Antennation

Janus integer APOIDEA CW Produced only in females and antennally active only in males (9Z)-Octadec-9-en-4-olide 7 [33]... 

Several long-range attractant sex pheromones have been identified (Table 3) or evidence for such a pheromone has been obtained in the past 13 years. The parasitoid Ascogaster reticulatus produces (9Z)-hexadec-9-enal 9 in a tibial gland [47]. The pheromone is spread by the females much like a trail on the substrate, and the males follow the mark to the source by close antennal contact with the substrate [48]. EAG studies have revealed that the males respond much more strongly to (9Z)-hexadec-9-enal than the females and that the response to the... 

Atta texana W- Antennal response of previously identified trail pheromone component Methyl 4-methylpyrrole-2-carboxylate 64 [164]... 

Formica fusca W-HG Trail following antennal responses (3R)-(-)-3,4- Dihydro - 8 -hydroxy-3,5,7-trimethylisocoumarin 121 [172,173]... 

Leptogenys diminuta W-PG Trail following antennal responses (3 R,4S)-4-Methylheptan-3-ol 67 [176,177]... 

W-PyG Antennal response of previously identified recruitment pheromone cz s-Isogeraniol 135 [177]... 

Pristomyrmex pungens W-PG Trail following antennal response Deca-2,4-dien-5-olide 141 [185]... 

Protozoan, Cristigera sp. 150 pg/L for 12 h alterations in antennal gland BCF 2760 for antennal gland, and 58 for gill Reduced growth 3... 

Further data showed HD to have a direct stimulatory effect on the female. When quiescent females were stroked with excised coremata, they tended to present their abdomen, but only if the coremata contained HD. Moreover, to elicit maximal effect, the HD had to be of the absolute configuration [R(—)] in which the compound occurs in the coremata (19). Predictably, female Utetheisa were found to have antennal chemorecep-tors highly sensitive to the R(-) isomer of HD (21). 

Axons of antennal ORCs project through the antennal nerve to enter the brain at the level of the ipsilateral antennal lobe (AL) of the deutocerebrum (52). ORC axons project from the flagellum to targets in the AL, but axons from antennal mechanosensory neurons bypass the AL and project instead to an "antennal mechanosensory and motor center" in the deutocerebrum posteroventral (with respect to the body axis of the animal) to the AL (52, 58, 64). In moths and certain other insect groups, sex-pheromonal information is processed in a prominent male-specific neuropil structure in each AL called the macroglomerular complex (MGC) (16, 52, 64, 65). 

Axons of male-specific antennal ORCs specialized to detect components of the sex pheromone project exclusively to the MGC (64, 89), and all AL neurons that respond to antennal stimulation with sex pheromone components have arborizations in the MGC (65, 72, 73). The MGC in M. sexta has two major, easily distinguishable divisions a donut-shaped neuropil structure (the "toroid") and a globular structure (the "cumulus") adjacent to the toroid and closer to the entrance of the antennal nerve into the AL (74). AL PNs that respond to antennal stimulation with sex pheromone component A have arborizations in the toroid and PNs responsive to component B, in the cumulus (74). Thus first-order synaptic processing of sensory information about these key components of the sex pheromone apparently is confined to different, distinctive neuropil regions of the MGC. 

By means of intracellular recording and staining methods, we have examined the responses of AL neurons to stimulation of the ipsilateral antenna with each of the sex pheromone components as well as partial and complete blends (75). In accordance with results of behavioral and sensory-receptor studies, components A and B are the most effective and potent sex pheromone components for eliciting physiological responses in the male-specific AL neurons. On the basis of these responses, we classified the neurons into two broad categories pheromone generalists and pheromone specialists (76). Pheromone generalists are neurons that respond similarly to stimulation of either the component A input channel or the component B input channel and do not respond differently when the complete, natural pheromone blend is presented to the antenna. In contrast, pheromone specialists are neurons that can discriminate between antennal stimulation with component A and stimulation with component B. There are several types of pheromone specialists. Some... 

An important subset of pheromone-specialist PNs in male M. sexta receives input from both component A and component B input channels, described above, but the physiological effects of the two inputs are opposite (72). That is, if antennal stimulation with component A leads to excitation, then stimulation with component B inhibits the intemeuron, and vice versa. Simultaneous stimulation of the antenna with both components A and B elicits a mixed inhibitory and excitatory response in these special PNs. Thus these neurons can discriminate between the two inputs based upon how each affects the spiking activity of the cell. These PNs also respond uniquely to the natural pheromone blend released by the female these pheromone specialist neurons have enhanced ability to follow intermittent pheromonal stimuli occurring at natural frequencies of 10 stimuli per sec (77). 

The male moth s pheromone-analyzing olfactory subsystem is composed of pheromone-specific antennal ORCs projecting to the similarly specialized, anatomically defined MGC in the AL and MGC output neurons that project to olfactory foci in the protocerebrum. This subsystem is an example of a labeled-line pathway (18). Its specialization to detect, amplify, and analyze features of sex-pheromonal signals and its consequent exaggeration of common olfactory organizational principles... 

Fig-1 Schematic view of the overall olfactory processing in insects. Pheromones and other semiochemicals are detected by specialized sensilla on the antennae, where the chemical signal is transduced into nervous activity. The olfactory receptor neurons in the semiochemi-cal-detecting sensilla are connected directly to the antennal lobe. Here the semiochemical-derived electrical signals are processed and sent out (through projection neurons) to the protocerebrum. Olfactory information is then integrated with other stimulus modalities, a decision is made, and the motor system is told what to do... 

The distal part of these receptor cells, the dendrites (0.1-0.5 pm in diameter), extend into the hair lumen (Fig. 3), whereas their axons are connected directly to the antennal lobes in the brain where they make the first synaptic contacts. In the giant silkmoth, Antheraeapolyphemus,for example, each male... 

Using a specific antibody, Shanbhag and collaborators [34] demonstrated that LUSH is expressed in sensilla trichodea of the Drosophila antennae along with two other putative odorant-binding proteins Obp83a (PBPRP-3, OS-F) and Obp83b (OS-E). When antennal sections of the LUSH-deficient mutant were la-... 

---