bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.03.19.643607

Heterogeneous distribution of glial cell marker proteins and of cell nucleus marker in the myelinated region of the normal rat optic nerve

KAWANO, J.
View original source ↗Export metadata ↓

Abstract

Glial cells play a critical role in the maintenance of neuronal activity in the optic nerve. The present study reports the distribution of glial structural proteins (GFAP: glial fibrillary acidic protein; MBP: myelin basic protein), a glial functional protein (GS: glutamine synthetase), and of a cell nuclear marker (bisBenzimide) in the various myelinated regions of the normal rat optic nerve. Fourteen optic nerves from 12 male Sprague-Dawley rats were used. Immunohistochemistry and confocal microscopy were employed to investigate the distribution of GFAP, MBP, GS, and of bisBenzimide along the longitudinal plane of the myelinated region. GFAP-immunoreactivity and GS-immunoreactivity were strong in the distal (anterior)-most part but weak in the proximal (posterior) part, demonstrating a significant decrease in strength along the longitudinal plane of the myelinated region. bisBenzimide labeling was also strong in the distal-most part but weak in the proximal part, indicating a significant difference in strength across the myelinated region. MBP-immunoreactive particles and cell nuclei were densely distributed in the distal-most part; however, they were sparsely dispersed in the proximal part, showing a significant difference. The heterogeneous distribution of GFAP, GS, bisBenzimide, cell nuclei, and of MBP-immunoreactive particles along the longitudinal plane may represent an important functional adaptation reflecting the non-uniform nature of the physiological and structural environment of the myelinated region. Notably, the concentrations of GFAP, GS, and of MBP-immunoreactive particles in the distal-most part of the myelinated region suggest that this area is under physiologically stressed conditions in the normal rat optic nerve. Key pointsO_LIThe present study reports the distribution of glial structural proteins (GFAP: glial fibrillary acidic protein; MBP: myelin basic protein), and of a glial functional protein (GS: glutamine synthetase) in the various myelinated regions of the normal rat optic nerve. C_LIO_LIGFAP-immunoreactivity and GS-immunoreactivity were strong in the distal (anterior)-most part but weak in the proximal (posterior) part. C_LIO_LIMBP-immunoreactive particles were densely distributed in the distal-most part; however, they were sparsely dispersed in the proximal part. C_LIO_LIThese results suggest that the distal-most part is not under physiological but rather under physiologically stressed conditions in the normal rat optic nerve. C_LI Graphical AbstractThe present study reports the distribution of glial structural pro-teins (GFAP: glial fibrillary acidic protein; MBP: myelin basic protein), and of a glial functional protein (GS: glutamine syn-thetase) in the various myelinated regions of the normal rat optic nerve. GF AP-immunoreactivity and GS-immunoreactivity were strong in the distal (anterior)-most part but weak in the proximal (poste-rior) part. MBP-immunoreactive particles were densely distributed in the distal-most part; however, they were sparsely dispersed in the proximal part. These results suggest that the distal-most part is not under physi-ological but rather under physiologically stressed conditions in the normal rat optic nerve. O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/643607v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@54c666org.highwire.dtl.DTLVardef@1ad8f3borg.highwire.dtl.DTLVardef@196870borg.highwire.dtl.DTLVardef@17c1641_HPS_FORMAT_FIGEXP M_FIG C_FIG

Explore related subjects

neurosciencePreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

KAWANO, J.. 2025-03-19. Heterogeneous distribution of glial cell marker proteins and of cell nucleus marker in the myelinated region of the normal rat optic nerve. https://doi.org/10.1101/2025.03.19.643607

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Connexin 40 deficiency alters the temporal profile of postictal oxygen dynamics following focal seizures.

Epilepsy is increasingly recognized as a disorder involving both neuronal and vascular dysfunction. While connexin signaling has been implicated in epileptogenesis, the contribution of vascular connexins to seizure associated cerebrovascular pathology remains poorly understood. Connexin40 (Cx40) is an endothelial gap junction protein that plays a crucial role in vascular communication and blood-flow regulation. Seizures induce dynamic changes in cerebral perfusion and oxygenation, including prolonged postictal hypoperfusion/hypoxia. To determine whether Cx40 influences postictal hypoxia following focal seizures, we examined seizure characteristics and postictal oxygen dynamics in Cx40 knockout (Cx40-/-) mice using an established focal hippocampal seizure model. Electrically kindled seizures were elicited in wild-type and Cx40-/- mice, and local hippocampal tissue oxygenation was continuously monitored before and after seizure induction. Seizure duration did not differ between genotypes, indicating comparable seizure severity. Interestingly, Cx40 deletion altered the temporal pattern of postictal oxygen recovery, producing greater early hypoxia and a delayed secondary rebound in pO2 despite similar peak oxygen levels and overall hypoxic burden. These findings demonstrate that loss of Cx40 selectively alters the temporal profile of postictal oxygen dynamics without affecting seizure duration. Taken together, the results suggest that endothelial gap junctional communication contributes to postictal vascular recovery and identify Cx40 as a potential modulator of seizure associated neurovascular dysfunction.

neuroscience↗
bioRxiv2026

Attention Across Scales: From Individual Variation to Social Hierarchies and Brain Networks in Semi-Free-Ranging Macaques

Attention is a fundamental brain function supporting perception, decision-making, and social behavior, and its dysfunction profoundly impairs daily life. It is both dynamic and stable, varying across observations and individuals, changing across the lifespan, and being shaped by social and environmental experience. Yet capturing this complexity remains a central challenge in neuroscience. Here, we integrated longitudinal behavioral assessments of semi-free-ranging macaques living in naturalistic social groups with resting-state fMRI. We quantified performance across days, ages, and social hierarchies and related it to intrinsic brain organization. Distinct attentional phenotypes emerged, including individuals with reduced attentional control. Performance followed an inverted-U lifespan trajectory, improving from childhood to adulthood before declining. Social status modulated attentional performance. Critically, nonlinear lifespan trajectories and associations with individual attentional differences were most clearly expressed in frontoparietal connectivity. Together, these findings reveal how sustained attention is organized across scales, providing a biological framework for its individual diversity, social modulation, and neural basis.

neuroscience↗
bioRxiv2026

Decoding natural scenes from patterned optogenetic responses in mouse visual cortex

A central challenge in developing visual cortical prostheses is to determine how visual stimuli should be transformed into effective patterns of cortical stimulation. Although advances in stimulation technologies, including optogenetics, provide increasingly precise control over cortical activity, it remains unclear whether artificially evoked activity can reproduce the information content of naturally evoked visual representations. Here we establish a quantitative framework for evaluating visual encoding strategies by decoding cortical responses evoked by natural vision and patterned optogenetic stimulation. We developed a novel dual-modal paradigm in awake mice to bridge the gap between endogenous photostimulation and artificial network driving. By co-expressing the high-performance calcium indicator GCaMP6s and the red-shifted, ultra-sensitive opsin rsChRmine-oScarlet in the primary visual cortex (V1), we successfully translated dynamic natural movie frames into patterned, spatiotemporal optogenetic stimulation. Quantitative comparisons of macro-scale dynamics demonstrated that this patterned optogenetic injection evokes cortical states highly comparable and representationally aligned with those driven by actual visual photostimulation. To systematically evaluate the fidelity of these responses, we developed STAR, a deep learning model featuring spatial and temporal attention mechanisms, and successfully reconstructed the frames of natural movies from V1 signals under both experimental modalities. Collectively, our results demonstrate that complex sensory information can be both naturally encoded and synthetically injected into V1 circuits with high decoding fidelity. This work provides an empirical and computational proof-of-concept for intelligent, closed-loop biomimetic encoders, establishing a robust framework for next-generation cortical visual neuroprostheses and bidirectional brain-machine interfaces.

neuroscience↗