Brian H. Smith
Neuroethology of Sensory Processing
My laboratory focuses on how animals learn relationships among stimuli in their environment, and, in particular, on how those stimuli predict the occurrence important events such as food, predators or mates. Our analyses begin with detailed behavioral studies designed to investigate what animals know and how they come to know it. We integrate mechanisms that are revealed in these investigations into a larger ecological framework in order to understand how animals solve problems under natural conditions. Furthermore, we study learning and memory under controlled laboratory conditions in order to investigate how neural and molecular mechanisms encode information in the peripheral and central CNS. Finally, we collaborate with mathematicians to develop computational models of neural networks in order to integrate information across molecular, neural and behavioral levels and help to generate new testable, hypotheses.
Specifically, we focus on the integration of visual and olfactory information in different situations using insects - primarily the honeybee - as a model. Honeybees quickly learn about the ephemeral association of floral resources - nectar and pollen - with cues (color, shape, odor, texture) flowers produce to attract pollinators. Furthermore, navigation through complex environments as well as social interactions in honeybees are similarly governed by a combination of innate predispositions and the ability to modify those responses through experience.
Particularly in regard to olfaction, it is interesting that neural mechanisms for olfactory processing in the peripheral and first few synapses of the central nervous systems of insects such as the honeybee are similar to those of vertebrates, and this similarity probably arose independently rather than being derived from a common ancestor. The likely convergence on the same solution to early olfactory coding in these different evolutionary lineages may indicate that there is one, or perhaps only a few, fundamental neural solutions to olfactory processing. For this reason, a comparative approach may stand to reveal important principles of sensory coding and learning.
Selected Recent Publications
Latshaw JS, Smith BH (2005) Heritable variation in learning performance affects foraging preferences in the honey bee (Apis mellifera) Behavioral Ecology Sociobiology 58: 200-207.
Wright GA, Lutmerding A, Dudareva N, Smith BH. (2005) Intensity and the ratios of compounds in the scent of snapdragon flowers affect scent discrimination by honey bees (Apis mellifera) J. Comparative Physiology 191: 105-114.
Shafir S, Menda G, Smith BH (2005) Caste-specific difference in risk sensitivity in honeybees. Animal Behavior. 69: 859-868.
Farooqui T, Vaessin H, Smith BH (2004) Octopamine receptors in the honeybee (Apis mellifera) brain and their disruption by RNA-mediated interference. Journal of Insect Physiology. 50: 701-713.
Borisyuk A, Smith BH (2004) Odor interactions and learning in a model of the insect antennal lobe. Neurocomputing 58-60: 1041-1047.
Daly KC, Christensen TA, Lei H, Smith BH, Hildebrand JG (2004) Learning modulates the ensemble representations for odors in primary olfactory networks Proceedings National Academy Science (USA). 101: 10476-10481.
Daly KS, Wright GA, Smith BH (2004) Molecular features of odorants systematically influence slow temporal responses across clusters of coordinated antennal lobe units in the moth Manduca sexta. J. Neurophysiology. 92, 236-254.
Wright GA, Smith BH. (2004) Different thresholds for detection and discrimination of odors in the honeybee (Apis mellifera) Chemical Senses 29: 127-135.
Wright GA, Smith BH. (2004) Variation in complex olfactory stimuli and its influence on odour recognition. Proceedings of the Royal Society London B 271: 147-152.
Farooqui T, Robinson K, Vaessin H, Smith BH (2003) Modulation of early olfactory processing by an identified octopaminergic reinforcement pathway in the honeybee. J. Neuroscience. 23: 5370-5380.
Review
Smith, BH, Wright GA, Daly KS (2006) Learning-based recognition and discrimination of floral odors. In The Biology and Chemistry of Floral Scents (N Dudareva, E Pichersky, eds). CRC Press.