Shu-Ichi Watanabe

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In the mammalian retina, AII amacrine cells play a crucial role in scotopic vision. They transfer rod signals from rod bipolar cells to the cone circuit, and divide these signals into the ON and OFF pathways at the discrete synaptic layers. AII amacrine cells have been reported to generate tetrodotoxin (TTX)-sensitive repetitive spikes of small amplitude.(More)
In retinal ganglion cells (RGCs), the expression of various types of voltage-gated sodium channel (Nav) alpha-subunits (Nav1.1, Nav1.2, Nav1.3, and Nav1.6) has been reported. Like RGCs, certain subsets of retinal amacrine cells, including AII amacrine cells, generate tetrodotoxin (TTX)-sensitive action potentials in response to light; however, the Nav(More)
Compartmentalization of neuronal function is achieved by highly localized clustering of ion channels in discrete subcellular membrane domains. Voltage-gated potassium (Kv) channels exhibit highly variable cellular and subcellular patterns of expression. Here, we describe novel activity-dependent synaptic targeting of Kv4.2, a dendritic Kv channel, in(More)
Retinal amacrine cells are interneurons that make lateral and vertical connections in the inner plexiform layer of the retina. Amacrine cells do not possess a long axon, and this morphological feature is the origin of their naming. Their dendrites function as both presynaptic and postsynaptic sites. Half of all amacrine cells are GABAergic inhibitory(More)
BACKGROUND In university health care settings, students with psychosomatic complaints often have chronotypic problems. For this reason, we investigated a potential connection between psychosomatic complaints and circadian rhythm irregularity assessed by salivary levels of melatonin and growth hormone. METHODS Fifteen healthy students between 21 and 22(More)
In this study, we examined alterations in the enzymatic antioxidant defenses associated with learning deficits induced by type 2 diabetes, and studied the effects of the peroxisome proliferator-activated receptor γ agonist pioglitazone on these learning deficits. Learning ability was assessed by visual discrimination tasks in Otsuka Long-Evans Tokushima(More)
We generated self-induced retinal ganglion cells (RGCs) with functional axons from human induced pluripotent stem cells. After development of the optic vesicle from the induced stem cell embryoid body in three-dimensional culture, conversion to two-dimensional culture, achieved by supplementation with BDNF, resulted in differentiation of RGCs at a rate of(More)
BACKGROUND Students suffering from psychosomatic symptoms, including drowsiness and feelings of melancholy, often have basic lifestyle problems. The aim of this study was to investigate whether psychosomatic complaints may be related to circadian dysfunction. METHODS We examined 15 healthy students (4 men and 11 women) between 21 and 22 years old. To(More)
PURPOSE We previously generated self-induced retinal ganglion cells (RGCs) with functional axons from human induced pluripotent stem cells (hiPSCs). We investigated whether self-induced RGCs from mouse embryonic stem cells (mESCs) and induced pluripotent stem cells (miPSCs) are realized by the similar induction protocol. METHODS Retinal ganglion cells(More)
HPC-1/syntaxin 1A (STX1A) is abundantly expressed in neurons. STX1A is believed to regulate exocytosis in synaptic vesicles. In our recent studies, STX1A knockout (KO) mice showed normal development, and basal synaptic transmission in cultured hippocampal neurons appeared to be normal. However, behavioral abnormalities were observed in STX1A KO mice. In the(More)