The Department of Biomedicine

BBB seminar: Bente Gunnveig Berg

Odor coding strategies: Findings from a small insect brain

Main content

Bente Gunnveig Berg
Chemosensory Laboratory, Department of Psychology, Norwegian University of Science and Technology, Trondheim

Olfaction is the least understood and the most underestimated sensory system. One main reason for the lack of knowledge is related to the nature of the odor cues. Odor signals cannot be characterized according to a single property such as wavelength or frequency. These stimuli, which consist mainly of organic molecules produced by life itself, represent countless amounts of molecular structures possessing different physiochemical properties.

Smell constitutes our phylogenetically oldest sensory system. Due to the strong conservation of the olfactory system through evolutionary development, various model organisms have been used for exploring how a neural network solves the problem of detecting and processing odor input from the external environment. Several striking similarities exist in the olfactory pathways of phylogenetically distant organisms.

In our research, we study how odor input is encoded in a functional neural network preserved by nature itself during a period of more than 100 million years – i.e., the olfactory pathways of a noctuid moth. In fact, when a male moth seeks for food or a potential mate, it can detect the relevant odorants at a distance of more than one kilometer. In addition to its well-developed sense of smell, the moth is a favorable research model due to its relatively easily accessible nervous system.

We utilize different experimental approaches for exploring how biologically relevant odor signals are processed at various synaptic levels of the olfactory pathway. By combining the intracellular recording/staining technique in living insects with confocal microscopy, we obtain precise data about the basic brain elements, i.e., the neurons. Calcium imaging measurements, on the other hand, provide corresponding data from neuron populations. In the presentation, I will explain some examples on coding mechanisms in the moth olfactory system and how these correspond to chemosensory principles in general.

Chairperson: Boleslaw Srebro, Department of Biomedicine