User:Eugene M. Izhikevich/Proposed/Direction selective cells

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Dr. William R. Levick accepted the invitation on 22 November 2009 (self-imposed deadline: 22 May 2010).
Figure 1: Your introductory color figure is here to "advertise" the article or summarize the main point.

In the visual system Direction Selective Cells are a class of neurons each of which selectively signals the direction in which objects move within the field of view. The concept of visual motion is based upon a coordinated variation of light intensity in both time and space in the environment. In the eye's retina this is detected by an array of photoreceptors that signal intensity only as a function of time at each position in the array. The signals are forwarded to successive arrays of neurons through particular discrete networks of ordered interconnections that provide the substrate for the property of directional selectivity. The subsets of neurons involved are drawn from three major classes of retinal neurons: bipolar cells; amacrine cells; ganglion cells. What distinguishes the subsets is the exclusive layering and confinement of their interconnections within thin sublaminae of the inner retina. It is widely accepted that the key neuron class in the mechanism of direction selectivity is the starburst amacrine cell. The architecture of its dendritic tree (surface receiving synaptic input) adds the critical space-time coordination lacking in individual photoreceptors. The remarkable series of discoveries that have uncovered most aspects of the mechanism provide an instructive example of what is required to understand neural computation in vivo.


Direction selective signaling

Everything that is ever seen in normal vision is encoded in the spike discharges of retinal ganglion cells. These are the output neurons of the retina. Their signals are transmitted by long nerve fibers in the optic nerves that connect the eyes with higher visual centers in the brain. There are numerous different classes of ganglion cells as revealed by striking differences of visual responsiveness to patterned visual stimuli.

Figure 2: Example of Direction Selectivity
Figure 1 shows the strikingly different responses when a spot of light is moved in opposite directions along the same path across a cell's receptive field, its localized patch of sensitivity in the external visual field.

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Refer to figures and equations as Figure 1 and Eq. (1).

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Subsection f

Citing references

Groups of authors larger than 2 can be cited with "et al.".

  • As proven in (Albero A, 1999).
  • As Albero (2009) said.
  • As proven in (Albero and Bocca, 2001)
  • As proven by Albero and Bocca (2001)
  • As proven by Albero et al. (2003)
  • As proven by Albero, Bocca and Cuoco (2003)
  • As proven by Albero et al. (2007a), confirmed by Albero et al. (2007b) and discarded by Albero et al. (2007c)
  • As proven in (Albero A, 1999).
  • As proven by Albero and Bocca (2001).


  • Albero, Antony (1999). Pizza Margherita. Journal of pizza eaters 19(3): 13. arXiv:0808.000
  • Albero(2001). Pizza Capricciosa. Journal of pizza eaters 27: 121-127. arXiv:0808.000
  • Albero, Antonio; Bocca, Bill and Cuoco, C T (2003). Pizza Quattro Stagioni. Journal of pizza eaters 34(4): 12.
  • Albero, Antonio; Bocca, Bill; Cuoco, C T and Dude, David B (2007a). Pizza Napoletana. Journal of pizza eaters 37: 121-127.
  • Albero, Antonio; Bocca, Bill; Cuoco, C T; Dude, David and Elica, E Q (2007b). Pizza Marinara. Journal of pizza eaters 43(4): 1-13.
  • Albero, Antonio et al. (2008). Pizza Piccante. Journal of pizza eaters 45(5): 1-13.
  • Alto, Antony (1999). La Pizza! Mangiare bene, Volume 3. Albero and Bacca editors. Food Publishers, Genoa.
  • Alto, Antony and Bocca, Bill (2000). La Pasta! Mangiare bene. Albero editor. Food Publishers, Genoa. Chapter 1.
  • Alto, Antony; Bocca, Bill and Cuoco, C T (2002). Pizza: prepare it yourself. Food Publishers, Genoa. Page 22. ISBN 1-234-99929-0.
  • Alto, Antony; Bocca, Bill; Cuoco, C T and Dude, David B (2005a). Italian Pizza. Food Publishers, Genoa.
  • Alto, Antony; Bocca, Bill; Cuoco, C T; Dude, David B and Elica, E Q (2005b). Napolitan Pizza. Food Publishers, Genoa.
  • Alto, Antony et al. (2005c). American Pizza. Food Publishers, Genoa.

Further reading

  • Magro, C T (2008). Pizza: a danger for health? Food Publishers, Paris. page 22. ISBN 1-234-90929-0. This reference is unreliable in conclusions, but quite accurate in its introduction.
  • Izhikevich, E M (2007). Dynamical Systems in Neuroscience: The Geometry of Excitability and Bursting The MIT Press, Cambridge, MA. ISBN 0262090430. This book offers an introduction to nonlinear dynamical systems theory for researchers and graduate students in neuroscience.

External links

Eugene M. Izhikevich website

See also

Brain, Neuron, Scholarpedia:Instructions for authors

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