Effects of Bimodal Olfactory and Mechanosensory Inputs in the Antennal Lobe of the Honeybee Apis mellifera

Animals often aggregate information from multiple different sensory modalities to accurately assess and react to a stimulus. It is often assumed that cross-modality integration mostly occurs at high-level processing centers, such as the mammalian cortex or insect mushroom bodies. However, we hypothesized that integration could occur relatively early in the sensory pathways. The insect antennal lobe is one such location, receiving direct inputs from the antennae via the antennal nerve. These inputs are highly multimodal, including olfactory, mechanosesnory, and gustatory information, all of which are relevant to foraging honeybees (Apis mellifera). Here we assess integration by recording electrophysiological spike data within the honeybee antennal lobe while exposing the bee to various combinations of wind speed and odor concentration. This paper accompanies another publication by Joseph Reed and Mainak Patel approaching the same question from a modelling perspective, where their model corroborates our data and vice versa. Together, we show that integration occurs within this early layer of processing, while also demonstrating the complex relationship of these two closely-linked stimuli. SIGNIFICANCEAccurate perception depends on the brains ability to combine information from multiple senses, commonly thought belonging to high level of information processing. Using the European honeybee, Apis mellifera, we show strong evidence that olfactory and mechanosensory signals interact at an early stage of neural processing, within the antennal lobe, producing stimulus representations closely-linked to the animals navigation and decision-making. By identifying a tractable model for early multisensory processing, this work offers broader insight into how animals construct reliable representations of their environment.