Fine ultrastructural organization of glomerular neuropil in the developing zebrafish olfactory bulb
- 1Friedrich Miescher Institute for Biomedical Research
Abstract
Across animal phyla, odor information is represented in the first olfactory processing center by combinatorial activation of discrete glomeruli. To examine how this organization of olfactory processing channels emerges during development we combined 2-photon calcium imaging, volume electron microscopy, and large-scale automated neuron reconstruction in zebrafish larvae. We focused on a developmental stage (130 hours post fertilization) when the olfactory bulb (OB) is structured into ~16 large neuropil regions referred to as protoglomeruli but most glomeruli are not yet differentiated. Our ultrastructural reconstructions revealed that protoglomeruli are organized into smaller units referred to as microglomeruli, each of which is defined by a distinct set of mitral cells with overlapping, spatially confined dendritic arbors. Neighboring microglomeruli were innervated by distinct subsets of sensory axons and activity was more highly correlated among mitral cells associated with the same microglomerulus than across microglomeruli of the same or different protoglomeruli. These results reveal a precise subcellular organization of the neuropil in the developing OB into distinct processing channels, indicating that the layout of the adult glomerular array is established already early in development.
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BibTeX
@misc{crespo2026fine,
title = {{Fine ultrastructural organization of glomerular neuropil in the developing zebrafish olfactory bulb}},
author = {R. E. Montano Crespo and N. R. Moenig and J. M. Kappel and A. Graff Meyer and T. Gancarcik and M. Januszewski and R. W. Friedrich},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.18.752720},
url = {https://www.biorxiv.org/content/10.64898/2026.09.18.752720v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Fine ultrastructural organization of glomerular neuropil in the developing zebrafish olfactory bulb
AU - R. E. Montano Crespo
AU - N. R. Moenig
AU - J. M. Kappel
AU - A. Graff Meyer
AU - T. Gancarcik
AU - M. Januszewski
AU - R. W. Friedrich
PY - 2026
DA - 2026/09/18
PB - bioRxiv
DO - 10.64898/2026.09.18.752720
UR - https://www.biorxiv.org/content/10.64898/2026.09.18.752720v1
AB - Across animal phyla, odor information is represented in the first olfactory processing center by combinatorial activation of discrete glomeruli. To examine how this organization of olfactory processing channels emerges during development we combined 2-photon calcium imaging, volume electron microscopy, and large-scale automated neuron reconstruction in zebrafish larvae. We focused on a developmental stage (130 hours post fertilization) when the olfactory bulb (OB) is structured into ~16 large neuropil regions referred to as protoglomeruli but most glomeruli are not yet differentiated. Our ultrastructural reconstructions revealed that protoglomeruli are organized into smaller units referred to as microglomeruli, each of which is defined by a distinct set of mitral cells with overlapping, spatially confined dendritic arbors. Neighboring microglomeruli were innervated by distinct subsets of sensory axons and activity was more highly correlated among mitral cells associated with the same microglomerulus than across microglomeruli of the same or different protoglomeruli. These results reveal a precise subcellular organization of the neuropil in the developing OB into distinct processing channels, indicating that the layout of the adult glomerular array is established already early in development.
ER -