# Biased randomness: a fundamental connectivity mechanism for associative brain centers.

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2024 · $452,629

## Abstract

PROJECT SUMMARY
Uncovering fundamental mechanisms of neuronal connectivity that enable associative brain centers to learn
efficiently is an important goal of neuroscience. In the mushroom body — the associative brain center in
Drosophila melanogaster — the constituent Kenyon cells receive input from olfactory projection neurons. Each
projection neuron connects to one of the 51 glomeruli forming the antennal lobe, the primary olfactory processing
center in the Drosophila brain. Our previous work has shown that these connections are random in that there
are no sets of glomeruli converging preferentially onto a given Kenyon cell. However, the glomeruli are not
represented with equal frequency among Kenyon cell inputs. Certain glomeruli are significantly overrepresented
or underrepresented, even though a uniform distribution would be optimal for learning performance. We are
proposing to test the hypothesis that this non-uniform distribution — which we call 'biased randomness' — serves
an important biological function, namely to predispose the learning ability of the mushroom body towards certain
ethologically pertinent stimuli. To test this hypothesis, we will first compare the representation of individual
glomeruli in different Drosophila populations that have evolved in different environments in order to investigate
whether there are correlations between biases and known differences in chemosensory ecology (Aim 1).
Second, molecular regulators of glomerular representation will be identified in Drosophila melanogaster to
manipulate the representation of individual glomeruli and test for effects on olfactory representation in the
mushroom body and learning (Aim 2). The research in this proposal has the potential to reveal a fundamental
mechanism by which neuronal connectivity is fine-tuned to predispose learning towards particularly pertinent
stimuli and that underlies the evolution of neuronal circuit architecture in different chemosensory environments.

## Key facts

- **NIH application ID:** 10979954
- **Project number:** 2R01NS107970-06A1
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Sophie Caron
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $452,629
- **Award type:** 2
- **Project period:** 2018-07-01 → 2029-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10979954

## Citation

> US National Institutes of Health, RePORTER application 10979954, Biased randomness: a fundamental connectivity mechanism for associative brain centers. (2R01NS107970-06A1). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/10979954. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*