Date of Award
Union College Only
Bachelor of Science
neurons, fields, receptive, target, dimensional
Dragonflies have a small group of neurons in the central nervous system that control prey-capture behavior. These neurons have been previously identified, and their receptive fields mapped in two-dimensions. They send information about prey movement from the brain to direct flight response. Previous research has used two dimensional digital displays to stimulate these neurons and map receptive fields. It remains to be seen how these neurons respond to a three-dimensional target in a natural setting. In our study we reconstruct the receptive fields of target-selective neurons in three-dimensions using small white beads to simulate prey movement. Electrophysiological recordings were taken using a suction electrode, which allowed us to record from multiple cells at once in the ventral nerve cord. Beads of varied sizes were moved in front of the dragonfly to stimulate the target selective neurons. Neuronal spikes were grouped based on spike characteristics into specific units, or neurons. The bead movement was modeled in three dimensions using high-speed video capture, and then correlated with individual spikes. We were able to derive information about positional and directional preferences of target-selective neurons. Based on this information, three-dimensional receptive fields were constructed for neurons including the directional preference of these neurons. Our data shows that the receptive fields of these neurons are more broad than previously identified. Finally, we found that the TSDNs either preferred targets with a larger visual angle, or were responsive to targets over a range of visual angles.
Shulman, David S., "Three-dimensional reconstruction of prey-capture-neuron receptive fields in dragonflies" (2008). Honors Theses. 1535.