Poster abstracts
Poster number 78 submitted by Kaarthik Abhinav Balakrishnan
Uncovering computational principles for thermoregulation in ectotherms through behavioral characterization in larval zebrafish
Kaarthik Balakrishnan (Biophysics Graduate Program, The Ohio State University), Martin Haesemeyer (Assistant Professor, Department of Neuroscience, The Ohio State University)
Abstract:
Avoidance of extreme temperatures is critical for all living organisms. Endotherms use internal and behavioral mechanisms to regulate their body temperature. Ectotherms on the other hand are in equilibrium with their surroundings and rely on behavioral mechanisms to thermoregulate by navigating thermal profiles in the environment. Ectotherms are therefore ideally suited to provide insight into the relation between thermosensory input and behavioral output. Larval zebrafish are excellent model organisms to study mechanisms of behavioral thermoregulation because they are ectotherms with an archetypical vertebrate brain. Furthermore, their behavioral repertoire is highly tractable, consisting primarily of modulating the direction of motion and swim speeds. Our previous work uncovered how larval zebrafish avoid hot temperatures by raising their swim speeds in warmer water and performing evasive turns in the presence of increasing temperatures. However, it is critical to understand behavioral responses to both hot and cold temperatures in order to develop a model that describes thermoregulation of an organism, and to specify a notion of preferred temperature regime for the organism. Hence, we will characterize the behavior of freely swimming larval zebrafish in cold temperatures by tracking their movement in a chamber with temperature gradients. We will develop a model of thermoregulation by relating absolute temperatures and changes in temperature to swim speeds and turns, in a range of hot and cold temperatures. This model will reveal the underlying computational principles which transform external temperature input to behavioral output and its relation to the position of the organism in temperature space. Subsequently, this will inform future investigations of possible neural circuits giving rise to thermoregulatory behavior and the encoding of temperature preference in the brain.
References:
1. Haesemeyer M, Robson DN, Li JM, Schier AF, Engert F. A Brain-wide Circuit Model of Heat-Evoked Swimming Behavior in Larval Zebrafish. Neuron. 2018;98(4):817-831.e6. doi:10.1016/j.neuron.2018.04.013
2. Luo L, Gershow M, Rosenzweig M, et al. Navigational decision making in Drosophila thermotaxis. J Neurosci. 2010;30(12):4261-4272. doi:10.1523/JNEUROSCI.4090-09.2010
Keywords: Thermoregulation, Larval zebrafish, Computational modeling