Cortical Spiny Stellate Cell

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Spiny Stellate Cell is a neuron in mammals.

Figure 1: The cortical layers.

Location in visual cortex

Spiny stellate cells are found in the primary visual cortex (V1, area 17), which is located in the occipital lobe.

Figure 1 shows the cortical layers of the primary visual cortex as defined by Brodmann using Nissl stains. Spiny stellate cells are primarily found in layer 4C, which is farther divided into 4Cα and 4Cβ. The dendritic tree of spiny stellate cells is confined to layer IV.

Anatomy

As the name suggests, these cells are star-shaped and have spiny dendrites, which means that their dendrites contain dendritic spines. These spines can receive synaptic input. Spiny stellate cells are excitatory cells.

In rodent somatosensory cortex, spiny stellate neurons can be either symmetrical or assymetrical. A symmetrical cell has a dendritic tree that is polarized towards the center of the whisker barrel.

They lack an apical dendrite, which is a long dendrite that extends to layer I, where it has many branches. The axon contains boutons. The spiny stellate neuron has shorter dendrites and axon than the other two main cells found in layer IV, which are star pyramidal cells and pyramidal cells.

Input

Spiny stellate cells in cortical layer 4C receive input from the magnocellular LGN. There are few spiny stellate cells in layer 4B, which only receive input from cells in layer 4Cα. They tend to receive synaptic inputs from the same barrel, which indicates that spiny stellate cells focus mainly on local processing.

Projections

Spiny stellate neurons in primary visual cortex project mainly to area MT of the brain. In somatosensory cortex, their axons project in same barrel and generally connect with other Layer IV spiny neurons and sometimes with Layer 2/3 pyramidal cells. They do not generally connect with neurons in other barrels.

References

1. Bear, Mark F.; Connors, Barry W.; and Paradiso, Micheal A. Neuroscience: Exploring the Brain. Lippincott, Williams, & Wilkins: Maryland; 2001.

2. Lübke, J., A. Roth, D. Feldmeyer, and B. Sackmann. "Morphometric analysis of the columnar innervation domain of neurons connecting layer 4 and layer 2/3 of juvenile rat barrel cortex." Cereb Cortex. 13 Oct. 2003. Web. 24 Aug. 2009. [1].

3. Nassi, Jonathan J., and Edward M. Callaway. "Specialized Circuits from Primary Visual Cortex to V2 and Area MT." NIH Public Access. 17 Aug. 2009. Web. 23 Aug. 2009. [2].

4. Schmolesky, Matthew. "The Primary Visual Cortex." Webvision: The Organization of the Retina and Visual System. Kolb, Helga; Fernandez, Eduardo; Nelson, Ralph, Dec. 2000. Web. 23 Aug. 2009. [3].

5. Schubert, D., R. Kötter, K. Zilles, H.J. Luhmann, and J.F. Staiger. "Cell type-specific circuits of cortical layer IV spiny neurons." J Neurosci. 1 Apr. 2003. Web. 23 Aug. 2009. [4].

6. Staiger, JF, I. Flagmeyer, D. Schubert, K. Zilles, R. Kötter, and HD Luhmann. "Functional diversity of layer IV spiny neurons in rat somatosensory cortex: quantitative morphology of electrophysiologically characterized and biocytin labeled cells." Cereb Cortex. 28 Mar. 2004. Web. 23 Aug. 2009. [5].

Additional information

  1. The Primary Visual Cortex
  2. NeuroLex Neocortex_stellate_spiny_cell
  3. NeuroLex Spiny_stellate_cell