. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DYNAMIC CODES FOR ODORS 71 work is not cited and discussed here, and rather send readers to several excellent recent reviews on related and overlapping topics (Cinelli and Kauer, 1992; Freeman, 1992; Gray, 1994; Axel. 1995; Hildebrand, 1995; Ham- mer and Menzel, 1995; Singer and Gray, 1995). same time, or in the same way. We consider here two important and overlapping aspects of these response pat- terns: first, the slow and odor-specific temporal patterns of activity; second, the synchrony of firing and the oscil- lations o
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DYNAMIC CODES FOR ODORS 71 work is not cited and discussed here, and rather send readers to several excellent recent reviews on related and overlapping topics (Cinelli and Kauer, 1992; Freeman, 1992; Gray, 1994; Axel. 1995; Hildebrand, 1995; Ham- mer and Menzel, 1995; Singer and Gray, 1995). same time, or in the same way. We consider here two important and overlapping aspects of these response pat- terns: first, the slow and odor-specific temporal patterns of activity; second, the synchrony of firing and the oscil- lations of local field potential (Fig. 1). Odor Representation in the Locust Olfactory System In this section we review our main electrophysiologi- cal findings and derive from them a hypothesis for odor- coding, which might be applied to olfactory systems other than those of insects. When an odor (for example a pine fragrance) reaches the antenna of a locust (Schisto- cerca amcricana), a subset of the ca. 300 local and 850 projection neurons in the ipsilateral antennal lobe is ac- tivated. This subset may comprise 10% to 20% of the to- tal complement of neurons in the antennal lobes. These activated neurons do not, however, all respond at the Slow, odor-specific response patterns When an odor is delivered to the antenna, some pro- jection neurons fire fora few hundred milliseconds at the onset of the stimulus, while others fire only after a cer- tain, consistent delay (from 10 to several hundred milli- seconds). Other projection neurons yet may fire during 2 (or more) distinct epochs but remain silent in between. In other words, the ensemble of neurons that fire simul- taneously (, within any 100-ms period of the ensem- ble response) changes as time progresses. This progres- sive change in the ensemble activated by an odor, how- ODOR CO s WO <o GC 0. apple T [1,2,4,7,9,11] [3,5,11,12] [1,6,8,10,12] B lavender. Please note that these images are extracted from scanned page images
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
