Language：English   Publishing type：Research paper (scientific journal)  

Neonatal organs are divided into those that are functionally complete at birth and those that are still developing. Postnatal retinal development varies depending on animal species, with altricial animals being underdeveloped and precocial animals born with vision. Comparing postnatal retinal growth in animals is predicted to reveal cellular and tissue changes necessary for visual function acquisition. In this study, retinal growth was examined from neonatal to adulthood and compared between mice (altricial) and cattle (precocial). Postnatal eyeballs showed rapid, then slow growth in both animals. The retina had a mature 10-layer structure after postnatal day 14 (P14) in mice. Retinal thickness increased from P0 to P14 and decreased sharply from P14 to P35. In the thickening phase, the elongation of the outer nuclear layer (ONL) and inner nuclear layer (INL) was remarkable, and axonal outgrowth in the rod bipolar cell was observed. In the thinning phase, a linear arrangement of the component cells was observed in the ONL, and cell numbers in the array decreased. In the cattle retina, the 10-layer structure was observed and a peak thickness at P0. Cattle retinas showed only the thinning phase after birth with tissue changes resembling those in the mouse retina. Retinal thinning observed at both newborns in mice and cattle seemed to reflect tissue reconstruction in axon and cellular arrangement, potentially being an important trait for functional visual development.

DOI： 10.1016/j.tice.2025.103188

PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

The wall of eyeball limits the penetration of the common fixatives, raising inadequate fixation or degeneration of internal tissue and posing challenges for preparing thin sections of the whole eyeball. In addition, many formaldehyde-containing fixatives exhibit the strong cross-linking effect that can excessively mask antigenic epitopes, thereby hampering immunological analyses. This study tried to develop an available fixative that exerts high permeability to mouse whole eyeballs and applicability to immunostaining. Glyoxal is known to have milder cross-linking capacity compared to formaldehyde, bringing better preservation of epitopes. We substituted the formaldehyde component in Davidson's solution with glyoxal and supplemented 1-butanol, methanol, 2-mercaptoethanol, and tris (2-carboxyethyl) phosphine hydrochloride (TCEP-HCl). Using modified fixatives and the GBMT solution, which was named by the initial letters of each component listed above, mouse eyeballs were immersion-fixed with the modified fixatives, and both tissue morphology and immunostaining quality were evaluated. The results showed that the GBMT solution prepared with glyoxal and specific combinations of additives improved morphological preservation of the eyeball tissues and enhanced immunofluorescence signals for certain cytoplasmic antigens, compared to the standard Davidson's solution. Our findings demonstrated that the successful development of a novel fixative enables both high-quality whole eyeball sectioning and improved immunostaining performance through immersion fixation alone.

DOI： 10.1292/jvms.25-0411

PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

The three-drug anesthetic mixture (medetomidine, midazolam and butorphanol), developed as an injectable anesthetic for laboratory animals, has been verified from various perspectives and applied to mice and other laboratory animals. However, the effects of its storage conditions and periods on its efficacy have not yet been studied. This study investigated the mixture's efficacy after storage under various conditions (room temperature, 4°C and -20°C) for 1 and 2 years. Mice in all groups were induced into a stable anesthetic state for at least 15 min after administration. The mice recovered from the anesthetized state 35 min after administration of the antagonist. These findings demonstrate the mixture's stability under different storage conditions and durations, potentially improving laboratory mouse welfare.

DOI： 10.1292/jvms.24-0516

PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

Exosomes or small extracellular vesicles (sEVs) are present in the blood of pregnant mice and considered to be involved in pregnancy physiology. Although sEVs in pregnant periods are proposed to be derived from placentas, sEVs-producing cells are not well known in mouse placentas. We studied the dynamics and localization of sEVs in pregnant serum and placentas, and examined gestational variation of microRNA (miRNA). Serums and placentas were collected from non-pregnant (NP) and pregnant mice throughout the entire gestational day (Gd). EVs were purified from serums and total RNA was isolated from EVs. Nanoparticle-tracking assay (NTA) revealed that the rates of sEVs in EVs are 53% at NP, and increased to 80.1% at Gd 14.5 and 97.5% at Gd 18.5. Western blotting on EVs showed positive reactivity to the tetraspanin markers and clarified that the results using anti-CD63 antibody were most consistent with the sEVs appearance detected by NTA. Serum EVs also showed a positive reaction to the syncytiotrophoblast marker, syncytin-1. Immunohistostaining using anti-CD63 antibody showed positive reactions in mouse placentas at the syncytiotrophoblasts and endothelial cells of the fetal capillaries. Quantitative PCR revealed that significantly higher amounts of miRNAs were included in the sEVs of Gd 18.5. Our results suggested that sEVs are produced in the mouse placenta and transferred to maternal or fetal bloodstreams. sEVs are expected to have a miRNA-mediated physiological effect and become useful biomarkers reflecting the pregnancy status.

DOI： 10.1292/jvms.24-0047

PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

The pecten is a fold-structured projection at the ocular fundus in bird eyes, showing morphological diversity between the diurnal and nocturnal species. However, its biological functions remain unclear. This study investigated the morphological and histological characteristics of pectens in wild birds. Additionally, the expression of non-visual opsin genes was studied in chicken pectens. These genes, identified in the chicken retina and brain, perceive light periodicity regardless of visual communication. Similar pleat numbers have been detected among bird taxa; however, pecten size ratios in the ocular fundus showed noticeable differences between diurnal and nocturnal birds. The pectens in nocturnal brown hawk owl show extremely poor vessel distribution and diameters compared with that of diurnal species. RT-PCR analysis confirmed the expression of Opn5L3, Opn4x, Rrh and Rgr genes. In situ hybridization analysis revealed the distribution of Rgr-positive reactions in non-melanotic cells around the pecten vessels. This study suggests a novel hypothesis that pectens develop dominantly in diurnal birds as light acceptors and contribute to continuous visual function or the onset of periodic behaviour.

DOI： 10.1111/ahe.13071

PubMed

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Language：Japanese   Publisher：佐賀 : 九州実験動物研究会  

CiNii Books

CiNii Research

J-GLOBAL

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Other Link： https://ndlsearch.ndl.go.jp/books/R000000004-I034420653

Language：Japanese   Publisher：(公社)日本獣医学会  

J-GLOBAL

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J-GLOBAL

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J-GLOBAL

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Language：Japanese   Publisher：(公社)日本獣医学会  

J-GLOBAL

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Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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