A. Bell ◽  
W. Chapco ◽  
J. D. Steeves

A reduced-eye (re) mutant grasshopper of Melanoplus sanguinipes has been characterized by small flat compound eyes lacking facets, no lateral ocelli and only a remnant of the median ocellus. The re grasshoppers walk, jump, fly and feed in a normal manner, but do not respond to visual and auditory stimuli, suggesting they may be blind and deaf. Extracellular recordings from the ventral nerve cord of re mutants verified the lack of neural activity in response to visual and auditory inputs, yet the mutants detected mechanical and tactile stimuli. Electroretinograms implied that a visual deficit may be within the photoreceptors of the compound eye. Histological examination of the compound eyes and ocelli indicated that the cells of the mutant compound eye incompletely differentiate. The optic lamina underlying the retina is missing, as is the outer optic chiasma. The medulla and lobula of the mutant optic lobe are present, however, the neuropil of the medulla lacks the characteristic axonal projection patterns of wild-type grasshoppers. The re grasshopper also lacks all ocellar nerves. Ocellar nerves are normally formed from processes of second order ocellar neurons (SONs), suggesting that if the mutant SONs are present within the protocerebrum, their morphology is drastically altered. Comparison of embryos and juvenile nymphs supports the suggestion that the alterations in the re visual system are the result of abnormal differentiation during development. Even though there is clear evidence of morphological alterations in second and third order optic lobe interneurons, one higher order visual interneuron of the midbrain, the descending contralateral movement detector (DCMD), has the same morphology as the DCMD in a wildtype brain. In this instance, the complete deprivation of the primary sensory input does not appear to alter cellular development.


Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 235-255
Author(s):  
Robert J. Stark ◽  
Michael I. Mote

The compound eyes of Periplaneta americana are connected by optic fibre tracts to an optic lobe composed of three sequential ganglia, the lamina, the medulla and the lobula respectively. The eyes and optic ganglia are organized into repeating sub-units arranged in a regular pattern. During postembryonic development, the number of subunits in the eye (ommatidia) increases from between 50 and 60 to over 2000, with a concomitant increase in the size of the optic lobe ganglia. The patterns of cell growth and proliferation were examined in serial section autoradiagraphs prepared following long and short exposures to [3H]thymidine during each developmental stage. Aspects of structural differentiation were examined in reduced silver-stained sections of nymphs at each developmental stage. Growth of the eye and optic ganglia resulted from the continuous proliferation of new cells throughout postembryonic development. Unlike other body tissues, growth of this system was independent of the moulting cycle. The pattern of growth observed in the optic ganglia directly reflected the growth of the eye. Growth of the compound eye occurs from a special zone of proliferation and differentiation located along all but its posterior margin. The lamina and medulla both grow by cell proliferation from a single neuroblast region located at the apex of the angle subtended by them. Cells which proliferate distally from this region differentiate into lamina neurons, while those that proliferate proximally differentiate into medulla neurons. Axons growing from these two adjacent regions meet at and add new new fibres to the distal end of the medulla neuropil. Specificity of the interneuronal connexions appears to result from a precise temporospatial sequencing of growth with the formation of the optic ganglia dependent on retinal development.


2020 ◽  
Author(s):  
Sara Arganda ◽  
Andrew P. Hoadley ◽  
Evan S. Razdan ◽  
Isabella B. Muratore ◽  
James F. A. Traniello

AbstractOur understanding of how the design of peripheral sensory structures is coupled with neural processing capacity to adaptively support division of labor is limited. Workers of the remarkably polymorphic fungus-growing ant Atta cephalotes are behaviorally specialized by size: the smallest workers (minims) tend fungi in dark subterranean chambers while larger workers perform tasks mainly outside the nest. These strong differences in worksite light conditions are predicted to influence sensory and processing requirements for vision. We found that eye structure and visual neuropils have been be selected to maximize task performance according to light availability. Minim eyes had few ommatidia, large interommatidial angles and eye parameter values, suggesting selection for visual sensitivity over acuity. Large workers had larger eyes with disproportionally more and larger ommatidia, and smaller interommatidial angles and eye parameter values, reflecting peripheral sensory adaptation to ambient rainforest light. Additionally, optic lobe and mushroom body collar volumes were disproportionately small in minims, and within the optic lobe, lamina and lobula relative volumes increased with worker size whereas the medulla decreased. Visual system phenotypes thus correspond to task specializations in dark or light environments and reflect a functional neuroplasticity underpinning division of labor in this socially complex agricultural ant.


Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 241-258
Author(s):  
Mark S. Nowel

There is a topographical mapping of neural elements onto the lamina neuropile of the optic lobe of the cockroach, such that adjacent ommatidia project to adjacent points (optic cartridges) in the lamina neuropile. Postembryonic growth of the compound eye occurs by addition of new ommatidia to its growing margin. Retinula axons grow from the newly formed ommatidia to the lamina. By transplantation experiments in which the position or the orientation of retinal material is altered, it is shown that retinula axons do not make connections in the lamina with respect to their old position and orientation, but rather, in keeping with their new situations, apparently maintaining a retinotopic mapping upon the optic lobe.


1973 ◽  
Vol 58 (3) ◽  
pp. 565-583
Author(s):  
JOHN PATTERSON

1. A muscle attached to the medial edge of the compound eye is described for the blowfly Calliphora vomitoria. 2. Electrophysiological activity in the form of continuous tonically firing potentials can be recorded extracellularly from the muscle. These potentials are generated by the muscle and have the same origin as the ‘clock-spikes’ recorded previously from the optic lobe of Calliphora erythrocephala. 3. The interspike interval of the eye muscle potentials varies inversely with the ambient temperature. 4. Light-adaptation results in a decrease and dark-adaptation an increase in the resting interspike interval of the eye-muscle potentials. 5. Light-adaptation is correlated with increase and dark-adaptation with decrease in the depth of the compound eye as measured at the insertion of the muscle. 6. The pseudopupil produced by illumination of the compound eye from the inside displays spontaneous movements which can be correlated with the anatomical arrangement and spontaneous activity of the eye muscle. 7. The probable function of spontaneous and transient changes in eye-muscle activity is to promote scanning of the visual images produced by the dioptrics of the compound eye.


2011 ◽  
Vol 366 (1565) ◽  
pp. 680-687 ◽  
Author(s):  
Uwe Homberg ◽  
Stanley Heinze ◽  
Keram Pfeiffer ◽  
Michiyo Kinoshita ◽  
Basil el Jundi

Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization–vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions.


2001 ◽  
Vol 204 (19) ◽  
pp. 3303-3310
Author(s):  
Monika Bałys ◽  
Elżbieta Pyza

SUMMARYThe visual system of a fly expresses several circadian rhythms that have been detected in the photoreceptors of the compound eye and in the first neuropile, the lamina, of the underlying optic lobe. In the lamina, axons of two classes of interneuron, L1 and L2, exhibit cyclical size changes, swelling by day and shrinking by night. These rhythmic size changes may be generated by circadian oscillators located inside and/or outside the optic lobe. To localize such oscillators, we have examined changes in the axonal cross-sectional areas of L1 and L2 within the lamina of the housefly (Musca domestica) under conditions of 12 h of light and 12 h of darkness (LD12:12), constant darkness (DD) or continuous light (LL) 24 h after the medulla was severed from the rest of the brain. After the lesion, the axon size changes of L1 and L2 were maintained only in LD conditions, but were weaker than in control flies. In DD and LL conditions, they were eliminated. This indicates that circadian rhythms in the lamina of a fly are generated central to the lamina and medulla neuropiles of the optic lobe. Cyclical changes of light and darkness in LD conditions are still able, however, to induce a weak daily rhythm in the axon sizes of L1 and L2.


2016 ◽  
Author(s):  
Mehmet F. Keleş ◽  
Mark A. Frye

SUMMARYMany animals rely on vision to detect objects such as conspecifics, predators, and prey. Hypercomplex cells of the feline cortex and small target motion detectors of the dragonfly and hoverfly optic lobe demonstrate robust tuning for small objects with weak or no response to elongated edges or movement of the visual panorama [1–4]. However, the relationship between anatomical, molecular, and functional properties of object detection circuitry is not understood. Here, we characterize a previously identified lobula columnar neuron (LC11) in Drosophila [5]. By imaging calcium dynamics with two-photon excitation microscopy we show that LC11 responds to the non-directional motion of a small object darker than the background, with little or no responses to static flicker, elongated bars, or panoramic gratings. LC11 dendrites reside at the boundary between GABA-ergic and cholinergic layers of the lobula, each dendrite spans enough columns to sample 75-degrees of visual space, yet the functional receptive field is only 20-degrees wide, and shows robust responses to an object spanning less than one 5-degree facet of the compound eye. The dendrites of neighboring LC11s encode object motion retinotopically, but the axon terminals fuse into a glomerular structure in the central brain where retinotopy is lost. Blocking inhibitory ionic currents abolishes small object sensitivity and facilitates responses to elongated bars and gratings. Our results reveal high acuity small object motion detection in the Drosophila optic lobe.


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