Masahumi Kawaguchi

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Vertebrate brains exhibit vast amounts of anatomical diversity. In particular, the elaborate and complex nervous system of amniotes is correlated with the size of their behavioral repertoire. However, the evolutionary mechanisms underlying species-specific brain morphogenesis remain elusive. In this review we introduce reptiles as a new model organism for(More)
The generation of complex neural circuits depends on the correct wiring of neurons with diverse individual characteristics. To understand the complexity of the nervous system, the molecular mechanisms for specifying the identity and diversity of individual neurons must be elucidated. The clustered protocadherins (Pcdh) in mammals consist of approximately 50(More)
In the brain, enormous numbers of neurons have functional individuality and distinct circuit specificities. Clustered Protocadherins (Pcdhs), diversified cell-surface proteins, are stochastically expressed by alternative promoter choice and affect dendritic arborization in individual neurons. Here we found that the Pcdh promoters are differentially(More)
The cadherin-related neuronal receptor (CNR)/protocadherin (Pcdh) alpha family is one of the diverse protocadherin families expressed in developing axons. We observed a strong axonal expression of these proteins at late embryonic and early postnatal stages corresponding to regions where fibers had not yet been myelinated. We therefore followed the postnatal(More)
The trigeminal circuit relays somatosensory input from the face into the central nervous system. In central nuclei, the spatial arrangement of neurons reproduces the physical distribution of peripheral receptors, thus generating a somatotopic facial map during development. In mice, the ophthalmic, maxillary, and mandibular trigeminal nerve branches maintain(More)
The spinal nerve, which is composed of dorsal root ganglion (DRG) sensory axons and spinal motor axons, forms the dorsal ramus projecting to the dorsal musculature. By using the free-floating immunohistochemistry method, we closely examined the spatiotemporal pattern of the formation of the dorsal ramus and the relationship between its projection to the(More)
BACKGROUND AND OBJECTIVE Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the(More)
During vertebrate development, the central nervous system (CNS) has stereotyped neuronal tracts (scaffolds) that include longitudinal and commissural axonal bundles, such as the medial longitudinal fascicle or the posterior commissure (PC). As these early tracts appear to guide later-developing neurons, they are thought to provide the basic framework of(More)
We report habenular lateralization in a simple transgenic mouse model used for labeling a facet of neuronal activity history. A transgenic construct comprised of a zif268/egr1 immediate-early gene promoter and a gene for normal Venus fluorescent protein with a membrane tag converted promoter activity into long-life fluorescent proteins, which was thought to(More)
With the exception of that from the olfactory system, the vertebrate sensory information is relayed by the dorsal thalamus (dTh) to be carried to the telencephalon via the thalamo-telencephalic tract. Although the trajectory of the tract from the dTh to the basal telencephalon seems to be highly conserved among amniotes, the axonal terminals vary in each(More)