Effects of L-glutamate on cyclic AMP levels in slices from different areas of rat cerebral cortex with a chronic iron-induced focus.

The effect of L-glutamate of cyclic AMP levels in different areas of rat cerebral cortex was examined during the development of an iron-induced focus in the left sensorimotor cortex. The addition of L-glutamate resulted in increased cyclic AMP levels in slices from the quarter of cortex with the iron-induced focus. The levels lowered in slices from the quarter of cortex most remote from the focus. Thus L-glutamate showed stimulatory and inhibitory effects on the accumulation of cyclic AMP.</p

Factors Influencing Breast Density in Japanese Women Aged 40-49 in Breast Cancer Screening Mammography

A relatively large number of women in their 40s with high-density breasts, in which it can be difficult to detect lesions, are encountered in mammography cancer screenings in Japan. Here, we retrospectively investigated factors related to breast density. Two hundred women (40-49 years old) were examined at the screening center in our hospital. Multivariate analysis showed that factors such as small abdominal circumference, high HDL cholesterol, and no history of childbirth were related to high breast density in women in their 40s undergoing mammography. Other non-mammographic screening methods should be considered in women with abdominal circumferences ＜76cm, HDL-C >53mg/dl, and no history of childbirth, as there is a strong possibility of these women having high-density breasts that can make lesion detection difficult

Multiscale chemogenetic dissection of fronto-temporal top-down regulation for object memory in primates

見た物の記憶を保持する霊長類の脳ネットワークとメカニズムを解明 --認知症の記憶障害治療への応用に期待-- .京都大学プレスリリース. 2024-07-12.Visual object memory is a fundamental element of various cognitive abilities, and the underlying neural mechanisms have been extensively examined especially in the anterior temporal cortex of primates. However, both macroscopic large-scale functional network in which this region is embedded and microscopic neuron-level dynamics of top-down regulation it receives for object memory remains elusive. Here, we identified the orbitofrontal node as a critical partner of the anterior temporal node for object memory by combining whole-brain functional imaging during rest and a short-term object memory task in male macaques. Focal chemogenetic silencing of the identified orbitofrontal node downregulated both the local orbitofrontal and remote anterior temporal nodes during the task, in association with deteriorated mnemonic, but not perceptual, performance. Furthermore, imaging-guided neuronal recordings in the same monkeys during the same task causally revealed that orbitofrontal top-down modulation enhanced stimulus-selective mnemonic signal in individual anterior temporal neurons while leaving bottom-up perceptual signal unchanged. Furthermore, similar activity difference was also observed between correct and mnemonic error trials before silencing, suggesting its behavioral relevance. These multifaceted but convergent results provide a multiscale causal understanding of dynamic top-down regulation of the anterior temporal cortex along the ventral fronto-temporal network underpinning short-term object memory in primates

Chemogenetic sensory fMRI reveals behaviorally relevant bidirectional changes in primate somatosensory network

手と足の感覚は、実は脳の中でつながっていた --脳障害による活動変化の広がりを見ることで常識を覆す発見、脳機能・疾患機序の理解へ前進--. 京都大学プレスリリース. 2021-10-21.Concurrent genetic neuromodulation and functional magnetic resonance imaging (fMRI) in primates has provided a valuable opportunity to assess the modified brain-wide operation in the resting state. However, its application to link the network operation with behavior still remains challenging. Here, we combined chemogenetic silencing of the primary somatosensory cortex (SI) with tactile fMRI and related behaviors in macaques. Focal chemogenetic silencing of functionally identified SI hand region impaired grasping behavior. The same silencing also attenuated hand stimulation-evoked fMRI signal at both the local silencing site and the anatomically and/or functionally connected downstream grasping network, suggesting altered network operation underlying the induced behavioral impairment. Furthermore, the hand region silencing unexpectedly disinhibited foot representation with accompanying behavioral hypersensitization. These results demonstrate that focal chemogenetic silencing with sensory fMRI in macaques unveils bidirectional network changes to generate multifaceted behavioral impairments, thereby opening a pivotal window toward elucidating the causal network operation underpinning higher brain functions in primates

Association of cognitive performance with interleukin-6 receptor Asp358Ala polymorphism in healthy adults

Wechsler adult intelligence scale-revised was performed in 576 healthy adults to examine whether a functional polymorphism (Asp358Ala) of the IL-6 receptor (IL-6R) gene is associated with cognitive performance. Verbal intelligence quotient in Asp homozygotes was significantly higher compared to Ala carriers (P = 0.005). Compared to Ala carriers, Asp homozygotes performed better in the verbal subtests requiring long-term memory stores. Elevated IL-6 and soluble IL-6R levels in Ala carriers may have negative impact on acquiring verbal cognitive ability requiring long-term memory.ArticleJOURNAL OF NEURAL TRANSMISSION. 119(3):313-318 (2012)journal articl

Production and nutrient cycling in Antarctic lakes deciphered from stable isotope measurements

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月27日（火） 国立極地研究所 ３階ラウン

Nutrient cycling in the lakes near the Syowa Station

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Microfluidic Chemotaxis Platform for Differentiating the Roles of Soluble and Bound Amyloid-β on Microglial Accumulation

Progressive microglial accumulation at amyloid-β (Aβ) plaques is a well-established signature of the pathology of Alzheimer's disease, but how and why microglia accumulate in the vicinity of Aβ plaques is unknown. To understand the distinct roles of Aβ on microglial accumulation, we quantified microglial responses to week-long lasting gradients of soluble Aβ and patterns of surface-bound Aβ in microfluidic chemotaxis platforms. We found that human microglia chemotaxis in gradients of soluble Aβ42 was most effective at two distinct concentrations of 23 pg.mL−1 and 23 ng.mL−1 Aβ42 in monomers and oligomers. We uncovered that while the chemotaxis at higher Aβ concentrations was exclusively due to Aβ gradients, chemotaxis at lower concentrations was enhanced by Aβ-induced microglial production of MCP-1. Microglial migration was inhibited by surface-bound Aβ42 in oligomers and fibrils above 45 pg.mm−2. Better understanding of microglial migration can provide insights into the pathophysiology of senile plaques in AD

Association of interleukin-1 beta genetic polymorphisms with cognitive performance in elderly females without dementia

Interleukin-1 beta (IL-1 beta) is considered to have a role in age-related cognitive decline. A recent study has shown that a promoter polymorphism of the IL-1 beta gene (rs16944) is associated with cognitive performance in elderly males without dementia. In this study, we examined whether polymorphisms of the IL-1 beta gene also influence cognitive functions in elderly females. Cognitive functions were assessed by the Wechsler adult intelligence scale-revised (WAIS-R) in 99 elderly (>= 60 years) females without dementia. We selected five tagging polymorphisms from the IL-1 beta gene and examined the associations with the WAIS-R scores. Significant associations were found between verbal intelligence quotient (IQ) and the genotypes of rs1143634 and rs1143633 (P = 0.0037 and P = 0.010, respectively). No significant associations of rs16944 genotype were found with verbal or performance IQ. However, individuals homozygous for the G allele of rs16944 achieved higher scores in digit span compared with their counterpart, which is consistent with the previous findings in males. These results suggest that IL-1 beta gene variation may have a role in cognitive functions in aging females as well as males. Journal of Human Genetics (2011) 56, 613-616; doi:10.1038/jhg.2011.56; published online 26 May 2011ArticleJOURNAL OF HUMAN GENETICS. 56(8):613-616 (2011)journal articl