Imaging Prior Information in the Brain

In making sense of the visual world, the brain\u27s processing is driven by two factors: the physical information provided by the eyes (“bottom-up” data) and the expectancies driven by past experience (“top-down” influences). We use degraded stimuli to tease apart the effects of bottom-up and top-down processes because they are easier to recognize with prior knowledge of undegraded images. Using machine learning algorithms, we quantify the amount of information that brain regions contain about stimuli as the subject learns the coherent images. Our results show that several distinct regions, including high-level visual areas and the retinotopic cortex, contain more information about degraded stimuli with prior knowledge. Critically, these regions are separate from those that exhibit classical priming, indicating that top-down influences are more than feature-based attention. Together, our results show how the neural processing of complex imagery is rapidly influenced by fleeting experiences

Functional imaging of visual cortical layers and subplate in awake mice with optimized three-photon microscopy

Two-photon microscopy is used to image neuronal activity, but has severe limitations for studying deeper cortical layers. Here, we developed a custom three-photon microscope optimized to image a vertical column of the cerebral cortex > 1 mm in depth in awake mice with low (<20 mW) average laser power. Our measurements of physiological responses and tissue-damage thresholds define pulse parameters and safety limits for damage-free three-photon imaging. We image functional visual responses of neurons expressing GCaMP6s across all layers of the primary visual cortex (V1) and in the subplate. These recordings reveal diverse visual selectivity in deep layers: layer 5 neurons are more broadly tuned to visual stimuli, whereas mean orientation selectivity of layer 6 neurons is slightly sharper, compared to neurons in other layers. Subplate neurons, located in the white matter below cortical layer 6 and characterized here for the first time, show low visual responsivity and broad orientation selectivity.National Institutes of Health (U.S.) (grant EY007023)National Institutes of Health (U.S.) (grant NS090473)National Institutes of Health (U.S.) (grant 4-P41-EB015871)National Science Foundation (U.S.) (grant EF1451125)Picower Institute for Learning and Memory (Engineering Collaboration Grant)Massachusetts Life Sciences Initiativ

High-performance pipeline for MutMap and QTL-seq

[Summary] Bulked segregant analysis implemented in MutMap and QTL-seq is a powerful and efficient method to identify loci contributing to important phenotypic traits. However, the previous pipelines were not user-friendly to install and run. Here, we describe new pipelines for MutMap and QTL-seq. These updated pipelines are approximately 5–8 times faster than the previous pipeline, are easier for novice users to use, and can be easily installed through bioconda with all dependencies. [Availability] The new pipelines of MutMap and QTL-seq are written in Python and can be installed via bioconda. The source code and manuals are available online (MutMap: https://github.com/YuSugihara/MutMap, QTL-seq: https://github.com/YuSugihara/QTL-seq)

Clinical features and treatment outcome of very elderly patients over 80 years old with multiple myeloma:comparison with patients in different age groups in the era of novel agents

We retrospectively analyzed the outcomes of 175 consecutive patients admitted to our hospital between April 2004 and June 2014, and identified 42 (24%), 80 (46%), and 53 (30%) patients 80, 66-79, and 65 years old, respectively. The median progression-free survival (PFS) and overall survival (OS) of the 80, 66-79, and 65 years old groups were 19.1, 26.3, and 54.3 months, and 31.9, 54.8, and 83.8 months, respectively. Patients 80 but not 79 years old with ECOG performance score (PS) 3 and/or Charlson comorbidity index (CCI) 5 showed significantly shorter survival. ECOG PS and CCI predicted the treatment outcome of patients 80 but did not predict 79 years old.</p

A Case of Isolated Septal Myocardial Infarction: Myocardial Perfusion-Metabolism Mismatch as a Tool for Diagnosis

Isolated septal myocardial infarction is an uncommon condition with diagnostic difficulty due to small infarction size and anatomical variations. We report a case of isolated septal myocardial infarction, in which the diagnosis was confirmed not by electrocardiographic, echocardiographic, or angiographic findings, but by nuclear imaging. A 46-year-old man with chest discomfort exhibited ST-segment elevations in leads V1 and V2, and borderline abnormalities of the septal wall motion on echocardiography. Emergency coronary angiography demonstrated delayed flow in the second septal branch of the left anterior descending coronary artery. Intravascular ultrasound showed plaque in the proximal portion of the septal branch without evidence of plaque rupture. No balloon angioplasty or stent implantation was required because the flow delay in the septal branch disappeared after the intravascular ultrasound procedure. Myocardial perfusion-metabolism mismatch, as assessed by resting thallium-201 and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid, was seen in the mid-septal region

Two-dimensional heavy fermion in a monoatomic-layer Kondo lattice YbCu2

Nakamura T., Sugihara H., Chen Y., et al. Two-dimensional heavy fermion in a monoatomic-layer Kondo lattice YbCu2. Nature Communications 14, 7850 (2023); https://doi.org/10.1038/s41467-023-43662-9.The Kondo effect between localized f-electrons and conductive carriers leads to exotic physical phenomena. Among them, heavy-fermion (HF) systems, in which massive effective carriers appear due to the Kondo effect, have fascinated many researchers. Dimensionality is also an important characteristic of the HF system, especially because it is strongly related to quantum criticality. However, the realization of the perfect two-dimensional (2D) HF materials is still a challenging topic. Here, we report the surface electronic structure of the monoatomic-layer Kondo lattice YbCu2 on a Cu(111) surface observed by synchrotron-based angle-resolved photoemission spectroscopy. The 2D conducting band and the Yb 4f state, located very close to the Fermi level, are observed. These bands are hybridized at low-temperature, forming the 2D HF state, with an evaluated coherence temperature of about 30 K. The effective mass of the 2D state is enhanced by a factor of 100 by the development of the HF state. Furthermore, clear evidence of the hybridization gap formation in the temperature dependence of the Kondo-resonance peak has been observed below the coherence temperature. Our study provides a new candidate as an ideal 2D HF material for understanding the Kondo effect at low dimensions

TRITIUM, HYDROGEN AND OXYGEN ISOTOPE COMPOSITIONS IN MONTHLY PRECIPITATION SAMPLES COLLECTED AT TOKI, JAPAN

Monthly precipitation samples have been collected at Toki, Japan, from November 2013 to March 2017. In this report, selected data were analysed to identify the regional hydrogen and oxygen isotope compositions. Tritium (3H) concentration in the precipitation ranged from 0.10 to 0.61 Bq L−1 and higher 3H concentrations were observed in spring rather than in other seasons. This range was similar to values reported in Chiba City, Japan. 3H concentration and the ratio d-excess, and δD values were roughly clustered according to each separate season. These regional hydrogen and oxygen isotope compositions will be used for environmental assessments of effects of the deuterium plasma experiments of the large fusion test device

Case report: Recurring and treatment-resistant depression in acquired hepatocerebral degeneration due to a congenital portosystemic shunt

IntroductionAcquired hepatocerebral degeneration (AHD) is a neurological condition associated with cerebral manganese (Mn) accumulation caused by portosystemic shunts (PSS), usually because of advanced liver disease. AHD is diagnosed by the identification of T1-weighted brain magnetic resonance imaging (MRI) hyperintensities coupled with the presence of PSS and neurological symptoms. Clinical presentations primarily involve motor dysfunction and cognitive impairment. As a result of the frequently concurrent hepatic encephalopathy, the psychiatric symptoms of AHD alone remain unclear. This report is the first documentation of unique psychiatric symptoms of AHD due to a congenital PSS (CPSS) and suggests the efficacy of shunt embolization in achieving sustained remission of psychiatric symptoms in such cases.MethodsA 57-year-old Japanese woman presented with recurrent severe depression, pain, and somatosensory hallucinations, along with fluctuating motor dysfunction, including parkinsonism, and cognitive impairments. Psychiatric interventions, including antidepressants, antipsychotics or electroconvulsive therapy, had limited efficacy or did not prevent relapse.ResultsT1-weighted MRI showed bilateral hyperintensity in the globus pallidus. No history of Mn exposure or metabolic abnormalities, including copper, was identified. Furthermore, no evidence of liver dysfunction or hyperammonemia was found. Eventually, a gastrorenal shunt was observed on contrast-enhanced abdominal computed tomography. The diagnosis of AHD due to CPSS was made based on the clinical manifestations and abnormal imaging findings. Shunt embolization was performed, which prevented the relapse of psychiatric symptoms and substantially reduced the T1-weighted MRI hyperintensities.ConclusionsThis case highlights the potential involvement of AHD in adult-onset psychiatric symptoms, even in the absence of liver disease. Furthermore, this case underscores the efficacy of shunt embolization in treating the psychiatric symptoms of AHD due to CPSS

Adaptive Filtering Enhances Information Transmission in Visual Cortex

Sensory neuroscience seeks to understand how the brain encodes natural environments. However, neural coding has largely been studied using simplified stimuli. In order to assess whether the brain's coding strategy depend on the stimulus ensemble, we apply a new information-theoretic method that allows unbiased calculation of neural filters (receptive fields) from responses to natural scenes or other complex signals with strong multipoint correlations. In the cat primary visual cortex we compare responses to natural inputs with those to noise inputs matched for luminance and contrast. We find that neural filters adaptively change with the input ensemble so as to increase the information carried by the neural response about the filtered stimulus. Adaptation affects the spatial frequency composition of the filter, enhancing sensitivity to under-represented frequencies in agreement with optimal encoding arguments. Adaptation occurs over 40 s to many minutes, longer than most previously reported forms of adaptation.Comment: 20 pages, 11 figures, includes supplementary informatio

Osteoblast-derived vesicles induce a switch from bone-formation to bone-resorption in vivo

Bone metabolism is regulated by the cooperative activity between bone-forming osteoblasts and bone-resorbing osteoclasts. However, the mechanisms mediating the switch between the osteoblastic and osteoclastic phases have not been fully elucidated. Here, we identify a specific subset of mature osteoblast-derived extracellular vesicles that inhibit bone formation and enhance osteoclastogenesis. Intravital imaging reveals that mature osteoblasts secrete and capture extracellular vesicles, referred to as small osteoblast vesicles (SOVs). Co-culture experiments demonstrate that SOVs suppress osteoblast differentiation and enhance the expression of receptor activator of NF-κB ligand, thereby inducing osteoclast differentiation. We also elucidate that the SOV-enriched microRNA miR-143 inhibits Runt-related transcription factor 2, a master regulator of osteoblastogenesis, by targeting the mRNA expression of its dimerization partner, core-binding factor β. In summary, we identify SOVs as a mode of cell-to-cell communication, controlling the dynamic transition from bone-forming to bone-resorbing phases in vivo.Uenaka M., Yamashita E., Kikuta J., et al. Osteoblast-derived vesicles induce a switch from bone-formation to bone-resorption in vivo. Nature Communications 13, 1066 (2022); https://doi.org/10.1038/s41467-022-28673-2