l42 the eye of the fly.ppt - cornell university...warrant, e. and dacke, m. vision and visual...
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11/9/2011
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L42. THE EYE OF THE FLY
C. D. Hopkins
Neuroethology BIONB 4240
Nov 9, 2011
In superposition eyes, light from many focusing lenses converge on a small number of photoreceptors.
No pigment shielding between ommatidiaNight flying insects
In apposition eyes the light from a single photoreceptor is focused on a single rhabdomEric Warrant and Marie Dacke (2011) Ann.
Rev. Entomol.
Cajal’s Anatomical study of the Insect Eye
Cajal wrote, “ the complexity of the insect retina is stupendous, indeed disconcerting, and with no precedent in other animals”
lamina
medulla
lobula
Cajal’s figure reprinted in Llinas (2003) Nature reviews neuroscience
The eye of the fly is divided into ommatidia
Simmons and Young, 2010
Transduction takes place in the rhabdom
locust eye blow fly
rhabdomeres remainseparate
Rhabdom fuses into single light collecting rod
Simmons and Young, 2010
Like vertebrates, insect eyes often have a fovea capable of acute vision
Here, for a praying mantis, the fovea is a small are, forward looking, where the mantis fixates on a prey.
The facet diameter is larger in the fovea. The inter-ommotidial angle is reduced.(more overlap).
Simmons and Young, 2010
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The fovea varies according to the visual behavior of the insect
For four species, contour plots of numbers of ommatidia per unit solid angle.
b) Caliphora (blowfly)
c) Apis male (honeybee)
d) Annax junius (dragonfly)
e) Gerris (waterstrider)
Land, M. (1997) Visual accuity in insects. Annu. Rev. Entomol. 1997. 42:147–77
The speed of the eye varies with the flight patterns of two flies
Tipula: crane fly, is nocturnal, slow flying.
Fleshflies are diurnal, fast moving
0.5 s
Simmons and Young, 2010
the photoreceptor responds with depolarizing potential (overshoot, then relax to plateau)
axon responds
The lamina and a lamina monopolar cell
Simmons and Young, 2010
axon responds with depolarizing potentail.
The LMC neuron is inhibited by the photoreceptor. and is more “phasic”.
DC response is eliminated, edges enhanced. (hi-pass).
S. Laughlin
The lamina neurons enhance the transient (flicker) responses by removing background light levels
From Laughlin, S. (in Shepherd and Grilner: handbook of brain microcircuits, 2010)
The fly lamina enhances the high frequency component of the amplitude modulated light
From Laughlin, S. (in Shepherd and Grilner: handbook of brain microcircuits, 2010)
Werner BernhardReichardt Hassenstein
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Early Experiments
Y-Maze
Glossary
• Luminance
• Contrast
• Temporal frequency=velocity/wavelength(variation that a single ( greceptor sees)
The Reichardt (Correlation) Motion Detector
Photoreceptors
Low-pass filters create delay 1F
1 2
2F
Multiplier
Subtractor
t)-(T(T)FA-t)-(T(T)FA R(t) 2112=
1A2A
Lobula Plate Tangential Cells (LPTC) in the lobula plate of the blow fly, Calliphora, respond to motion in the horizontal plane (HS neurons) (a) or vertical plane (VS neurons) anywhere in the visual field of the eye.
HS VSdownward
ccw
Franceschini et al, 1989 (from Simons and Young, 2010)
H1 neurons allow left right comparisons (distinguish rotation from forward visual flow)
Delay line coincidence detector produces motion response in H1 neurons (elementary motion detector)
Nicholas FranceschiniCNRS, Marseille France
sequential activation of just two photoreceptors within a single ommatidium evoke responses from H1 only in the preferred direction. (From Franceschini et al, 1989)
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Motion sensing neurons in Lobula Plate
Borst & Euler Neuron 71, September 22, 2011
Reichardt Motion Detector Model
Possible connectivity
Egelhaaf and Borst (1993)
ReferencesHassenstein, B. & Reichardt, W. Z. Naturforsch.11b, 513–524 (1956).
Reichardt, W. in Sensory Communication (ed. Rosenblith, W. A.) 303–317 (MIT Press, Cambridge, Massachusetts, 1961).
Borst, A. & Egelhaaf, M. Trends Neurosci. 12, 297–306 (1989).
van Santen, J. P. H. & Sperling, G. J. Opt. Soc. Am. A 2, 300–320 (1985).
Adelson, E. H. & Bergen, J. R. J. Opt. Soc. Am. A 2, 284–299 (1985).
Barlow, H. B. & Levick, W. R. J. Physiol. (Lond.)178, 477–504 (1965).
Koch C Poggio T & Torre V Proc Natl Acad Sci USA 80, 2799–2802 (1983).Koch, C., Poggio, T. & Torre, V. Proc. Natl. Acad. Sci.USA 80, 2799 2802 (1983).
Borst, A. (2000) Models of motion detection. Nature neuroscience supplement 3:1168.
Borst, A. and Euler, T. (2011) Seeing things in motion: models, circuits, and mechanisms. Neuron 71, 974‐94.
Egelhaaf, M. and Borst, A. (1993). Motion computation and visual orientation in flies. Comp Biochem Physiol Comp Physiol 104, 659‐73.
Franceschini, N. Riehle, A. and Le Nestour, A. (19889) Directionally selective motion detection by insect neurons. In Facets of Vision (ed. D. G. Stavenga and R. C. Hardie) pp 360‐390. Berlin. Springer.
Warrant, E. and Dacke, M. Vision and visual navigation in nocturnal insects. Annu Rev Entomol 56, 239‐54.