A Novel Taulacz Allele Reveals A Requirement For Pitx2 In Formation Of The Mammillothalamic Tract, Mindy Waite
Dec 2011
A Novel Taulacz Allele Reveals A Requirement For Pitx2 In Formation Of The Mammillothalamic Tract, Mindy Waite
Mindy Waite
The hypothalamic mammillary region is critical for spatial memory and vestibular processing. Pitx2 encodes a paired-like transcription factor that is highly expressed in the developing mammillary region and is required for subthalamic nucleus formation. Here we analyzed a loss of function Pitx2-TaulacZ knock-in allele to study the effects of Pitx2 deficiency on neuronal projections in the embryonic mammillary region. Pitx2-expressing neurons contribute axons to principal mammillary, mammillotegmental and mammillotectal tracts. Embryos with Pitx2 deficiency exhibit axonal fibers in the principal mammillary tract that are improperly bundled and disorganized, yet project caudally toward the tectum and tegmentum. Embryos …
Distinct Populations Of Gabaergic Neurons In Mouse Rhombomere 1 Express But Do Not Require The Homeodomain Transcription Factor Pitx2, Mindy Waite
Dec 2011
Distinct Populations Of Gabaergic Neurons In Mouse Rhombomere 1 Express But Do Not Require The Homeodomain Transcription Factor Pitx2, Mindy Waite
Mindy Waite
Hindbrain rhombomere 1 (r1) is located caudal to the isthmus, a critical organizer region, and rostral to rhombomere 2 in the developing mouse brain. Dorsal r1 gives rise to the cerebellum, locus coeruleus, and several brainstem nuclei, whereas cells from ventral r1 contribute to the trochlear and trigeminal nuclei as well as serotonergic and GABAergic neurons of the dorsal raphe. Recent studies have identified several molecular events controlling dorsal r1 development. In contrast, very little is known about ventral r1 gene expression and the genetic mechanisms regulating its formation. Neurons with distinct neurotransmitter phenotypes have been identified in ventral r1 …
Gabaergic And Glutamatergic Identities Of Developing Midbrain Pitx2 Neurons, Mindy Waite
Jan 2011
Gabaergic And Glutamatergic Identities Of Developing Midbrain Pitx2 Neurons, Mindy Waite
Mindy Waite
Pitx2, a paired-like homeodomain transcription factor, is expressed in post-mitotic neurons within highly restricted domains of the embryonic mouse brain. Previous reports identified critical roles for PITX2 in histogenesis of the hypothalamus and midbrain, but the cellular identities of PITX2-positive neurons in these regions were not fully explored. This study characterizes Pitx2 expression with respect to midbrain transcription factor and neurotransmitter phenotypes in mid-to-late mouse gestation. In the dorsal midbrain, we identified Pitx2-positive neurons in the stratum griseum intermedium (SGI) as GABAergic and observed a requirement for PITX2 in GABAergic differentiation. We also identified two Pitx2-positive neuronal populations in the …
Influence Of Perinatal Exposure To A Polychlorinated Biphenyl Mixture On Learning And Memory, Hippocampal Size, And Estrogen Receptor-Beta Expression, Howard Cromwell
Dec 2009
Influence Of Perinatal Exposure To A Polychlorinated Biphenyl Mixture On Learning And Memory, Hippocampal Size, And Estrogen Receptor-Beta Expression, Howard Cromwell
Howard Casey Cromwell
Abstract. Perinatal exposure to PCB has been reported to cause a variety of health effects including endocrine disruption, and immunologic, reproductive, neurologic, and behavioral deficits. In the present study, a mixture of two PCB congeners, one non-coplanar (PCB 47) and one coplanar (PCB 77), were administered to young female Sprague-Dawley rats by route of maternal dietary consumption (either 12.5 ppm or 25.0 ppm, w/w). Impact on learning and memory were examined by radial arm maze on postnatal day 24-27. After behavioral tests were completed, the rats were transcardially perfused, and brains were excised. Immunohistochemistry for ER- β was carried out …
