Publication Date:
2015-03-06
Description:
In Drosophila, just as in vertebrates, changes in external temperature are encoded by bidirectional opponent thermoreceptor cells: some cells are excited by warming and inhibited by cooling, whereas others are excited by cooling and inhibited by warming. The central circuits that process these signals are not understood. In Drosophila, a specific brain region receives input from thermoreceptor cells. Here we show that distinct genetically identified projection neurons (PNs) in this brain region are excited by cooling, warming, or both. The PNs excited by cooling receive mainly feed-forward excitation from cool thermoreceptors. In contrast, the PNs excited by warming ('warm-PNs') receive both excitation from warm thermoreceptors and crossover inhibition from cool thermoreceptors through inhibitory interneurons. Notably, this crossover inhibition elicits warming-evoked excitation, because warming suppresses tonic activity in cool thermoreceptors. This in turn disinhibits warm-PNs and sums with feed-forward excitation evoked by warming. Crossover inhibition could cancel non-thermal activity (noise) that is positively correlated among warm and cool thermoreceptor cells, while reinforcing thermal activity which is anti-correlated. Our results show how central circuits can combine signals from bidirectional opponent neurons to construct sensitive and robust neural codes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liu, Wendy W -- Mazor, Ofer -- Wilson, Rachel I -- R01 DC008174/DC/NIDCD NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Mar 19;519(7543):353-7. doi: 10.1038/nature14170. Epub 2015 Mar 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA. ; 1] Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA [2] Harvard NeuroDiscovery Center, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25739502" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Brain/*cytology/*physiology
;
Drosophila melanogaster/cytology/*physiology
;
Female
;
Interneurons/physiology
;
*Temperature
;
Thermoreceptors/*physiology
;
Thermosensing/*physiology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
