SPECIAL QUANTITATIVE BIOLOGY SEMINAR
Advances in Imaging Invertebrate Neural Networks with Fast Voltage Sensitive Dyes
Progress in understanding the neural basis of behavior requires a detailed knowledge of the underlying neural networks. A powerful tool for deciphering neural networks is large-scale imaging with fast voltage sensitive dyes. Our approach uses a three step procedure, which we are currently applying to rhythmic motor networks in the marine mollusks Aplysia and Tritonia. In the first step, nerve-evoked rhythmic motor programs are imaged using a 464-element photodiode array. In the second step, we use independent component analysis to process the raw data into single neuron action potential traces. This procedure also returns maps of the ganglion locations of all resolved neurons. By concatenating files collected at different times during a single preparation, the firing behavior of ~ 100 individual neurons can be followed across separate acquisition files spanning different experimental treatments. In the third step, we apply statistical clustering methods to reveal the significantly related ensembles of neurons present in the recorded population. This approach represents a powerful new tool for studying the neural basis of behavior. The talk will demonstrate its use to: 1) locate new neurons of interest; 2) characterize and map the different neuronal ensembles comprising a network; 3) identify and study neurons with multifunctional roles in behavior; 4) track neuronal and network changes over time with learning.