Research Abstract:
Our research is focused on information processing in sensory systems, especially with regards to temporal coding – the encoding of sensory information into the precise timing of action potential activity and the decoding, or extraction, of that information by downstream neurons. Our research subjects are the weakly electric mormyrid fishes from Africa. These fish generate weak electric signals that they use to communicate with each other and to actively sense their environment. Their electric communication behavior and associated neural pathways are relatively simple compared to other vertebrates, which makes them particularly well suited to establishing direct links between the physiology of individual neurons or networks of neurons and quantitative characteristics of natural behaviors. In addition, these fish are extremely sensitive to temporal features in their electric signals. They are therefore an attractive model system for addressing basic questions about temporal coding by sensory systems, especially in the context of natural communication behavior. We study temporal coding at three different timescales: discrimination of sub-microsecond timing differences, temporal pattern recognition at the tens of milliseconds timescale, and finally, evolutionary diversification of electric communication behavior and its neural substrates. We address these issues using an integrative approach and a wide range of techniques, including electrophysiology, neuroanatomy and histology, imaging, computational modeling, behavioral observation and playback, and field work.
Selected Publications:
Carlson, BA, Kawasaki, M. Ambiguous encoding of stimuli by primary sensory afferents causes a lack of independence in the perception of multiple stimulus attributes. Journal of Neuroscience 2006 26: 9173-9183.
Carlson, BA, Kawasaki, M. Stimulus selectivity is enhanced by voltage-dependent conductances in combination-sensitive neurons. Journal of Neurophysiology 2006 96: 3362-3377.
Carlson, BA. A neuroethology of electrocommunication: senders, receivers, and everything in between. In: Ladich, F.; Collin, S. P.; Moller, P.; Kapoor, B.G., editors. Communication in Fishes. Enfield, NH: Science Publishers; 2006. p. 805-848.
Arnegard, ME, Carlson, BA. Electric organ discharge patterns during group hunting by a mormyrid fish. Proceedings of the Royal Society B: Biological Sciences 2005 272: 1305-1314.
Carlson, BA, Kawasaki, M. Nonlinear response properties of combination-sensitive electrosensory neurons in the midbrain of Gymnarchus niloticus. Journal of Neuroscience 2004 24: 8039-8048.
Last Updated: 07/01/2008 |