Clearing pigmented insect cuticle to investigate small insects' organs in situ using confocal laser-scanning microscopy (CLSM).

Various microscopic techniques allow investigating structures from submicron to millimeter range, however, this is only possible if the structures of interest are not covered by pigmented cuticle. Here, we present a protocol that combines clearing of pigmented cuticle while preserving both, hard and soft tissues. The resulting transparent cuticle allows confocal laser-scanning microscopy (CLSM), which yields high-resolution images of e.

Representation of thermal information in the antennal lobe of leaf-cutting ants.

Insects are equipped with various types of antennal sensilla, which house thermosensitive neurons adapted to receive different parameters of the thermal environment for a variety of temperature-guided behaviors. In the leaf-cutting ant Atta vollenweideri, the physiology and the morphology of the thermosensitive sensillum coeloconicum (Sc) has been thoroughly investigated. However, the central projections of its receptor neurons are unknown.

Detection of minute temperature transients by thermosensitive neurons in ants.

The antennae of leaf-cutting ants are equipped with sensilla coeloconica that house three receptor neurons, one of which is thermosensitive. Using convective heat (air at different temperatures), we investigated the physiological characteristics of the thermosensitive neuron associated with the sensilla coeloconica in the leaf-cutting ant Atta vollenweideri. The thermosensitive neuron very quickly responds to a drop in temperature with a brief phasic increase (50 ms) in spike rate and thus classifies as cold receptor (ambient temperature = 24°C).

The thermo-sensitive sensilla coeloconica of leaf-cutting ants (Atta vollenweideri).

Social insects show a variety of temperature-guided behaviors. Depending on whether heat reaches the sensillum via air movements (convective heat) or as radiant heat, specific adaptations of thermo-sensitive sensilla are expected. In the present study the morphology and the physiology of thermo-sensitive peg-in-pit sensilla (S.