Development of Continuous and Discrete Neural Maps

Howard Hughes Medical Institute, Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
Neuron (Impact Factor: 15.98). 11/2007; 56(2):284-300. DOI: 10.1016/j.neuron.2007.10.014
Source: PubMed

ABSTRACT Two qualitatively different kinds of neural map have been described: continuous maps exemplified by the visual retinotopic map, and discrete maps exemplified by the olfactory glomerular map. Here, we review developmental mechanisms of retinotopic and olfactory glomerular mapping and discuss underlying commonalities that have emerged from recent studies. These include the use of molecular gradients, axon-axon interactions, and the interplay between labeling molecules and neuronal activity in establishing these maps. Since visual retinotopic and olfactory glomerular maps represent two ends of a continuum that includes many other types of neural map in between, these emerging general principles may be widely applicable to map formation throughout the nervous system.

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    • "The cellular and molecular mechanisms underlying many steps of mammalian brain circuit assembly have been explored in detail. Prominent examples include growth cone navigation through intermediate choice points (Dickson, 2002), topographic mapping (Luo and Flanagan, 2007; Cang and Feldheim, 2013), and laminar specificity (Huberman et al., 2010; Robles and Baier, 2012; Baier, 2013). Among the lesser understood steps involved in circuit assembly, however, is axon-target matching. "
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    Neuron 05/2015; 86(4). DOI:10.1016/j.neuron.2015.04.005 · 15.98 Impact Factor
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    • "In others, such as in the gustatory system, the arrangement corresponds to the qualities of the stimuli, such that similar stimuli are represented on nearby positions of the perceptual space. Not every topographic map is a continuous function according to modern usage of the term, although a continuous function satisfies the properties of a topographic map and historically they have been used synonymously (Luo & Flanagan, 2007). However, the same principles that guide the arrangement of neurons composing a topographic map also tend towards continuous functions. "
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    Proceedings of the 36th Annual Conference of the Cognitive Science Society, Austin, TX; 08/2014
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    • "Afferent pat-585 tern formation (termed map formation because of mapping 586 from parameter space unto neuronal space) has been more 587 easily studied in the sensory system (especially the visual). 588 The importance of chemical gradients (Sperry 1963) has been 589 well established in the retinotectal pathway with the presence 590 of two (ephrin and EphA receptors) linear countergradients 591 (Luo and Flanagan 2007) present in the afferents and in the 592 target cells, respectively. Nonlinear mapping as required for 593 higher-order TW could be conceivable by nonlinear interac-594 tions between the two gradients (Stettler et al. 2012). "
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