patterned firing will result in stronger connectivity within the retinotopic organization through NMDAR synapse stabilization mechanisms in the post synaptic cells. Dynamic Growth Another important factor in the development of retinotopy is the potential for structural plasticity even after neurons are morphologically mature. One interesting hypothesis is that axons and dendrites are continuously extending and retracting their axons and dendrites. Several factors alter this dynamic growth including the Chemoaffinity Hypothesis, the presence of developed synapses, and neural activity. As the nervous system develops and more cells are added, this structural plasticity allows for axons to gradually refine their place within the retinotopy. This plasticity is not specific to retinal ganglion axons, rather it's been shown that dendritic arbors of tectal neurons and filopodial processes of radial glial cells are also highly dynamic. Description In many locations within the brain, adjacent neurons have receptive fields that include slightly different, but overlapping portions of the visual field. The position of the center of these receptive fields forms an orderly sampling mosaic that covers a portion of the visual field. Because of this orderly arrangement, which emerges from the spatial specificity of connections between neurons in different parts of the visual system, cells in each structure can be seen as contributing to a map of the visual field (also called a retinotopic map, or a visuotopic map). Retinotopic maps are a particular case of topographic organization. Many brain structures that are responsive to visual input, including much of the visual cortex and visual nuclei of the brain stem (such as the superior colliculus) and thalamus (such as the lateral geniculate nucleus and the pulvinar), are organized into retinotopic maps, also called visual field maps. Areas of the visual cortex are sometimes defined by their retinotopic boundaries, using a criterion that states that each area should contain a complete map of the visual field. However, in practice the application of this criterion is in many cases difficult. Those visual areas of the brainstem and cortex that perform the first steps of processing the retinal image tend to be organized according to very precise retinotopic maps. The role of retinotopy in other areas, where neurons have large receptive fields, is still being investigated. Retinotopy mapping shapes the folding of the cerebral cortex. In both the V1 and V2 areas of macaques and humans the vertical meridian of their visual field tends to be represented on