TY - JOUR
T1 - Altered molecular regionalization and normal thalamocortical connections in cortex-specific Pax6 knock-out mice
AU - Piñon, Maria Carmen
AU - Tran, Cong Tuoc
AU - Ashery-Padan, Ruth
AU - Molnár, Zoltán
AU - Stoykova, Anastassia
PY - 2008/8/27
Y1 - 2008/8/27
N2 - Transcription factor Pax6 exerts a prominent rostrolateral high to caudomedial low expression gradient in the cortical progenitors and have been implicated in regulation of area identity in the mammalian cortex. Herein, we analyzed the role of Pax6 in molecular arealization and development of thalamocortical connections in the juvenile cortex-specific conditional Pax6 knock-out mice (Pax6cKO). Using a set of molecular markers of positional identity (Id2, Cadherin6, COUP-TF1, RZRβ, and EphA7), we show that, in the juvenile Pax6cKO, the relative size of caudal cortical areas (putative visual and somatosensory) are mildly enlarged, whereas the rostral domain (putative motor) is severely reduced. Despite the rostral shift of graded expression of areal markers, the distribution of area-specific thalamocortical and corticofugal projections appear normal in the Pax6cKO. This indicates that change of the size of cortical areas is not accompanied by a change in cortical identity. We show furthermore that, despite a severe depletion of supragranular cortical layers and accumulation of cells along the pallial-subpallial boundary, thalamocortical fibers establish a periphery-related pattern of the somatosensory cortex in normal position in Pax6cKO. Our findings indicate that Pax6 expression gradients in cortical progenitors do not directly impart thalamocortical or corticofugal areal identity.
AB - Transcription factor Pax6 exerts a prominent rostrolateral high to caudomedial low expression gradient in the cortical progenitors and have been implicated in regulation of area identity in the mammalian cortex. Herein, we analyzed the role of Pax6 in molecular arealization and development of thalamocortical connections in the juvenile cortex-specific conditional Pax6 knock-out mice (Pax6cKO). Using a set of molecular markers of positional identity (Id2, Cadherin6, COUP-TF1, RZRβ, and EphA7), we show that, in the juvenile Pax6cKO, the relative size of caudal cortical areas (putative visual and somatosensory) are mildly enlarged, whereas the rostral domain (putative motor) is severely reduced. Despite the rostral shift of graded expression of areal markers, the distribution of area-specific thalamocortical and corticofugal projections appear normal in the Pax6cKO. This indicates that change of the size of cortical areas is not accompanied by a change in cortical identity. We show furthermore that, despite a severe depletion of supragranular cortical layers and accumulation of cells along the pallial-subpallial boundary, thalamocortical fibers establish a periphery-related pattern of the somatosensory cortex in normal position in Pax6cKO. Our findings indicate that Pax6 expression gradients in cortical progenitors do not directly impart thalamocortical or corticofugal areal identity.
KW - Arealization
KW - Connections
KW - Cortex
KW - Mouse
KW - Pax6
KW - Thalamus
UR - http://www.scopus.com/inward/record.url?scp=52049118292&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.2565-08.2008
DO - 10.1523/JNEUROSCI.2565-08.2008
M3 - מאמר
AN - SCOPUS:52049118292
VL - 28
SP - 8724
EP - 8734
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 35
ER -