Organization of the antennal lobes in the praying mantis (Tenodera aridifolia)

Abstract

Olfaction in insects plays pivotal roles in searching for food and/or for sexual partners. Although many studies have focused on the olfactory processes of nonpredatory insect species, little is known about those in predatory insects. Here, we investigated the anatomical features of the primary olfactory center (antennal lobes) in an insect predator whose visual system is well developed, the praying mantis Tenodera aridifolia. Both sexes of T. aridifolia were found to possess 54 glomeruli, and each glomerulus was identified based on its location and size. Moreover, we found a sexual dimorphism in three glomeruli (macroglomeruli) located at the entrance of the antennal nerves, which are 15 times bigger in males than their homologs in females. We additionally deduced the target glomeruli of olfactory sensory neurons housed in cognate types of sensilla by degenerating the sensory afferents. The macroglomeruli received sensory inputs from grooved peg sensilla, which are present in a large number at the proximal part of the males' antennae. Furthermore, our findings suggest that glomeruli at the posteriodorsal part of the antennal lobes receive sensory information from putative hygro- and thermosensitive sensilla. The origins of projections connected to the protocerebrum are also discussed. J. Comp. Neurol. 525:1685-1706, 2017. © 2016 Wiley Periodicals, Inc.

Two types of sensory proliferation patterns underlie the formation of spatially tuned olfactory receptive fields in the cockroach Periplaneta americana

“…We could not stain OSNs in a single sensillum on the distal antenna because of the long distance between the sensillum and the antennal lobe. To reveal the topographic organization of OSN axon terminals in the macroglomerulus, we modified the procedures of antennal degeneration experiments performed in the antennae of the mantis (Carle, Watanabe, Yamawaki, & Yokohari, ) and the cockroach (Nishino et al, ). Using male cockroaches in the “early period” of the 10th instar ( N = 15), LI ( N = 17), and adult stages ( N = 21), we experimentally degenerated OSNs in the distal part of the antenna by amputating ~40 flagellomeres from the antennal tips (Figure a) and anterogradely stained the remaining afferents (Figure b).…”

Anatomical organization of the cerebrum of the praying mantis Hierodula membranacea

“…In H. membranacea , the AL has relatively large glomeruli, similar to those in the cockroach ( R. maderae ), although in a smaller number, probably due to the mantis’ strong reliance on visual input. In the Chinese mantis ( Tenodera aridifolia ), 54 glomeruli were identified in the AL (Carle et al., 2017), slightly less than the 61 glomeruli counted in H. membranacea . The glomeruli are connected through different AL tracts to higher brain areas for further processing of olfactory cues.…”

Aldehyde-specific responses of olfactory sensory neurons in the praying mantis

“…Although cockroaches are closely related to mantises, the behavioural role of the sensilla do not appear to be conserved between these groups. Olfactory sensilla in mantises have been morphologically classified 16 and organization of the primary olfactory centre (antennal lobe) in the mantis brain has been studied 40 . However, the pathway of olfactory information, such as the projection pattern of OSNs to the antennal lobe, has not been well studied.…”