Transcription factors with gradients of expression in neocortical progenitors give rise to distinct motor and sensory cortical areas by controlling the area-specific differentiation of distinct neuronal subtypes. However, the molecular mechanisms underlying this area-restricted control are still unclear. Here, we show that COUP-TFI controls the timing of birth and specification of corticospinal motor neurons (CSMN) in somatosensory cortex via repression of a CSMN differentiation program. Loss of COUP-TFI function causes an area-specific premature generation of neurons with cardinal features of CSMN, which project to subcerebral structures, including the spinal cord. Concurrently, genuine CSMN differentiate imprecisely and do not project beyond the pons, together resulting in impaired skilled motor function in adult mice with cortical COUP-TFI loss-of-function. Our findings indicate that COUP-TFI exerts critical areal and temporal control over the precise differentiation of CSMN during corticogenesis, thereby enabling the area-specific functional features of motor and sensory areas to arise.arealization | subcerebral projection neurons | neocortex development | corticofugal neurons | nuclear receptor | behavior T he mammalian cerebral cortex, responsible for fine motor control and sensorimotor integration, is subdivided into functionally distinct areas that control motor functions and process distinct sensory modalities (1). Individual areas are distinguished by their cytoarchitecture, connectivity, physiology, and patterns of gene expression (2, 3). Each area is radially divided into six layers, and each layer consists of a variety of populations of neurons with distinctive morphologies, connectivity, and developmental programs of gene expression (4-9). In particular, layers VI and V contain corticofugal neurons, which send their axons to deep brain structures, such as the thalamus (corticothalamic neurons), the striatum (corticostriatal neurons), pons (corticopontine neurons), tectum (corticotectal neurons), and spinal cord (corticospinal motor neurons, CSMN) (7).The fate of neurons and laminar cytoarchitecture in each specific area determines their function: the adult primary motor cortex contains a large number of CSMN and has a thick layer V; the primary somatosensory area is characterized by a thick layer IV, where the neurons that receive relayed sensory inputs are located (10). The area-specific differences in neuronal fate and cytoarchitecture have been thought to result from late postmitotic events, e.g. selective postnatal pruning of axons (11), and premitotic events, such as the timing, rate, and duration of proliferation of precursors producing distinct projection neuron subtypes (12-16). As a striking illustration of such processes, CSMN are generated at a higher rate in the developing motor cortex than in sensory areas in mice (12), but the molecular mechanisms that control this area-specific differential production of CSMN are not known. The transcription factor COUP-TFI is particularly interestin...

Solvatisiertes Solvens: Wassermoleküle wechselwirken mit dem Imidazoliumkation und dem [BF4]−‐Ion (siehe Bild) des flüssigen Salzes 1‐n‐Butyl‐3‐methylimidazolium‐tetrafluoroborat. Kern‐Overhauser‐Effekte in den 1H{1H}‐ und 1H{19F}‐NMR‐Spektren weisen auf kurze C‐H⋅⋅⋅O‐ und C‐H⋅⋅⋅F‐Wasserstoffbrücken hin.

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Most of the research on ventral striatal functions has been focused on their role in modulating reward and motivation. More recently, a possible role of this structure in cognitive functions has been suggested. However, very little information is available on the involvement of the nucleus accumbens in the different stages of the consolidation process. In this study, the effect of focal injections of AP-5 and DNQX, competitive antagonists at the NMDA and AMPA receptors, respectively, was examined in a nonassociative task designed to estimate the ability of mice to react to spatial changes. The task consists of placing the animals in an open field containing five objects; after three sessions of habituation, their reactivity to object displacement was examined 24 hr later.AP-5 injections administered after training impaired the ability of mice to detect the spatial novelty but did not affect response when injected 120 min after training or before testing. On the contrary, DNQX did not affect response when administered immediately or 120 min after training but did impair spatial discrimination when administered before training or testing. These data demonstrate a double dissociation between glutamate receptor subtypes, such that accumbens NMDA receptors are important for consolidation and not ongoing discrimination of spatial information, whereas AMPA receptors have an opposite role in these processes.

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