The researchers have extended the applicability of tissue clearing techniques to EM. For this, they developed an ultrastructurally-preserved tissue clearing method, ScaleSF, and LM/EM dual labeling stable in the clearing protocol. Their imaging pipeline allows for deciphering brain-wide connectivity by simultaneous interrogation of the neural circuit structure and synaptic connectivity.
With a fluorescence calcium sensor yellow cameleon, the researchers succeeded in measuring complex spike activity in over 20,000 Purkinje cells simultaneously in the mouse cerebellum. The results have shown that combining activity patterns in "olivocerebellar segments" as a whole performs distributed population coding, which represents sensory input in real-time.
The researchers identified a novel mechanism, by which amyloid β peptide (Aβ), a primary cause of Alzheimer’s disease (AD), is degraded in brain. This mechanism can be modified by diazoxide, a medication used to treat low blood sugar, implying a potential application of this mechanism to prevention and treatment of AD.
The researchers established a new method for PET imaging of the expression, chemogenetic manipulation, and intermolecular interaction of reporter proteins in the neural circuit of living animals. This technique may facilitate a broad spectrum of PET analyses of a mammalian brain circuit at molecular levels that were not previously applicable for technical reasons.
In the cortex of a marmoset model of autism exposed to valproic acid in utero, genes associated with neurons and oligodendrocytes were down-regulated, and genes associated with microglia and astrocytes were up-regulated, as in human autism. However, the current major rodent models could only reproduce human autism in at most two of the four cell types of the brain. This confirms the prediction that primate autism models reproduce human autism better than rodent models by an objective method of transcriptome comparison.
The researchers generated a new Alzheimer’s disease (AD) mouse model that more faithfully recapitulate pathology of AD patients compared to the previous ones. This new third-generation mouse model will help accelerate the elucidation of the disease mechanisms and development of disease-modifying therapies to treat AD.
By recording neuronal activity from a Japanese monkey model of Parkinson’s disease, the researchers have elucidated the neural mechanisms underlying parkinsonian symptoms. Disturbance of information flow through the “direct pathway” in the basal ganglia is responsible for parkinsonian symptoms, and its restoration has beneficial effects on the symptoms.
The researchers demonstrated that auditory gamma oscillation is globally distributed among the temporal, parietal, and frontal cortices by using intracranial recordings implanted for the diagnostic purpose of the intractable epilepsy. Elucidation of the mechanism of gamma oscillation, which is decreased in psychiatric disorders such as schizophrenia, is expected to be useful for the development of future diagnosis and treatment.
Comprehensive expression analysis of genes associated with developmental disorders and psychiatric disorders in the common marmoset brain revealed that these genes are expressed in a specific brain region. Also, by comparing the expression patterns of the mouse and human brain, it was clarified that there are many common expression patterns between marmosets and humans.
The researchers performed comprehensive DNA methylation analyses of neurons from patients with bipolar disorder, and found that many genes were hypomethylated in patients, while genes important for neuronal function were hypermethylated. Differentially methylated regions in neurons were significantly enriched in genomic regions suggested by a genome-wide association study of bipolar disorder, indicating an association with genetic factors.
The researchers developed a fast and wide field-of-view two-photon microscopy with practically no optical aberrations. Combining high-performance large lenses and devices and a fast laser scanning mirror enables the recording of over 16,000 neurons in awake mice. Functional network analysis with single-cell resolution reveals the small-world behavior of the cortex.
This work develops an unsupervised learning scheme that extracts the most informative components for predicting future inputs, which is called PredPCA (predictive principal component analysis). We demonstrate that PredPCA can extract hidden features important for predicting previously unseen videos. This scheme is potentially useful for automated driving and medical diagnosis.
The researchers demonstrated that perampanel, an antiepileptic drug, inhibited the activity-dependent neuronal uptake of α-synuclein preformed fibrils via macropinocytosis and the subsequent development of α-synuclein inclusions in Parkinson’s disease models. Targeting neuronal activity with perampanel could represent a new therapeutic strategy for Parkinson’s disease.
In this article, the researchers established a species-wide method for deriving transgene-free iPSCs, and discovered primary colony-forming cells showed a neural stem cell-like profile, named induced neural stem cell-like cells (iNSLCs).
The researchers developed a new inhibitory neuron-specific promoter, GAD65 promoter. Intravenous infusion of blood-brain barrier-penetrating AAV-PHP.B expressing an enhanced green fluorescent protein under the control of the mGAD65 promoter transduced the whole brain in an inhibitory neuron-specific manner.
The researchers utilized the diffusion MRI and neural tracer data of marmoset brains collected by the Brain/MINDS project to optimize the parameters of the algorithms for estimating whole-brain neural connections (connectome). The optimization allowed tracking of long-range fibers and raised an issue of parameter selection in connectomic studies.
Patients with 22q11.2 deletion syndrome (22q11.2DS) suffer from the onset risk for neuropsychiatric disorders over their lifetime. In this study, the researchers revealed “PRKR-Like Endoplasmic Reticulum Kinase-dependent vulnerabilities in dopaminergic neurons” as one of the molecular pathologies in brains of 22q11.2DS.
The researchers demonstrated that mimicking a de novo mutation of the schizophrenia-risk gene SETD1A in mice induced various abnormal behaviors relevant to schizophrenia. Setd1a in postsynaptic neurons positively regulates excitatory synaptic transmission and structure in the medial prefrontal cortex through histone modification and regulating the expression of diverse synaptic genes.
Direct and indirect pathway medium-sized spiny neurons (dMSNs and iMSNs) in the neostriatum were selectively labeled with green and red fluorescent proteins by an AAV vector. Both pathways formed two axonal arborizations in the globus pallidus external segment, and dMSN axons converged in the center of iMSN projection fields.
The researchers developed a simplified method for the production of AAV vectors, which drastically shortens the purification time from 1.5 days to 2 – 4 h. Systemic infusion of AAV-PHP.eB prepared using this method transduced whole brain. Transduction efficacy is comparable to the conventional method.
A machine learning classifier using neuroimaging data in schizophrenia, autism, and healthy controls classifies people with ultra-high risk and first episode psychosis into schizophrenia or healthy controls, but not autism.
Disruption of the FUS-SFPQ interaction was observed in a wide-range of FTLD spectrum diseases. Imbalanced ratio of tau isoforms regulated by FUS/SFPQ was observed in a wide-range of FTLD spectrum diseases as well. These results were not observed in Alzheimer disease, or Pick disease, indicating that impaired interactions of FUS/SFPQ is a common pathogenesis in FTLD spectrum diseases.
In this study, we generated transgenic fetal marmosets that express ARHGAP11B, a human specific gene. In the fetus brain of the transgenic marmoset, the number of bRG cells, a type of neural progenitor cell, were increased and led to an enlarged neocortex with a folded brain surface. Our study demonstrates that ARHGAP11B drives the changes in marmoset development which reflects those in the evolution of human neocortex.
The researchers revealed that increased DNA methylation in the serotonin transporter gene in schizophrenia and bipolar patients. The methylation level is inversely correlated with volume of the amygdala in patients. This work is expected to lead to a better understanding of the pathophysiology of schizophrenia and bipolar disorder.
The research group found that the upstream insular cortical silencing is converted to the downstream ventrolateral striatal activation in behaving animals. Parvalbumin-expressing interneurons in the ventrolateral striatum mediate this conversion through feedforward disinhibition.
Through investigation of the behaviors/fates of fluorescent proteins inside lysosomes, we developed a signa-retaining autophagy indicator (SRAI). We localized SRAI into mitochondria (mito-SRAI) to quantitatively measure mitophagy. We apply the new tool in a high-throughput in vitro screen for chemical inducers of mitophagy and in a mouse model of Parkinsons disease.
The researchers have successfully designed a novel three-dimensional staining and imaging technique, CUBIC-HistoVIsion, based on the physicochemical properties of biological tissues as an electrolyte gel. They demonstrated the staining of whole mouse brains, human brains, and whole marmoset bodies. This technique thus allows detailed analysis of brain circuits with cellular resolution.
Production and deposition of amyloid β peptide (Aβ) are the initial steps of pathogenesis of Alzheimer disease (AD). This study successfully identified CIB1 as a negative regulator of Aβ production by CRISPR/Cas9 screening. Furthermore, single-cell RNA-seq revealed the decreased CIB1 mRNA in early stage of AD patients, indicating that CIB1 is involved in AD pathogenesis.
This study revealed the association between Parkinson’s disease (PD) and the prosaposin saposin D domain (PSAP-D). iPS cells from patients with PSAP-D mutation showed an accumulation of alpha-synuclein. Mouse with PSAP-D mutation showed dopaminergic neurodegeneration. Furthermore, two variants in the intronic regions of the PSAP-D in sporadic PD had significantly higher allele frequencies.
This study shows that POGZ, one of the most recurrently de novo mutated gene products in patients with ASD, regulates neuronal development and that ASD-related mutations on POGZ impair the POGZ function. These results provide insight into how de novo mutations on POGZ lead to impaired mature cortical network function.
Patients with schizophrenia showed a selective impairment in deviance detection component of the mismatch negativity compared to healthy comparison subjects in the current study. Future investigation of the neural mechanisms underlying deviance detection will be important for clarifying the pathophysiology of schizophrenia and developing new treatments.
Research group led by professor Takuya Takahashi at Yokohama City University developed a positron emission tomography (PET) tracer for AMPA receptor, a most important synaptic protein, which enables us to visualize AMPA receptors in living human brain. This can lead to the elucidation of neuropsychiatric disorders, providing novel diagnostics and therapeutics.
We created prodromal Parkinson’s disease (PD) mice model exhibiting hyposmia and REM sleep behavior disorders (RBD) as well as α-synuclein deposition and mild dopaminergic cell loss. This mice model can contribute to the development of disease-modifying therapies and preventive treatments in the prodromal stage of PD.
Mega-analyses indicated similar white matter microstructural abnormalities between schizophrenia and bipolar disorder in the limbic system, while autism spectrum disorder also shared abnormalities in the corpus callosum. Major depression showed a relative lack of white matter microstructural defects. Schizophrenia was unique in having defects in discrete neocortical tracks. This study was published in 『Molecular Psychiatry』
We improved a method of optogenetic cortical stimulation and induced overt forelimb movements in the common marmoset, a New World monkey. Our results open doors for noninvasive interrogation of motor circuits in behaving nonhuman primates to address which brain area drives hand/arm movements after learning or brain injury.
Sense of agency (SoA) refers to the experience that one's own actions caused an external event. Here, the authors present a model of SoA in terms of optimal Bayesian cue integration taking into account reliability of action and outcome sensory signals and judging if the action caused the outcome.
We confirmed, for the first time, that Lewy bodies contained amyloid fibrils using autopsied brains of Parkinson's disease patients. Collaborative research with the large-scale synchrotron radiation facility, SPring-8, enabled ultrastructural analysis of aggregates in brain sections. These new findings are expected to be applied to the development of diagnostic and therapeutic approaches for Parkinson's disease.
A new protein involved in Alzheimer’s disease (AD) has been identified by researchers at the RIKEN Center for Brain Science (CBS). CAPON may facilitate the connection between the two most well-known AD culprits, amyloid plaques and tau pathology, whose interactions cause brain cell death and symptoms of dementia. This latest finding from the Takaomi Saido group at RIKEN CBS uses a novel mouse model of AD.
The study was published in Nature Communications on June 3.
We here developed a multicolor GECI suite, "XCaMP", which enables to image high-frequency firing patterns, non-invasively measure hippocampal CA1 dynamics, and simultaneously record pre- and postsynaptic firing, or co-image neuronal activities in 4 distinct celltypes. XCaMPs will be useful for elucidating complex brain circuit dynamics in health and neuropsychiatric diseases.
Recording the activity of neurons over large brain regions requires expanding the field of view of the optics without losing on spatial and temporal resolution. Here, this team reports a micro-opto-mechanical device that enables two-photon imaging across distant cortical areas around 6 mm apart in the mouse.
It remains unclear how direct and indirect pathways of the basal ganglia signal functional information for a goal-directed adaptive behavior. Combining electrophysiology and optogenetics in behaving rats, we found the direct pathway neurons reselect the same action after reward outcome, whereas indirect pathway neurons switch to the other action after no-reward outcome.
The research team led by Hideyuki Okano and Junichi Ushiba (Keio University) demonstrate calcium imaging from neuronal populations using a miniature fluorescence microscope in naturally behaving non-human primates (NHPs), common marmosets. This technique marks an advance beyond methods using fixed head positioning, which limits the study of complex, self-determined behaviors such as social interactions or fear/anxiety.
MARCKS Phosphorylation at Ser46 reflects neurite degeneration and is a candidate marker for presymptomatic and preaggretaion pathology of Alzheimer’s disease. Here, we demonstrate the similar change in Parkinson’s disease and Dementia with Lewy body prior to alpha-synuclein aggregation, and suggest an ultra-early stage pathology shared by different groups of neurodegenerative diseases.
The ventral tegmental area (VTA) and substantia nigra (SN) are involved in dopaminergic brain functions. Given that there are no VTA or SN anatomical MRI templates for Asian people, we created these templates and showed suitability for Asian brains using anatomical and resting state functional MRI data.
The research team led by Profs. Norio Ozaki (Nagoya University) and Hideyuki Okano (Keio University) revealed that a rare RELN variant, initially identified in a schizophrenic patient, causes a loss of directional stability during neuronal migration using human iPSCs generated from the patient. These findings are expected to contribute to understanding the molecular pathophysiology and/or developing drugs for mental disorders.
Arioka Y, Shishido E, Kubo H, Kushima I, Yoshimi A, Kimura H, Ishizuka K, Aleksic B, Maeda T, Ishikawa M, Kuzumaki N, Okano H, Mori D, Ozaki N: Single-cell trajectory analysis of human homogenous neurons carrying a rare RELN variant. Transl Psychiatry 8 (1):129, 2018
Intellectual deterioration may play a key role in work disturbances in patients with schizophrenia. The study demonstrated probabilistic models to estimate work status in patients with schizophrenia based on relevant factors including intellectual deterioration. Feedback on work status would support social rehabilitation in patients with schizophrenia.
The present study demonstrated that tau pathology in orbitofrontal cortex (OFC) may provoke focal neurotoxicity in OFC and the following disruption of the OFC-uncinate fasciculus network, leading to the emergence and progression of apathy in Alzheimer’s disease. The current data also raise the possibility that emerging antitau drugs would be efficacious for suppressing apathy.
By combining an 8K ultra-high-definition camera with spinning-disk one-photon confocal microscopy, we succeeded in imaging of activity of presynaptic axonal boutons of neurons projecting to the motor cortex in a behaving mouse. We detected axonal boutons with highly correlated activity over the 1 mm2 field.
This article was published in "Biochemical and Biophysical Research Communications, Volume 500, Issue 2".
Brain damage such as stroke is a devastating neurological condition, which may severely compromise patient quality of life. No effective medication-mediated intervention to accelerate rehabilitation has been established. We found that a small compound, edonerpic-maleate, facilitated experience-driven synaptic glutamate AMPAreceptor delivery and resulted in the acceleration of motor function recovery after brain damage in a training-dependent manner.
Bioluminescence is a natural light source based on luciferase catalysis of its substrate luciferin. We performed directed evolution on firefly luciferase using a red-shifted and highly deliverable luciferin analog to establish AkaBLI, an all-engineered bioluminescence in vivo imaging system.
This research result was published in "Science 23 Feb 2018".
Mutations in the progranulin (PGRN) gene cause a tau pathology-negative and TDP43 pathology-positive form of frontotemporal lobar degeneration (FTLD-TDP). We generated a knock-in mouse harboring the R504X mutation (PGRN-KI).
This research result was published on Nature Communications, 30 January 2018.
Subcortical regions have a pivotal role in cognitive, affective, and social functions in humans, and the structural and functional abnormalities of the regions have been associated with various psychiatric disorders.
This research result was published on Scientific Reports, volume 8, 19 January 2018.
We examined the neural basis of persuasion-induced changes in attitude toward and away from norms using fMRI. We measured brain activity while human participants were exposed to persuasive messages directed toward specific norms.
This research result was published on Scientific Reports volume 7, Article number: 16295, 24 November 2017.
Researchers at the RIKEN Brain Science Institute and collaborative project have discovered that the benefits of stimulating the brain with direct current come from its effects on astrocytes — not neurons — in the mouse brain. Published in Nature Communications, the work shows that applying direct current to the head releases synchronized waves of calcium from astrocytes that can reduce depressive symptoms and lead to a general increase in neural plasticity — the ability of neuronal connections to change when we try to learn or form memories.
In cerebellar Purkinje cells (PCs), dendritic territories by climbing and parallel fiber (PF) innervations are segregated. Here, we show that the segregation of territories occurs as a result of elimination of PF synapses from the proximal dendrites, and that PF synapse elimination is controlled by the type 1 metabotropic glutamate receptor to protein kinase Cg signaling pathway in PCs.
Press Release Mirror Neurons in a New World Monkey, Common Marmoset
The research team including researchers from NCNP and RIKEN BSI found neurons in the ventrolateral frontal cortex with characteristic “mirror” properties quite similar to those in macaques. This finding suggests that mirror neurons occur in a common ancestor of New and Old World monkeys and its common properties are preserved during the course of primate evolution.
Researchers at the RIKEN Brain Science Institute in Japan have developed a new system for imaging the activity of individual neurons in the marmoset brain. Published in Cell Reports, the study shows how amplifying genetically encoded fluorescent signals with TET-inducible gene expression allows hundreds of individual neurons in the primate brain to be imaged simultaneously over a period of several months.
It remains unclear how readiness for Ca2+ -dependent exocytosis depends on varying degrees of SNARE complex assembly. We demonstrated the SNARE assembly using ﬂuorescence lifetime imaging (FLIM) of Forster resonance energy transfer (FRET) between three pairs of neuronal SNAREs in presynaptic boutons and pancreatic beta cells in the islets of Langerhans.
The research team including researchers from RIKEN BSI and NIPS established a new method to visualize dendritic spines in the living marmoset brain. The method that utilizes two-photon microscopy in combination with virus vectors to enhance the expression of fluorescent signals makes it possible to study neural circuits in primate brains.
Press Release Real x-ray vision: see-through brains ready for study
Researchers at the RIKEN Brain Science Institute in Japan have developed a new technique for creating transparent tissue that can be used to illuminate 3D brain anatomy at very high resolutions. Published in Nature Neuroscience, the work showcases the new technology and its practical importance in clinical science by showing how it has given new insights into Alzheimer’s disease plaques.
The research team led by Prof. Okazawa (Tokyo Medical and Dental University) developed a new technique for observation
of autophagy in the brain in vivo, and revealed unexpected roles of autophagy in Alzheimer's disease
including the increase of intracellular Amyloid beta by starvation and circadian rhythm of neuronal autophagy activity.
Brains, Genes, and Primates
Brain/MINDS: brain-mapping project in Japan- Philosophical Transactions B
Hideyuki Okano, Atsushi Miyawaki, Kiyoto Kasai