Difference between revisions of "W3 Cell"

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== Molecules ==
 
== Molecules ==
  
Until recently, few if any molecular markers were available to identify these RGC subtypes, so most analyses depended on nonselective labeling methods. Likewise, many developmental studies have treated RGCs as a single population. This limitation severely compromises analysis of RGC projections and development. For example, it is difficult to learn whether subtypes develop in distinct ways if they can be identified only after they have matured.This problem is now being circumvented in mice by generation of genetically engineered lines in which RGC subsets are marked with reporter genes (Hattar et al., 2002; Kim et al., 2008<ref name="Kim2008">{{cite journal  | author=In-Jung Kim; Yifeng Zhang; Markus Meister; Joshua R. Sanes |title=Laminar Restriction of Retinal Ganglion Cell Dendrites and Axons: Subtype-Specific Developmental Patterns Revealed with Transgenic Markers  |journal=J.Neurosci. |volume=30 |issue=4 |pages=1452-1462  |year=2010 |doi=10.1523/​JNEUROSCI.4779-09.2010 }}</ref>; Yonehara et al., 2008; Badea et al., 2009; Huberman et al., 2009; Siegert et al., 2009). Here, we characterize the structure and function of RGCs marked in four transgenic lines, then use them to address a set of open questions about patterning and development of axonal and dendritic arbors:
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Until recently, few if any molecular markers were available to identify these RGC subtypes, so most analyses depended on nonselective labeling methods. Likewise, many developmental studies have treated RGCs as a single population. This limitation severely compromises analysis of RGC projections and development. For example, it is difficult to learn whether subtypes develop in distinct ways if they can be identified only after they have matured.This problem is now being circumvented in mice by generation of genetically engineered lines in which RGC subsets are marked with reporter genes (Hattar et al., 2002; Kim et al., 2008<ref name="Kim2008">{{cite journal  | author=In-Jung Kim; Yifeng Zhang; Markus Meister; Joshua R. Sanes |title=Laminar Restriction of Retinal Ganglion Cell Dendrites and Axons: Subtype-Specific Developmental Patterns Revealed with Transgenic Markers  |journal=J.Neurosci. |volume=30 |issue=4 |pages=1452-1462  |year=2010 |doi=10.1523/​JNEUROSCI.4779-09.2010 |url=http://www.jneurosci.org/content/30/4/1452.full.pdf }}</ref>; Yonehara et al., 2008; Badea et al., 2009; Huberman et al., 2009; Siegert et al., 2009). Here, we characterize the structure and function of RGCs marked in four transgenic lines, then use them to address a set of open questions about patterning and development of axonal and dendritic arbors:
  
 
== History ==
 
== History ==

Revision as of 16:41, 30 March 2012

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A W3 cell in connection with a few different types of amacrine cells.

Until relatively recently, it was thought that the receptive fields of retinal ganglion cells were one of two center-surround receptive field types (either OFF-center, ON-surround or ON-center, OFF-surround). Within the last decade, however, it has become increasingly clear that the notion that only two types of receptive fields exist in photoreceptors is a gross oversimplification. Scientists now know that ganglion cells come in at least 15 or 20 types, each of which has a distinct shape and physiological function, and which correspondingly has connections with different types of cells in the rest of the retina. Further, each of these different ganglion cell types has a distinctive receptive field. Together, the receptive fields of all of the different cell types form an array that allows individuals to perceive all properties of the entire visual field. Specific cell types are distinct from one another in the sense that they respond to different visual properties than other cells: it is therefore the summation of input coming from all of the different types of retinal ganglion cells that allows an individual to completely visually perceive something . In order to develop a more comprehensive understanding of the retina, researchers are trying not only to identify the different retinal cell types (i.e. to explicitly classify the 15 or 20 types), but also to identify what image operation each type of retinal ganglion cell reports.

One example of a retinal ganglion cell type with specific visual response properties is the W3 retinal ganglion cell, which has been identified in the mouse retina. W3 is considered the equivalent to the object motion selective (OMS) ganglion cell in salamanders. Because relatively little work has been done specifically on W3 and a fair amount has been done regarding connections and properties of OMS, some of the information in the article will be about OMS.


Physiology

OMS and W3 both respond sensitively to differential motion between the receptive field center and surround, as produced by an object moving over the background, but are strongly suppressed by global image motion, as produced by the observer’s head or eye movements.

Anatomy

W3 cells have small cell body and small arbors that are densely branched. Typically, the diameter of their dendritic field is about 120 microns. The arbors occupy a thick swath in the middle of the IPL from sublayer4 (SL4) through SL6 with minor sprouts arborization in SL1, when the IPL is divided into 10 imaginary strata. The region from SL4 to SL6 lies between the ON and OFF ChAT bands.

Location

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Rough visualization of the stratification of W3 cell, occupying approximately 2.5/10 sublayers from the INL side.

Shape

Connections

Molecules

Until recently, few if any molecular markers were available to identify these RGC subtypes, so most analyses depended on nonselective labeling methods. Likewise, many developmental studies have treated RGCs as a single population. This limitation severely compromises analysis of RGC projections and development. For example, it is difficult to learn whether subtypes develop in distinct ways if they can be identified only after they have matured.This problem is now being circumvented in mice by generation of genetically engineered lines in which RGC subsets are marked with reporter genes (Hattar et al., 2002; Kim et al., 2008[1]; Yonehara et al., 2008; Badea et al., 2009; Huberman et al., 2009; Siegert et al., 2009). Here, we characterize the structure and function of RGCs marked in four transgenic lines, then use them to address a set of open questions about patterning and development of axonal and dendritic arbors:

History

Open Questions and Relevance to the EyeWire Project

References

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