Format

Send to

Choose Destination
Elife. 2018 Aug 2;7. pii: e38554. doi: 10.7554/eLife.38554.

MDN brain descending neurons coordinately activate backward and inhibit forward locomotion.

Author information

1
Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States.
2
Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.
#
Contributed equally

Abstract

Command-like descending neurons can induce many behaviors, such as backward locomotion, escape, feeding, courtship, egg-laying, or grooming (we define 'command-like neuron' as a neuron whose activation elicits or 'commands' a specific behavior). In most animals, it remains unknown how neural circuits switch between antagonistic behaviors: via top-down activation/inhibition of antagonistic circuits or via reciprocal inhibition between antagonistic circuits. Here, we use genetic screens, intersectional genetics, circuit reconstruction by electron microscopy, and functional optogenetics to identify a bilateral pair of Drosophila larval 'mooncrawler descending neurons' (MDNs) with command-like ability to coordinately induce backward locomotion and block forward locomotion; the former by stimulating a backward-active premotor neuron, and the latter by disynaptic inhibition of a forward-specific premotor neuron. In contrast, direct monosynaptic reciprocal inhibition between forward and backward circuits was not observed. Thus, MDNs coordinate a transition between antagonistic larval locomotor behaviors. Interestingly, larval MDNs persist into adulthood, where they can trigger backward walking. Thus, MDNs induce backward locomotion in both limbless and limbed animals.

KEYWORDS:

D. melanogaster; backward crawl; behavior; command neuron; descending neuron; locomotor; neural circuit; neuroscience

PMID:
30070205
PMCID:
PMC6097840
DOI:
10.7554/eLife.38554
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for eLife Sciences Publications, Ltd Icon for PubMed Central
Loading ...
Support Center