On the fine structure of the peripheral retina and lamina ganglionaris of the fly, Musca domestica

Boschek, C. B.

doi:10.1007/bf00331193

Cited by 349 publications

(177 citation statements)

References 42 publications

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“…Light that has propagated through the rhabdomeres is radiated in wave patterns that seem to coalesce near the back nodal plane; the distance between the individual beams increases when focusing proximally (see [ 14] ), in agreement with the anatomical observations that the distance between photoreceptor rhabdomeres increases from the distal tips toward proximally (e.g. [ 15,16] ). Furthermore, the diameter of the beams appears to be minimal at or near the plane of the rhabdomere tips, and the beam widths increase when focusing up or down.…”

Section: Axial Direction Of Photoreceptorssupporting

confidence: 73%

Light-dependent pigment migration in blowfly photoreceptors studied by in vivo CLSM

Stavenga

Leertouwer

Smits

1996

Journal of Photochemistry and Photobiology B: Biology

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The light-dependent migration of pigment granules in the soma of fly photoreceptors has been studied in vivo with a fast confocal laser scanning microscope. Images as well as photometric measurements were obtained in the reflection and fluorescence modes. Measurements at the single cell level were performed by using water immersion. The illumination of dark adapted photoreceptors causes a rapid increase in reflectance due to the migration of light scattering pigment granules toward the rhabdomeres. In the steady-state, the reflection signal strongly fluctuates, indicating that the pigment granules undergo a very rapid fluctuating movements. A major part of the reflection signal is due to light back-scattered by the pigment granules and channeled through the light guiding rhabdomeres. The optical axes of the rhabdomeres can thus be directly traced and appear to be directed toward the optical centre of the corresponding facet lens. Simultaneous with the reflection increase, the fluorescence of the photoreceptors decreases, because the pigment granules accumulating near the rhabdomeres act as a lightcontrolling pupil. Broad-band, white light filtered by the predominantly blue absorbing pupil causes an increased fraction of the visual pigment in the rhodopsin state.

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Section: Axial Direction Of Photoreceptorssupporting

confidence: 73%

Light-dependent pigment migration in blowfly photoreceptors studied by in vivo CLSM

Stavenga

Leertouwer

Smits

1996

Journal of Photochemistry and Photobiology B: Biology

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“…Although the waveguide modes then are different from those in a circular cylinder, the absorption of light by the visual pigment is presumably similar. The assumption that the rhabdomere tapers from distal to proximal in a parabolic fashion is based on the anatomy of Musca (Boschek, 1971). Anatomical data from other flies suggest that tapering is a universal characteristic of R1-R6 photoreceptors.…”

Section: Discussionmentioning

confidence: 99%

“…The pupil pigment granules are distributed in the photoreceptor soma (Boschek, 1971), but experimental data strongly argue in favour of a distal pupil (Roebroek and Stavenga, 1990). What counts for a photoreceptor is not the number of absorbed photons converting rhodopsin molecules but the change in membrane potential created and the signal transmitted by the photoreceptor synapse.…”

Section: Discussionmentioning

confidence: 99%

“…The visual pigment in the rhabdomere absorbs light from the individual modes proportionally to the absorbance coefficient of the rhabdomere medium and the fraction of the mode that exists within the rhabdomere boundary. This fraction increases with V but decreases with increasing p. Fly rhabdomeres taper and their distal tip diameter is somewhat variable (Boschek, 1971). Therefore, four distal rhabdomere diameters were explored in the calculations: Dr=1.4, 1.6, 1.8 and 2.0·µm.…”

Section: Integrated Optics Of the Fly Facet Lens-rhabdomere Systemmentioning

confidence: 99%

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Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil

Stavenga

2004

Journal of Experimental Biology

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SUMMARY The effect of the UV-absorbing sensitizing pigment of fly photoreceptors on absolute, spectral and angular sensitivity was investigated with a wave-optics model for the facet lens-rhabdomere system. When sky light was used as a UV-rich light source, one sensitizing pigment molecule per rhodopsin increased the photoreceptor absorption by 14-18% with respect to pure rhodopsin, whilst two sensitizing pigment molecules per rhodopsin increased the absorption by 20-27%. Upon light adaptation, when the pupil mechanism is activated,photoreceptor absorption decreases; in the housefly, Musca, by up to 6-fold. The fully light-adapted pupil diminishes the photoreceptor's acceptance angle by a factor of ∼0.6 due to selective absorption of higher order waveguide modes. Spatial acuity of dark-adapted photoreceptors is more or less constant throughout the visual wavelength range, including the UV,because the waveguide optics of the rhabdomere compromise acuity least at wavelengths most limited by diffraction of the facet lens. Diffraction is not the general limiting factor causative for UV sensitivity of insect eyes. Visual acuity is governed by diffraction only with a fully light-adapted pupil, which absorbs higher waveguide modes. Closure of the blue-absorbing pupil causes a UV-peaking spectral sensitivity of fly photoreceptors. The sensitizing pigment does not play an appreciable role in modifying spatial acuity, neither in the dark- nor the light-adapted state, due to the dominant contribution of green light in natural light sources.

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“…The neuroanatomy of the fly visual system has been mapped in considerable detail at both the light and ultrastructual levels (Boschek, 1971;Meinertzhagen and O'Neil, 1991;Sinakevitch and Strausfeld, 2004) and an extensive, and sophisticated battery of behavioral assays has been developed to monitor the fly's response to visual stimuli (Borst and Haag, 2002;Heisenberg and Wolf, 1984). Application of picrotoxin suggests that GABAergic signaling is required for some aspects of motion detection in Drosophila (Bülthoff and Bülthoff, 1987).…”

Section: Introductionmentioning

confidence: 99%

Mutation of theDrosophilavesicular GABA transporter disrupts visual figure detection

Fei

Chow

Chen

et al. 2010

Journal of Experimental Biology

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SUMMARYThe role of gamma amino butyric acid (GABA) release and inhibitory neurotransmission in regulating most behaviors remains unclear. The vesicular GABA transporter (VGAT) is required for the storage of GABA in synaptic vesicles and provides a potentially useful probe for inhibitory circuits. However, specific pharmacologic agents for VGAT are not available, and VGAT knockout mice are embryonically lethal, thus precluding behavioral studies. We have identified the Drosophila ortholog of the vesicular GABA transporter gene (which we refer to as dVGAT), immunocytologically mapped dVGAT protein expression in the larva and adult and characterized a dVGAT minos mutant allele. dVGAT is embryonically lethal and we do not detect residual dVGAT expression, suggesting that it is either a strong hypomorph or a null. To investigate the function of VGAT and GABA signaling in adult visual flight behavior, we have selectively rescued the dVGAT mutant during development. We show that reduced GABA release does not compromise the active optomotor control of wide-field pattern motion. Conversely, reduced dVGAT expression disrupts normal object tracking and figure-ground discrimination. These results demonstrate that visual behaviors are segregated by the level of GABA signaling in flies, and more generally establish dVGAT as a model to study the contribution of GABA release to other complex behaviors.

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On the fine structure of the peripheral retina and lamina ganglionaris of the fly, Musca domestica

Cited by 349 publications

References 42 publications

Light-dependent pigment migration in blowfly photoreceptors studied by in vivo CLSM

Light-dependent pigment migration in blowfly photoreceptors studied by in vivo CLSM

Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil

Mutation of theDrosophilavesicular GABA transporter disrupts visual figure detection

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