Moritoshi Hirono

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After opening in response to mechanical stimuli, hair cell transduction channels adapt with fast and slow mechanisms that each depend on Ca(2+). We demonstrate here that transduction and adaptation require phosphatidylinositol 4,5-bisphosphate (PIP(2)) for normal kinetics. PIP(2) has a striking distribution in hair cells, being excluded from the basal(More)
Noradrenaline (NA) modulates synaptic transmission in various sites of the CNS. In the cerebellar cortex, several studies have revealed that NA enhances inhibitory synaptic transmission by beta-adrenoceptor-and cyclic AMP-dependent pathways. However, the effects of alpha-adrenoceptor activation on cerebellar inhibitory neurotransmission have not yet been(More)
In sensory hair cells of the inner ear, mechanical amplification of small stimuli requires fast adaptation, the rapid closing of mechanically activated transduction channels. In frog and mouse vestibular hair cells, we found that the rate of fast adaptation depends on both channel opening and stimulus size and that it is modeled well as a release of a(More)
Ethanol (EtOH) modulates synaptic efficacy in various brain areas, including the cerebellum, which plays a role in motor coordination. Previous studies have shown that EtOH enhances tonic inhibition of cerebellar granule cells, which is one of the possible reasons for the alcohol-induced motor impairment. However, the effects of EtOH on molecular layer(More)
Noradrenaline (NA) modulates glutamatergic and GABAergic transmission in various areas of the brain. It is reported that some alpha2-adrenoceptor subtypes are expressed in the cerebellar cortex and alpha2-adrenoceptors may play a role in motor coordination. Our previous study demonstrated that the selective alpha2-adrenoceptor agonist clonidine partially(More)
Inhibitory interneurons in the cerebellar granular layer are more heterogeneous than traditionally depicted. In contrast to Golgi cells, which are ubiquitously distributed in the granular layer, small fusiform Lugaro cells and globular cells are located underneath the Purkinje cell layer and small in number. Globular cells have not been characterized(More)
From the ‡Department of Molecular Neurobiology, Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, the ¶Department of Molecular Neurobiology, School of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa-shi, Saitama 359-1192, the Laboratory of Neurobiophysics, School of(More)
The purpose of this study is to ascertain whether or not prostaglandins (PGs) act directly on the pituitary. In the first experiment, the plasma LH levels were sharply decreased 24 hr after the production of hypothalamic lesions in ovariectomized mature rats. Ten min after the iv injection of PGE1, PGE2 or PGF2alpha, the plasma LH levels increased(More)
The structural maintenance of neural circuits is critical for higher brain functions in adulthood. Although several molecules have been identified as regulators for spine maintenance in hippocampal and cortical neurons, it is poorly understood how Purkinje cell (PC) spines are maintained in the mature cerebellum. Here we show that the calcium channel type 1(More)
gamma-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter and also presumed to be a neurotrophic factor. GABA is synthesized by glutamate decarboxylase (GAD). A mouse lacking a 67kDa isoform of GAD (GAD67) has a reduced GABA level in its brain at birth and does not survive postnatally because of cleft palate. In this study, to investigate the(More)