Fig. 1.

Depiction of mosquito olfactory receptor neuron (ORN) responses. (A) ORN response to the attractant 1-octen-3-ol, and to 1-octen-3-ol plus DEET, introduced into the airflow from a single odor cartridge, giving the impression that DEET causes ORN inhibition, as stated by Ditzen et al. (4). (B and C) However, according to Syed and Leal (5), a separate DEET ORN is responsible for repellency (B), and, when 1-octen-3-ol and DEET are introduced into the airflow from two different odor cartridges, no ORN inhibition occurs (C).