Mapping the Brain

NEUROSCIENCE NEWS  AUGUST 9, 2017

Summary: Researchers have constructed a detailed brain map of the mushroom body in the fruit fly brain. The mushroom body is implicated in creating and storing memories for sensory information.

Source: University of Konstanz.

Researchers from the University of Konstanz contribute in constructing the first circuit map of a brain’s learning and memory center.

In the past several years, and in close cooperation with the Janelia Research Campus of the Howard Hughes Medical Institute in Virginia, these neurobiologists used high resolution 3D electron microscopy to reconstruct nerve cells and their individual connections via synapses. The examination of this circuit will be instrumental in guiding future research on how the brain learns new things and then stores these as memories.

The research results were published in the 10 August 2017 edition of the journal “Nature”under the title: “The complete connectome of a learning and memory center in an insect brain”

Katharina Eichler manually recorded all of the approximate four hundred cells and reconstructed every one of the roughly one hundred thousand synapses in a microscopically photographed larval brain. The research carried out by the researchers at the University of Konstanz represents a significant contribution towards the overall aim of the international collaboration project led by Dr. Albert Cardona from the Janelia Research Campus: to create a complete wiring diagram of the entire brain of Drosophila larvae.

Towards this end, researchers in more than 20 labs from around the world are collaborating to reconstruct all of the 10,000 nerve cells. With the modelling of the mushroom body, the researchers from Konstanz have reconstructed almost 8,000 cells of this multi-purpose brain structure.

In the next two to three years, all of the connections within the insect brain will be mapped out.

“The brain’s mushroom body is also its memory centre in which sensory information is collected and memory is created. It is therefore essential for understanding the brain. Not only were we able to completely reconstruct this crucial component of the brain, but we also documented the existence of new circuit connection patterns between individual cells,” says Andreas Thum about the successful research being carried out at the University of Konstanz.

These new circuit connection patterns are already serving as the basis for additional research projects.

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Collaboration partners:

Albert Cardona, Marta Zlatic and James W. Truman, Janelia Research Campus of the Howard Hughes Medical Institute (Virginia, USA)

Bertram Gerber, Leibniz Institute for Neurobiology (Magdeburg, Germany)

Larry Abbott, Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University (New York, USA)

Funding: The project was funded by the German Research Foundation (DFG), the German Academic Exchange Service (DAAD), Research Campus Janelia’s Visiting Scientist Program, the Baden-Württemberg Foundation and the Zukunftskolleg of the University of Konstanz.

Source: Julia Wandt – University of Konstanz
Image Source: NeuroscienceNews.com image is credited to the researchers/University of Konstanz.

Original Research: Abstract for “The complete connectome of a learning and memory centre in an insect brain” by Katharina Eichler, Feng Li, Ashok Litwin-Kumar, Youngser Park, Ingrid Andrade, Casey M. Schneider-Mizell, Timo Saumweber, Annina Huser, Claire Eschbach, Bertram Gerber, Richard D. Fetter, James W. Truman, Carey E. Priebe, L. F. Abbott, Andreas S. Thum, Marta Zlatic & Albert Cardona in Nature. Published online August 9 2017 doi:10.1038/nature23455

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Abstract

The complete connectome of a learning and memory centre in an insect brain

Associating stimuli with positive or negative reinforcement is essential for survival, but a complete wiring diagram of a higher-order circuit supporting associative memory has not been previously available. Here we reconstruct one such circuit at synaptic resolution, the Drosophila larval mushroom body. We find that most Kenyon cells integrate random combinations of inputs but that a subset receives stereotyped inputs from single projection neurons. This organization maximizes performance of a model output neuron on a stimulus discrimination task. We also report a novel canonical circuit in each mushroom body compartment with previously unidentified connections: reciprocal Kenyon cell to modulatory neuron connections, modulatory neuron to output neuron connections, and a surprisingly high number of recurrent connections between Kenyon cells. Stereotyped connections found between output neurons could enhance the selection of learned behaviours. The complete circuit map of the mushroom body should guide future functional studies of this learning and memory centre.

“The complete connectome of a learning and memory centre in an insect brain” by Katharina Eichler, Feng Li, Ashok Litwin-Kumar, Youngser Park, Ingrid Andrade, Casey M. Schneider-Mizell, Timo Saumweber, Annina Huser, Claire Eschbach, Bertram Gerber, Richard D. Fetter, James W. Truman, Carey E. Priebe, L. F. Abbott, Andreas S. Thum, Marta Zlatic & Albert Cardona in Nature. Published online August 9 2017 doi:10.1038/nature23455

http://neurosciencenews.com/learning-memory-brain-mapping-7270/