Neuron mechanism of olfactory perception in mosquitoes

Mosquitoes are highly dependent on their olfactory system for chemical communication with the external environment including searching for foods, mating partners and oviposition sites. This article reviews the research progress on neuron projection mechanism of olfactory system to odor signals in mosquitoes. Olfactory appendages in moquitoes include antennae and maxillary palps that carry a variety of sensilla. Sensilla trichodea and sensilla grooved-peg in the antennae are sensitive to ammonia, L-lactic acid and carboxylic acids. The grooved peg sensilla in the maxillary palp are sensitive to carbon dioxide. These sensilla house olfactory receptor neurons (ORNs) in which olfactory receptor proteins are embedded. Host detection in mosquitoes starts with interactions between odorants and receptor proteins present on the dendritic membrane of the ORNs. ORNs are divided into different functional classes based on the response spectra to different odours. ORNs project to different glomerular areas of the antennal lobe (AL) in the deuterocerebrum of the central nervous system. The antennal lobe glomeruli in different response area are identified. The neuron signal is finally transduced to projection neuron (PN) in the potocerebrum and elicits the behaviour response of mosquitoes. These researches shed light on the neuron transduction channel of odor signal in olfactory system in mosquitoes. These results are very important for us to understand not only olfactory system in mosquitoes but also the odor perception mechanism of other insect species and human, and are helpful for further exploration in neuron science.