Biology subjects

Tsukada, H.

Publications and source records attributed to Tsukada, H..

3 recordsLinked to original sources

bioRxiv2022

Multi-modal brain magnetic resonance imaging database covering marmosets with a wide age range

Magnetic resonance imaging (MRI) is a noninvasive neuroimaging method beneficial for the identification of normal developmental and aging processes and data sharing. Marmosets have a relatively shorter life expectancy (approximately 10 years) than other primates, including, humans because they grow and age faster. Hence, the common marmoset model is effective in aging research. The current study investigated the aging process of the marmoset brain and provided an open MRI database on marmosets with a wide age range. The Brain/MINDS Marmoset Brain MRI Dataset contains brain MRI information on 216 marmosets aged between 1 and 10 years. During its release date, it is the largest public dataset worldwide. Further, it comprises multi contrast MRI images. In addition, 91 of 216 animals have corresponding ex vivo high-resolution MRI datasets. Our MRI database, which is available at the Brain/MINDS Data portal might help understand the effects of different factors, such as age, sex, body size, and fixation, on the brain. Moreover, it can contribute to and accelerate brain science studies worldwide.

neuroscience↗

bioRxiv2022

The Brain/MINDS Marmoset Connectivity Atlas: Exploring bidirectional tracing and tractography in the same stereotaxic space

We report on the implementation and features of the Brain/MINDS Marmoset Connectivity Atlas, BMCA, a new resource that provides access to anterograde neuronal tracer data in the prefrontal cortex of a marmoset brain. Neuronal tracers combined with fluorescence microscopy are a key technology for the systematic mapping of structural brain connectivity. We selected the prefrontal cortex for mapping due to its important role in higher brain functions. This work introduces the BMCA standard image preprocessing pipeline and tools for exploring and reviewing the data. We developed the BMCA-Explorer, which is an online image viewer designed for data exploration. Unlike other existing image explorers, it visualizes the data of different individuals in a common reference space at an unprecedented high resolution, facilitating comparative studies. To foster the integration with other marmoset brain image databases and cross-species comparisons, we added fiber tractography data from diffusion MRI, retrograde neural tracer data from the Marmoset Brain Connectivity Atlas project, and tools to map image data between marmoset and the human brain image space. This version of BMCA allows direct comparison between the results of 52 anterograde and 164 retrograde tracer injections in the cortex of the marmoset.

neuroscience↗

bioRxiv2021

Oxidized alkyl phospholipids stimulate sodium transport in proximal tubules via PPAR-dependent pathway

The pleiotropic effects of oxidized phospholipids (oxPLs) have been identified. 1-O-hexadecyl-2-azelaoyl-sn-glycero-3-phosphocholine (azPC), an oxPL formed from alkyl phosphatidylcholines, is a potent peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonist. Although it has been reported that thiazolidinediones can induce volume expansion by enhancing renal sodium and water retention, the role of azPC, an endogenous PPAR{gamma} agonist, in renal transport functions is unknown. In the present study, we investigated the effect of azPC on renal proximal tubule (PT) transport using isolated PTs and kidney cortex tissues. We showed that azPC rapidly stimulated Na+/HCO3- cotransporter 1 activity and luminal Na+/H+ exchanger (NHE) activities in a dose-dependent manner, at submicromolar concentrations, in isolated PTs from rats and humans. Additionally, the stimulatory effects were completely blocked by a specific PPAR{gamma} antagonist, 2-chloro-5-nitro-N-phenylbenzamide (GW9662), and a mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitor, PD98059. Treatment with an siRNA against PPAR{gamma} significantly suppressed the expression of PPAR{gamma} mRNA, and it completely blocked the stimulation of both Na+/HCO3- cotransporter 1 and NHE activities by azPC. Moreover, azPC induced extracellular signal-regulated kinase (ERK) phosphorylation in rat and human kidney cortex tissues, and the induced ERK phosphorylation by azPC was completely suppressed by GW9662 and PD98059. These results suggest that azPC stimulates renal PT sodium-coupled bicarbonate transport via the PPAR{gamma}/MEK/ERK pathway. The stimulatory effects of azPC on PT transport may be partially involved in the development of volume expansion.

physiology↗