Publications by authors named "Maya Yamazaki"

Familial advanced sleep phase (FASP) is a heritable human sleep trait characterized by early sleep onset and offset times. We have identified five variants in five different families in the human voltage-gated calcium channel subunit alpha1 D () that cosegregate with FASP. The variants in lead to altered channel dynamics in vitro.

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  • - Our brain adjusts to seasonal changes, but misadapting can lead to seasonal psychiatric disorders, particularly winter depression linked to specific gene variants in the circadian clock gene PERIOD3 (PER3).
  • - Two specific variants, P415A and H417R, were found to cause winter depression-like behaviors in male mice, linked to how these variants affect the adrenal gland's function.
  • - These variants disrupt the normal downregulation of corticosterone levels during shorter days, leading to increased glucocorticoid signaling, which then reduces serotonin production and contributes to depressive behaviors.
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  • Developmental synapse elimination is essential for forming mature neural circuits, particularly in the cerebellum of neonatal mice where Purkinje cells initially connect with multiple climbing fibers.
  • By postnatal day 20, all climbing fiber synapses except one are eliminated, with heterosynaptic interactions between climbing fibers and parallel fibers playing a key role in this process.
  • The study finds that the deletion of AMPA receptors in granule cells disrupts the elimination of climbing fiber synapses, highlighting the importance of parallel fiber activity, which may enhance synapse elimination by activating mGlu1 receptors in Purkinje cells and NMDA receptors in molecular layer interneurons.
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Proper regulation of N-methyl-D-aspartate-type glutamate receptor (NMDA receptor) expression is responsible for excitatory synaptic functions in the mammalian brain. NMDA receptor dysfunction can cause various neuropsychiatric disorders and neurodegenerative diseases. Posttranslational protein S-palmitoylation, the covalent attachment of palmitic acid to intracellular cysteine residues via thioester bonds, occurs in the carboxyl terminus of GluN2B, which is the major regulatory NMDA receptor subunit.

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is generally known as a causative gene for a spontaneous autosomal recessive mouse mutation, Purkinje cell degeneration (). There is enough evidence that the cytosolic function of the zinc carboxypeptidase (CP) domain at the C-terminus of the Nna1 protein is associated with cell death. On the other hand, this molecule's two nuclear localization signals (NLSs) suggest some other functions exist.

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Although numerous studies have demonstrated that poor sleep increases the development of AD, direct evidence elucidating the benefits of good sleep on the AD pathogenesis is lacking. Familial Natural Short Sleepers (FNSS) are genetically wired to have lifelong reduction in nightly sleep duration without evident consequence on cognitive demise, implying that they may have better sleep quality. Here we investigated two FNSS mutations, and , on the development of tau and amyloid pathology in AD-like mouse models.

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Neurexins (NRXNs) are key presynaptic cell adhesion molecules that regulate synapse formation and function via trans-synaptic interaction with postsynaptic ligands. Here, we generate cerebellar granule cell (CGC)-specific Nrxn triple-knockout (TKO) mice for complete deletion of all NRXNs. Unexpectedly, most CGCs die in these mice, and this requirement for NRXNs for cell survival is reproduced in cultured CGCs.

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Sleep deprivation can generate inflammatory responses in the central nervous system. In turn, this inflammation increases sleep drive, leading to a rebound in sleep duration. Microglia, the innate immune cells found exclusively in the CNS, have previously been found to release inflammatory signals and exhibit altered characteristics in response to sleep deprivation.

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Protein kinase C-delta (PKCδ) has a caspase-3 recognition sequence in its structure, suggesting its involvement in apoptosis. In addition, PKCδ was recently reported to function as an anti-cancer factor. The generation of a PKCδ knockout mouse model indicated that PKCδ plays a role in B cell homeostasis.

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Prostamide/prostaglandin F synthase (PM/PGFS) is an enzyme with very narrow substrate specificity and is dedicated to the biosynthesis of prostamide F and prostaglandin F (PGF). The importance of this enzyme, relative to the aldo-keto reductase (AKR) series, in providing functional tissue prostamide F levels was determined by creating a line of PM/PGFS gene deleted mice. Deletion of the gene encoding PM/PGFS (Fam213b / Prxl2b) was accomplished by a two exon disruption.

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The endocannabinoid system modulates synaptic transmission, controls neuronal excitability, and is involved in various brain functions including learning and memory. 2-arachidonoylglycerol, a major endocannabinoid produced by diacylglycerol lipase-α (DGLα), is released from postsynaptic neurons, retrogradely activates presynaptic CB cannabinoid receptors, and induces short-term or long-term synaptic plasticity. To examine whether and how the endocannabinoid system contributes to reward-based learning of a motor sequence, we subjected male CB-knockout (KO) and DGLα-KO mice to three types of operant lever-press tasks.

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Neurons expressing neuropeptide orexins (hypocretins) in the lateral hypothalamus (LH) and serotonergic neurons in the dorsal raphe nucleus (DR) both play important roles in the regulation of sleep/wakefulness states, and show similar firing patterns across sleep/wakefulness states. Orexin neurons send excitatory projections to serotonergic neurons in the DR, which express both subtypes of orexin receptors (Mieda et al., 2011), while serotonin (5-HT) potently inhibits orexin neurons through activation of 5HT receptors (5HT1ARs).

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Calcium/calmodulin-dependent serine protein kinase (CASK)-interacting protein 1 (Caskin1) is a direct binding partner of the synaptic adaptor protein CASK. Because Caskin1 forms homo-multimers and binds not only CASK but also other neuronal proteins in vitro, it is anticipated to have neural functions; but its exact role in mammals remains unclear. Previously, we showed that the concentration of Caskin1 in the spinal dorsal horn increases under chronic pain.

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Synaptic AMPAR expression controls the strength of excitatory synaptic transmission and plasticity. An excess of synaptic AMPARs leads to epilepsy in response to seizure-inducible stimulation. The appropriate regulation of AMPARs plays a crucial role in the maintenance of the excitatory/inhibitory synaptic balance; however, the detailed mechanisms underlying epilepsy remain unclear.

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Excess energy intake causes obesity, which leads to insulin resistance and various other complications of metabolic syndrome, including diabetes, atherosclerosis, dyslipidemia, and nonalcoholic fatty liver disease. Although recent studies have depicted altered lipid metabolism as an underlying feature, the detailed mechanisms are still unclear. Here we describe a possible role in high-fat diet (HFD)-induced obesity for monoacylglycerol lipase (MGL), an enzyme that is also known to hydrolyze the endocannabinoid 2-arachidonoylglycerol in brain.

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Purkinje cell degeneration (pcd) was first identified in a spontaneous mouse mutant showing cerebellar ataxia. In addition to cerebellar Purkinje cells (PCs), retinal photoreceptors, mitral cells in the olfactory bulb, and a discrete subpopulation of thalamic neurons also degenerate in the mutant brains. The gene responsible for the pcd mutant is Nna1, also known as ATP/GTP binding protein 1 or cytosolic carboxypeptidase-like 1, which encodes a zinc carboxypeptidase protein.

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Purpose: Synthesis of keratan sulfate (KS) relies on coordinated action of multiple enzymes, including the N-acetylglucosamine-transferring enzyme, β-1,3-N-acetylglucosaminyltransferase-7 (β3GnT7). A mouse model deficient in β3GnT7 was developed to explore structural changes in KS and the extracellular matrix (ECM; i.e.

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Article Synopsis
  • Adequate sleep is crucial for overall health, and a specific mutation in the DEC2 gene has been linked to natural short sleep traits in humans.
  • Studies show that this mutation increases the expression of orexin, a neuropeptide that helps regulate arousal and wakefulness, in a mouse model.
  • The findings suggest that the DEC2 gene influences sleep duration by impacting orexin levels, notably through reduced repressor activity in the mutant version of the gene.
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Elimination of redundant synapses formed early in development and strengthening of necessary connections are crucial for shaping functional neural circuits. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs) with similar strengths. A single CF is strengthened whereas the other CFs are eliminated in each PC during postnatal development.

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Preservation of a balance between synaptic excitation and inhibition is critical for normal brain function. A number of homeostatic cellular mechanisms have been suggested to play a role in maintaining this balance, including long-term plasticity of GABAergic inhibitory synapses. Many previous studies have demonstrated a coupling of postsynaptic spiking with modification of perisomatic inhibition.

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Configuration of tripartite synapses, comprising the pre-, post-, and peri-synaptic components (axon terminal or bouton, dendritic spine, and astroglial terminal process), is a critical determinant of neurotransmitter kinetics and hence synaptic transmission. However, little is known about molecular basis for the regulation of tripartite synapse morphology. Previous studies showed that CDC42EP4, an effector protein of a cell morphogenesis regulator CDC42, is expressed exclusively in Bergmann glia in the cerebellar cortex, that it forms tight complex with the septin heterooligomer, and that it interacts indirectly with the glutamate transporter GLAST and MYH10/nonmuscle myosin ΙΙB.

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Local regulation of synaptic efficacy is thought to be important for proper networking of neurons and memory formation. Dysregulation of global translation influences long-term memory in mice, but the relevance of the regulation specific for local translation by RNA granules remains elusive. Here, we demonstrate roles of RNG105/caprin1 in long-term memory formation.

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Netrin-1 (Ntn1) emanating from the ventral midline has been thought to act as a long-range diffusible chemoattractant for commissural axons (CAs). However, CAs still grow towards the midline in the absence of the floor plate (FP), a glial structure occupying the midline. Here, using genetically loss-of-function approaches in mice, we show that Ntn1 derived from the ventricular zone (VZ), but not the FP, is crucial for CA guidance in the mouse hindbrain.

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Elimination of early-formed redundant synapses during postnatal development is essential for functional neural circuit formation. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs). A single CF is strengthened whereas the other CFs are eliminated in each PC dependent on postsynaptic activity in PC, but the underlying mechanisms are largely unknown.

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Article Synopsis
  • The voltage-gated proton channels (VSOP/Hv1), encoded by Hvcn1, play a role in ROS production in neutrophils and B lymphocytes, and could be a therapeutic target for brain ischemia due to their impact on neuronal protection.
  • Despite previous indications of a supporting role, this study shows VSOP/Hv1 has a paradoxical suppressive effect on ROS production in microglia, with results varying between Hvcn1 and wild-type (WT) mice.
  • The regulation of ROS production by VSOP/Hv1 is age-dependent, with differences observed in antioxidant gene expression and neuroprotective effects during ischemic stroke based on the age of the animals.
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