Spontaneous neural activity in the developing ant olfactory system
Abstract
Spontaneous neural activity is a pillar of mammalian neurodevelopment. In mammals, developing olfactory sensory neurons (OSNs) show spontaneous activity patterns that depend on the olfactory receptor (OR) they express. This activity is necessary for proper sorting of OSN axons into olfactory bulb glomeruli. This contrasts with the simpler olfactory system of the fruit fly Drosophila melanogaster, where antennal lobe glomeruli form without functional ORs. Compared to Drosophila, ants have a vastly expanded olfactory system and, unlike Drosophila, require functional ORs for proper development. This raises the possibility that ants, like mammals, rely on spontaneous neural activity. To test whether developing ant OSNs are spontaneously active, we performed live calcium imaging in translucent pupae of the clonal raider ant Ooceraea biroi, using a transgenic line expressing the genetically encoded calcium indicator GCaMP6s in OSNs. Developing O. biroi OSNs exhibit spontaneous calcium transients from the earliest stages of glomerulus formation, and features of this activity change over the course of metamorphosis. During early stages, activity is faster, varies widely between cells, and is uncorrelated across the OSN population. By mid-metamorphosis, activity has slowed, with longer calcium events and fewer peaks per cell. As pupae approach eclosion, a new mode appears, with rhythmic, sawtooth-shaped calcium events that synchronously engage OSNs in both antennae. This stage-dependent spontaneous activity suggests that the expanded ant olfactory system may use a developmental logic more akin to mammals than to Drosophila.
Related
- Acetylcholine mediates behavioral state-dependent modulation of spontaneous activity in the developing mouse visual cortex
- Developmental interactions between oscillatory and spontaneous neural activity support improvements in inhibitory control from adolescence into adulthood
- Fine ultrastructural organization of glomerular neuropil in the developing zebrafish olfactory bulb
- Positive early-life olfactory memory is rooted in the olfactory bulb and triggers large-scale changes beyond the olfactory system
- Immature olfactory sensory neurons provide complementary input in the intact olfactory system.
BibTeX
@misc{frank2026spontaneous,
title = {{Spontaneous neural activity in the developing ant olfactory system}},
author = {Dominic D Frank and Daniel J. C. Kronauer},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.25.761666},
url = {https://www.biorxiv.org/content/10.64898/2026.10.25.761666v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Spontaneous neural activity in the developing ant olfactory system
AU - Dominic D Frank
AU - Daniel J. C. Kronauer
PY - 2026
DA - 2026/10/25
PB - bioRxiv
DO - 10.64898/2026.10.25.761666
UR - https://www.biorxiv.org/content/10.64898/2026.10.25.761666v1
AB - Spontaneous neural activity is a pillar of mammalian neurodevelopment. In mammals, developing olfactory sensory neurons (OSNs) show spontaneous activity patterns that depend on the olfactory receptor (OR) they express. This activity is necessary for proper sorting of OSN axons into olfactory bulb glomeruli. This contrasts with the simpler olfactory system of the fruit fly Drosophila melanogaster, where antennal lobe glomeruli form without functional ORs. Compared to Drosophila, ants have a vastly expanded olfactory system and, unlike Drosophila, require functional ORs for proper development. This raises the possibility that ants, like mammals, rely on spontaneous neural activity. To test whether developing ant OSNs are spontaneously active, we performed live calcium imaging in translucent pupae of the clonal raider ant Ooceraea biroi, using a transgenic line expressing the genetically encoded calcium indicator GCaMP6s in OSNs. Developing O. biroi OSNs exhibit spontaneous calcium transients from the earliest stages of glomerulus formation, and features of this activity change over the course of metamorphosis. During early stages, activity is faster, varies widely between cells, and is uncorrelated across the OSN population. By mid-metamorphosis, activity has slowed, with longer calcium events and fewer peaks per cell. As pupae approach eclosion, a new mode appears, with rhythmic, sawtooth-shaped calcium events that synchronously engage OSNs in both antennae. This stage-dependent spontaneous activity suggests that the expanded ant olfactory system may use a developmental logic more akin to mammals than to Drosophila.
SN - 2692-8205
ER -