Fig. 4.
Odor coding by a receptor repertoire. (A) Combinatorial coding of odors by receptors of the Drosophila larva. Colored dots indicate a strong odor response, defined as ≥100 spikes/s to a 10−2 dilution in the empty neuron system. Reprinted from ref. 20 with permission from Elsevier. (B) Tuning curves for a narrowly tuned receptor, Or82a, and a broadly tuned receptor, Or67a. The 110 odorants are listed along the x axis according to the magnitudes of the responses that they elicit from each receptor. The odorants that elicit the strongest responses are placed near the center of the distribution, whereas those odorants eliciting weak responses are at the edges. The order of odors is different for the two receptors. Negative values represent inhibitory responses. Reprinted from ref. 73 with permission from Elsevier.