Mu et al 2014.pdf (4.77 MB)
Responses of Drosophila giant descending neurons to visual and mechanical stimuli
journal contribution
posted on 2023-06-09, 02:07 authored by Laiyong Mu, Jonathan Bacon, Kei Ito, Nicholas J StrausfeldIn Drosophila, the paired giant descending neurons (GDNs), also known as giant fibers, and the paired giant antennal mechanosensory descending neurons (GAMDNs), are supplied by visual and mechanosensory inputs. Both neurons have the largest cell bodies in the brain and both supply slender axons to the neck connective. The GDN axon thereafter widens to become the largest axon in the thoracic ganglia, supplying information to leg extensor and wing depressor muscles. The GAMDN axon remains slender, interacting with other descending neuron axons medially. GDN and GAMDN dendrites are partitioned to receive inputs from antennal mechanosensory afferents and inputs from the optic lobes. Although GDN anatomy has been well studied in Musca domestica, less is known about the Drosophila homolog, including electrophysiological responses to sensory stimuli. Here we provide detailed anatomical comparisons of the GDN and the GAMDN, characterizing their sensory inputs. The GDN showed responses to light-on and light-off stimuli, expanding stimuli that result in luminance decrease, mechanical stimulation of the antennae, and combined mechanical and visual stimulation. We show that ensembles of lobula columnar neurons (type Col A) and mechanosensory antennal afferents are likely responsible for these responses. The reluctance of the GDN to spike in response to stimulation confirms observations of the Musca GDN. That this reluctance may be a unique property of the GDN is suggested by comparisons with the GAMDN, in which action potentials are readily elicited by mechanical and visual stimuli. The results are discussed in the context of descending pathways involved in multimodal integration and escape responses.
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Publication status
- Published
File Version
- Published version
Journal
Journal of Experimental BiologyISSN
0022-0949Publisher
Company of BiologistsExternal DOI
Issue
12Volume
217Page range
2121-2129Department affiliated with
- Evolution, Behaviour and Environment Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2016-07-11First Open Access (FOA) Date
2016-07-11First Compliant Deposit (FCD) Date
2016-07-11Usage metrics
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