Carina Hanashima

During mammalian cerebral corticogenesis, progenitor cells become progressively restricted in the types of neurons they can produce. The molecular mechanism that determines earlier versus later born neuron fate is unknown. We demonstrate here that the generation of the earliest born neurons, the Cajal-Retzius cells, is suppressed by the telencephalic transcription factor Foxg1. In Foxg1 null mutants, we observed an excess of Cajal-Retzius neuron production in the cortex. By conditionally inactiv

The winged helix gene Brain factor-1 (BF1) has a pleiotropic role in the development of the cerebral hemispheres of the brain. Mice lacking BF1 have defects in the morphogenesis of the structures of the dorsal telencephalon (e.g., neocortex) and the ventral telencephalon (e.g., the basal ganglia). This study focuses on the functions of BF1 in the dorsal telencephalon. We showed previously that telencephalic progenitor cells lacking BF1 differentiate into neurons prematurely. Here, we demonstrate

Cajal-Retzius (CR) cells, the earliest-born neurons in the neocortex, arise from discrete sources within the telencephalon, including the dorsal midline and the pallial-subpallial boundary (PSB). In particular, the cortical hem, a region of high bone morphogenetic proteins (BMPs) and Wnt (wingless-type MMTV integration site family) expression but lacking in Foxg1 (forkhead box G1) is a major source of CR neurons. Whether CR cells from distinct origins arise from disparate developmental processes

Among the forkhead box protein family, Foxg1 is a unique transcription factor that plays pleiotropic and non-redundant roles in vertebrate brain development. The emergence of the telencephalon at the rostral end of the neural tube and its subsequent expansion that is mediated by Foxg1 was a key reason for the vertebrate brain to acquire higher order information processing, where Foxg1 is repetitively used in the sequential events of telencephalic development to control multi-steps of brain circu

Forkhead Box G1 (<i>FOXG1</i>) is a member of the Forkhead family of genes with non-redundant roles in brain development, where alteration of this gene's expression significantly affects the formation and function of the mammalian cerebral cortex. <i>FOXG1</i> haploinsufficiency in humans is associated with prominent differences in brain size and impaired intellectual development noticeable in early childhood, while homozygous mutations are typically fatal. As such, <i>FOXG1</i> has been implica

Information processing in the cerebral cortex requires the activation of diverse neurons across layers and columns, which are established through the coordinated production of distinct neuronal subtypes and their placement along the three-dimensional axis. Over recent years, our knowledge of the regulatory mechanisms of the specification and integration of neuronal subtypes in the cerebral cortex has progressed rapidly. In this review, we address how the unique cytoarchitecture of the neocortex

The functional integrity of the neocortical circuit relies on the precise production of diverse neuron populations and their assembly during development. In recent years, extensive progress has been made in the understanding of the mechanisms that control differentiation of each neuronal type within the neocortex. In this review, we address how the elaborate neocortical cytoarchitecture is established from a simple neuroepithelium based on recent studies examining the spatiotemporal mechanisms o

The development of a multicellular organism involves time-dependent changes in molecular and cellular states; therefore 'time' is an indispensable mathematical parameter of ontogenesis. Regardless of their inextricable relationship, there is a limited number of events for which the output of developmental phenomena primarily uses temporal cues that are generated through multilevel interactions between molecules, cells, and tissues. In this review, we focus on neural stem cells, which serve as a

Normal mammalian vitreous humor maintains its avascularity after regression of hyaloid vessels. Neovascularization in adults is only detected under pathological conditions which suggests that antiangiogenic factors are present in the vitreous humor. To elucidate the mechanism of vitreal angiogenic inhibition, we investigated the effect of vitreous humor on cultured vascular endothelial cells. When bovine aortic endothelial cells were cultured in the presence of bovine vitreous humor in medium, a

Odor information processing begins in the olfactory epithelium (OE), which in mice is spatially divided into two zones: the dorsomedial zone (D-zone), responsible for innate aversive behaviors, and the ventrolateral zone (V-zone), associated with learning-dependent behaviors. This zonal organization provides the structural framework for olfactory circuit function. However, the mechanisms driving OE zonal specification remain unclear. To investigate the initial segregation of the OE zones, we exa

During development, cell-intrinsic and cell-extrinsic factors play important roles in neuronal differentiation; however, the underlying mechanisms in nonmammalian species remain largely unknown. We here investigated the mechanisms responsible for the differentiation of sensory input neurons in the chick entopallium, which receives its primary visual input via the tectofugal pathway from the nucleus rotundus. The results obtained revealed that input neurons in the entopallium expressed Potassium

Ascorbic acid (AsA) is highly concentrated in vitreous in bovine, human as well as in other species. In order to evaluate the role of ascorbic acid as an ocular neovascularization inhibitor, we examined the effect of ascorbic acid on growth and survival of cultured vascular endothelial cells. When added to culture medium, high concentration of ascorbic acid (0.3 mM<) reduced viability of bovine aortic endothelial cells (BAEC) within 24 hr. Morphology of ascorbic acid treated endothelial cells de

A central question in developmental biology is how cells generate and sense information to form complex but reproducible patterns. Any given phenomenon in development involves time-dependent changes in states. Moreover, several developmental events rely on temporal cues to generate specific outputs, where time itself can contribute to create cell diversity and coordinated patterns. How the time information is encoded and how developmental system decipher such temporal codes, however, are long-st