Biology subjects

Battulga, B.

Publications and source records attributed to Battulga, B..

3 recordsLinked to original sources

bioRxiv2025

Visualization and Morphological Analysis of Individual Oligodendrocytes in the Mouse White Matter

Myelin formation by oligodendrocytes is essential for the regulation of the conduction velocity and proper brain function. To ensure accurate information processing in response to experiences such as sensory stimuli and learning, oligodendrocytes adjust their number and morphology. In addition, oligodendrocyte morphology changes with senescence and in the presence of neurodegenerative diseases. Thus, visualizing oligodendrocytes and analyzing their morphology is crucial for understanding how our brains change under such conditions. Herein, we describe the methods for labeling and analyzing the morphologies of individual oligodendrocytes in mouse white matter at the light microscopic level. PDGFRa-CreERT2:Tau-mGFP and PLP-CreERT2:Tau-mGFP mice enable us to visualize and analyze later-born or early-born oligodendrocyte morphology. In addition, sparse oligodendrocyte labeling with attenuated rabies virus expressing GFP enables the visualization and morphological analysis of individual oligodendrocytes in various brain white matter regions without the need for transgenic animals. Furthermore, the combination with immunostaining in thick tissues enables the identification of labeled oligodendrocytes and myelin sheaths, as well as their interactions with neuronal axons. These methods are suitable for revealing how oligodendrocytes adapt their morphologies depending on environmental stimuli or pathological conditions.

neuroscience↗

bioRxiv2025

GABA mediates experience-dependent regulation of myelination in the mouse visual pathway.

Myelination in the visual pathway is critical for transmitting visual information from retina to the brain. Reducing visual experience shortens myelin sheath length and slows the conduction velocity of the optic nerve. However, the mechanism underlying such experience-dependent myelination is unclear. Here, we found that closing both eyes, binocular deprivation (BD), during the juvenile period less affects the optic nerve myelination than monocular deprivation (MD) via GABA signaling. RNA-seq analysis of optic nerves from MD and BD mice revealed that GABAergic signaling is downregulated on the deprived side of MD compared to the intact side and BD. Inhibition of GABAergic signaling during the juvenile period resulted in myelin sheath shortening and excessive oligodendrocyte generation in normal mice, similar to the changes observed in MD mice. Enhancing GABAergic signaling rescued the myelin sheath shortening and excessive oligodendrocyte generation in the optic nerve of MD mice. Furthermore, we identified novel GABAergic neurons located within the optic nerve, whose neurites form belt-like presynaptic structures with the oligodendrocyte lineage cells, suggesting a potential source of the GABAergic inputs into oligodendrocytes. Our results indicate that the myelination of visual pathway is maintained by binocular visual inputs via intra-nerve GABA signaling.

neuroscience↗

bioRxiv2023

Axonal selectivity of myelination by single oligodendrocytes established during development in mouse cerebellar white matter

Myelin formation by oligodendrocytes regulates conduction velocity and functional integrity of neuronal axons. While individual oligodendrocytes form myelin sheaths around multiple axons and control the functions of neural circuits in the brains, it remains unclear if oligodendrocytes selectively form myelin sheaths around the specific types of axons. In this study, we developed a method for observing a single oligodendrocyte and its myelin sheaths around different types of axons in the mouse cerebellar white matter. This was achieved by combining sparse fluorescent labeling of oligodendrocytes by attenuated rabies virus and subsequent immunostaining for axonal markers along with tissue clearing. We revealed that approximately half of the oligodendrocytes showed a preferential myelination of axons originating from Purkinje cells in the adult mice. The preference for Purkinje cell axons was more pronounced during development, when the process of myelination within cerebellar white matter was initiated; over 90% of oligodendrocytes preferentially myelinated the Purkinje cell axons. The transgenic mice that label early born oligodendrocytes showed that their myelin sheaths were predominantly formed around Purkinje cell axons in the adult cerebellar white matter. These results suggest that a significant proportion of oligodendrocytes preferentially myelinate functionally distinct axons in the cerebellar white matter, and the axonal preference of myelination is established during development.

neuroscience↗