Related Experiment Video
Updated: Mar 21, 2026

Recording Temperature-induced Neuronal Activity through Monitoring Calcium Changes in the Olfactory Bulb of Xenopus laevis
Published on: June 3, 2016
The wiring diagram of a glomerular olfactory system
Matthew E Berck1,2, Avinash Khandelwal3,4, Lindsey Claus1,2
1Department of Physics, Harvard University, Cambridge, United States.
Abstract:
The sense of smell enables animals to react to long-distance cues according to learned and innate valences. Here, we have mapped with electron microscopy the complete wiring diagram of the Drosophila larval antennal lobe, an olfactory neuropil similar to the vertebrate olfactory bulb. We found a canonical circuit with uniglomerular projection neurons (uPNs) relaying gain-controlled ORN activity to the mushroom body and the lateral horn. A second, parallel circuit with multiglomerular projection neurons (mPNs) and hierarchically connected local neurons (LNs) selectively integrates multiple ORN signals already at the first synapse. LN-LN synaptic connections putatively implement a bistable gain control mechanism that either computes odor saliency through panglomerular inhibition, or allows some glomeruli to respond to faint aversive odors in the presence of strong appetitive odors. This complete wiring diagram will support experimental and theoretical studies towards bridging the gap between circuits and behavior.
Related Concept Videos
Olfaction
The olfactory receptors are embedded in the cilia of the...
Physiology of Smell and Olfactory Pathway
The olfactory...
Olfactory Receptors: Location and Structure
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking...
G-Protein Gated Ion Channels
Sensory...
Neural Circuits
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...

