Daniel Wagenaar

The Wagenaar Lab studies the neuronal basis of sensory processing and sensory-guided behavior, with a specific focus on crossmodal sensory integration in the leech and on functional and anatomical circuit mapping. The relatively simple nervous system of the European medicinal leech is perfectly suited to develop insights about how the activity of all the cells in a nervous system together produce individual behaviors from overlapping functional networks, a phenomenon that—at a much larger scale and undoubtedly with many complexities added—is also crucial to human brain function.

In the leech, we can:

• Use voltage-sensitive dyes (VSDs) to record simultaneously from the vast majority of neurons in a functional unit of the nervous system during production of several behaviors (including swimming, crawling, and escape responses);
• Use serial blockface scanning electron microscopy (SBEM) to determine connectivity between the neurons in this functional unit;
• Combine these imaging modalities to gain insight into the relationship between structural elements such as circuit motifs and the behavioral functionality of neuronal networks.

Because the neuronal topography within the leech nervous system is well preserved across animals, it is possible to reliably localize specifically identified neurons across multiple animals and test hypotheses generated by the VSD and SBEM experiments using detailed electrophysiology.

In addition to leading his research lab, Dr. Wagenaar also directs the Neurotechnology Center, a resource for the Caltech neuroscience community aimed at collaborative development of novel technologies as well as adaptation of existing technologies for new applications in the realms of microscopy, electrophysiology, and more.