Reconstruction and Registration of three Bilateral Protocerebral Neurons in the Standard Brain Atlas of the Moth Heliothis virescens

Abstract

Insect behaviour is tightly connected to their ability to detect important sensory information from their environment. The tobacco moth Heliothis virescens moth follows airborne stimuli to acquire partners, food and suitable host plants for oviposition, and it is able to detect sounds allowing them to escape predation by bats. Understanding the underlying biological mechanisms behind its behavioural choices may be of importance in future methods for harmless biological control. In this present study, neurons of three bilateral protocerebral neurons in the moth H. virescens were chosen based on their electrophysiological responses and successful staining. The neurons were reconstructed using the manual labelling software Slicer, and registered into the standard brain atlas (SBA) using landmark registering in Amira. The neuron N1 which responded to an odorant (linalool) and the neuron N2 which responded to a sound stimulus (keychain) were both suggested to participate in reciprocal inhibition. This was due to their projection in corresponding areas in the contralateral hemisphere. N1 had its input in the left and output in the right LAL, and N2 descended from the VLP through the SOG towards the thoracic ganglion. Contrast enhancement between the sides may be important for localising a sound or odor in space. The neuron N3 innervated one glomerulus in each hemisphere before branching into the ventral protocerebrum, the right eye lobe and an area below the central body. This neuron was found to respond consistently to the major pheromone component and to novel stimuli of a sound and a light stimulus. This novelty detection may be important for focusing attention, and detecting important biologically relevant stimuli from the background noise in the environment.