First Author | Joshi PS | Year | 2008 |
Journal | Neuron | Volume | 60 |
Issue | 2 | Pages | 258-72 |
PubMed ID | 18957218 | Mgi Jnum | J:144066 |
Mgi Id | MGI:3829845 | Doi | 10.1016/j.neuron.2008.08.006 |
Citation | Joshi PS, et al. (2008) Bhlhb5 regulates the postmitotic acquisition of area identities in layers II-V of the developing neocortex. Neuron 60(2):258-72 |
abstractText | While progenitor-restricted factors broadly specify area identities in developing neocortex, the downstream regulatory elements involved in acquisition of those identities in postmitotic neurons are largely unknown. Here, we identify Bhlhb5, a transcription factor expressed in layers II-V, as a postmitotic regulator of area identity. Bhlhb5 is initially expressed in a high caudomedial to low rostrolateral gradient that transforms into a sharp border between sensory and rostral motor cortices. Bhlhb5 null mice exhibit aberrant expression of area-specific genes and structural organization in the somatosensory and caudal motor cortices. In somatosensory cortex, Bhlhb5 null mice display postsynaptic disorganization of vibrissal barrels. In caudal motor cortex, Bhlhb5 null mice exhibit anomalous differentiation of corticospinal motor neurons, accompanied by failure of corticospinal tract formation. Together, these results demonstrate Bhlhb5's function as an area-specific transcription factor that regulates the postmitotic acquisition of area identities and elucidate the genetic hierarchy between progenitors and postmitotic neurons driving neocortical arealization. |