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

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2020 · $333,594

## Abstract

SUMMARY
Uncovering fundamental mechanisms of neuronal connectivity that enable associative brain centers to learn is
an important goal of neuroscience. In the Drosophila melanogaster mushroom body, the constituent Kenyon
cells receive input from olfactory projection neurons. Each projection neuron connects to one of the 50 glomeruli
in the antennal lobe, the primary olfactory processing center. 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 idea that this non-uniform distribution, which we termed
‘biased randomness’, serves an important function, namely to predispose the learning ability of an associative
brain center towards certain ethologically pertinent stimuli. To test this idea, first, the representation of individual
glomeruli will be compared in three different Drosophila species and investigated for correlations to differences
in chemosensory ecology (Specific Aim 1). Second, molecular regulators of glomerular representation will be
identified in D. melanogaster to manipulate the representation of individual glomeruli and test for effects on
olfactory representation in the mushroom body and learning (Specific 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, thus possibly accounting for cognitive biases.
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## Key facts

- **NIH application ID:** 9967167
- **Project number:** 5R01NS107970-03
- **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:** 2020
- **Award amount:** $333,594
- **Award type:** 5
- **Project period:** 2018-07-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9967167

## Citation

> US National Institutes of Health, RePORTER application 9967167, Biased randomness: a fundamental connectivity mechanism for associative brain centers (5R01NS107970-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9967167. Licensed CC0.

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