Distinct Mammalian Precursors Are Committed to Generate Neurons with Defined Dendritic Projection Patterns

Abstract

The mechanisms that regulate how dendrites target different neurons to establish connections with specific cell types remain largely unknown. In particular, the formation of cell-type–specific connectivity during postnatal neurogenesis could be either determined by the local environment of the mature neuronal circuit or by cell-autonomous properties of the immature neurons, already determined by their precursors. Using retroviral fate mapping, we studied the lamina-specific dendritic targeting of one neuronal type as defined by its morphology and intrinsic somatic electrical properties in neonatal and adult neurogenesis. Fate mapping revealed the existence of two separate populations of neuronal precursors that gave rise to the same neuronal type with two distinct patterns of dendritic targeting—innervating either a deep or superficial lamina, where they connect to different types of principal neurons. Furthermore, heterochronic and heterotopic transplantation demonstrated that these precursors were largely restricted to generate neurons with a predetermined pattern of dendritic targeting that was independent of the host environment. Our results demonstrate that, at least in the neonatal and adult mammalian brain, the pattern of dendritic targeting of a given neuron is a cell-autonomous property of their precursors.

Speed control for neuronal migration in the postnatal brain by Gmip-mediated local inactivation of RhoA

“…5e,f), as previously reported 36,37 . To compare the arborizations, we determined the depth of the initial branch point, a surrogate measure of dendritic innervation patterns 37 , and found that the dendrites extending to the superficial EPL by the Gmip KD superficial GCs were similar to those of the control group ( Fig. 5e,f; for other dendrite measures, see Supplementary Fig.…”

“…In the GCL, GCs not only exhibit distinct morphologies and dendritic projection patterns from sub-layer to sub-layer, but also have different synaptic innervations and inhibitory functions for olfactory inputs 36,37 . We found that Gmip KD increased the percentage of new GCs distributed to the superficial layers of the GCL owing to the insufficient deceleration of migrating neurons in the OB, although the redistributed cells' dendritic morphology was similar to that of the naive superficial GCs (Fig.…”

“…5e,f; for other dendrite measures, see Supplementary Fig. 8) 36,37 . Thus, the redistributed neurons elaborated dendritic structures that were appropriate for the position of the soma.…”

Roles of Planar Cell Polarity Signaling in Maturation of Neuronal Precursor Cells in the Postnatal Mouse Olfactory Bulb

“…In addition, since impaired PCP signaling decreases NPC migration into the outer GCL (Fig. 2), it is possible that the altered morphology of the GCs, such as the longer primary dendrite, is partly due to their altered migration and localization [60]. Roles for Wnt signaling in neurite formation have been reported in invertebrates and vertebrates.…”

Development of Cerebellar GABAergic Interneurons: Origin and Shaping of the “Minibrain” Local Connections

“…In the cerebral cortex, different interneuron categories originate from defined subsets of subpallial progenitors, whose developmental potentialities depend on their location [62][63][64] and on the time of their generation [45, 65,66]. Finally, the production of olfactory bulb interneurons is sustained by separate progenitor pools, restricted in space [67][68][69][70] and time [71][72][73]. Thus, while the most common strategy to generate the variety of CNS interneurons relies on dedicated precursors that differentiate according to cell-intrinsic programs, those of the cerebellum are produced by naive progenitors under the influence of extrinsic instructive cues.…”