Larvae shun the light

June 22, 2009,

Drosophila larvae avoid light during the foraging stage of their development. Research published in the open access journal BMC Neuroscience shows that both 5-HT (serotonergic) and corazonergic neurons have a role in regulating this behavior.

To identify which modulate the larvae's photobehavior, Verónica G. Rodriguez Moncalvo and Ana Regina Campos from McMaster University, Ontario, Canada analysed Drosophila which had been genetically engineered to achieve suppressed synaptic transmission in candidate neurons. Muted synaptic transmission can be achieved by targeted expression of tetanus toxin light chain (TNT), as when made in neurons TNT suppresses evoked and spontaneous neurotransmitter release. The authors looked first at larvae in which dopaminergic, serotonergic and corazonergic neurons had been silenced by using the DOPA decarboxylase (Ddc) promoter to drive TNT expression, and subsequently at larvae expressing constructs with more specific promoters, in which different subsets of Ddc neurons were muted. Larvae with and without the function of these neurons were put through their paces in light and dark conditions.

The results show that inactivation of Ddc neurons increases the aversion to light, both during the foraging phase, when larvae are characteristically photophobic, and the later stages of development, when larvae are usually photoneutral. Both 5-HT neurons and corazonergic neurons, but not dopaminergic neurons, contribute to light-controlled larval locomotion, and this is modulated at least partly by 5-HT neurons located in the brain hemispheres. However, this modulation does not appear to occur at the photoreceptor level and may be mediated by 5-HT1ADro receptors. These findings may provide clues to help identify the target neurons of the serotonin signalling, which the authors believe could be critical for light-controlled movement.

"These findings provide new insights into the function of 5-HT neurons in Drosophila larval behavior, as well as into the mechanisms underlying regulation of larval response to light," says Campos.

More information: Role of serotonergic neurons in the Drosophila larval response to light, Veronica G Rodriguez Moncalvo and Ana REGINA Campos, BMC Neuroscience (in press), www.biomedcentral.com/bmcneurosci/

Source: BioMed Central (news : web)

Related Stories

Recommended for you

Your brain responses to music reveal if you're a musician or not

January 23, 2018
How your brain responds to music listening can reveal whether you have received musical training, according to new Nordic research conducted in Finland (University of Jyväskylä and AMI Center) and Denmark (Aarhus University).

New neuron-like cells allow investigation into synthesis of vital cellular components

January 22, 2018
Neuron-like cells created from a readily available cell line have allowed researchers to investigate how the human brain makes a metabolic building block essential for the survival of all living organisms. A team led by researchers ...

Finding unravels nature of cognitive inflexibility in fragile X syndrome

January 22, 2018
Mice with the genetic defect that causes fragile X syndrome (FXS) learn and remember normally, but show an inability to learn new information that contradicts what they initially learned, shows a new study by a team of neuroscientists. ...

Epilepsy linked to brain volume and thickness differences

January 22, 2018
Epilepsy is associated with thickness and volume differences in the grey matter of several brain regions, according to new research led by UCL and the Keck School of Medicine of USC.

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.