Olfactory responses recorded from sensilla coeloconica of the silkmoth Bombyx mori

Abstract

Abstract. Extracellular single sensillum recordings were made from the double‐walled multiporous sensilla coeloconica on the antennae of males and females of Bombyx mori L. (Lepidoptera: Bombycidae). The receptor neurones responded to olfactory stimuli; no thermo‐ or hygroreceptors were found. Many neurones responded with a decrease of the transepithelial potential and increased rates of nerve impulses to aliphatic hydrocarbons with chain lengths between three and ten carbon atoms. Most abundant were neurones responding best to acids and aldehydes. Receptor neurones responding with a low threshold to only one acid of a certain chain length were considered as specialists. In some sensilla an increase of the transepithelial potential combined with nerve impulse inhibition was observed in response to monoterpene alcohols. Neurones responding with excitation to aliphatic acids and with inhibition to terpenes were found in the same sensilla. Some neurones excited by aliphatic acids were inhibited by terpenes. Responses to headspace volatiles of mulberry leaves, the larval food, were also obtained. Therefore the coeloconic sensilla may be involved in the selection of oviposition sites.

Ultrastructure and receptor cell responses of the antennal grooved peg sensilla of Triatoma infestans (Hemiptera: Reduviidae)

“…This is comparable to the results reported from the dw sensilla in Aedes responding to lactic acid (Davis, 1977;Davis and Sokolove, 1976), in Locusta to green leaf volatiles such as hexenal, hexanol and aliphatic organic acids with a chain length of 3-8 carbons (Boeckh, 1967;Kafka, 1970), and in Periplaneta to acids with a chain length up to six carbons and to amines (Altner et al, 1977;Altner and Prillinger, 1980). In addition, most receptor cells in the dw-wp sensilla coeloconica from Bombyx responded best to acids and aldehydes (Pophof, 1997). At present, we do not understand the physiological function of the structural differences between the sw-wp and dw-wp sensilla using, respectively, the pore tubule system and spoke channel system of stimulus entry (Hunger and Steinbrecht, 1998;Steinbrecht, 1997).…”

“…Such close contacts between receptor cells have also been reported in thin sections of the olfactory dw sensilla coeloconica of Bombyx (Hunger and Steinbrecht, 1998), in the single-walled peglike sensillum in the coleopteran Ceutorhynchus (Isidoro and Solinas, 1992), in gustatory sensilla (Isidoro et al, 1994;Moulins and Noirot, 1972) and between thermo/hygroreceptor cells of Bombyx (Steinbrecht, 1989). Physiological cross-talk such as peripheral inhibitory or excitatory interactions, mediated possibly through gap junctions, has been recorded in olfactory dw sensilla coeloconica in Bombyx (Pophof, 1997) and in sensilla placodea of the beetle Popillia (Nikonov and Leal, 2002), in gustatory of low amplitude responded to isobutylamine. Fig.…”

Antennal sensilla in five Psychodini moth flies (Diptera: Psychodidae: Psychodinae) pollinators ofArumspp. (Araceae)

“…Th e sensilla coeloconica of the Psychodini are similar to those of the Lepidoptera in which the two types are present (Faucheux 1999). Th ese sensilla are olfactory receptors in Lepidoptera (Pophof 1997). In Apis mellifi ca, some sensilla coeloconica respond only to carbon dioxide while others react to temperature and humidity (Lacher 1964).…”

Electrophysiological studies of olfaction in the whip spider Phrynus parvulus (Arachnida, Amblypygi)

“…In a few cases, an accompanying hyperpolarization of the neuronal membrane has also been demonstrated (Den Otter et al, 1980;Pophof, 1997). If a sufficient number of neurons responded in this way they would be expected to produce an increase in the potential recorded by an electroantennogram.…”