Large-scale Optical Recording

PROJECT SUMMARY ? Project 3.

Large-scale Optical Recording Humans have both centralized and highly distributed nervous systems (e.g., brain and myenteric plexus) that are increasingly appreciated to have important interactions.

The nature of those interactions, and especially the degree to which such centralized and distributed nervous systems work together is poorly understood.

The proposed work will take advantage of a recently introduced model organism, the marine gastropod Berghia, to begin an exploration of this challenging topic.

Berghia has an embodied nervous system organization, consisting of a centralized brain that works with a diffusely distributed peripheral neural plexus. Project 3 will use large scale imaging to explore several features of such embodied processing. A notable feature of this U19 is its investment in generating the first transgenic mollusc for neuroscience.

Starting with a backbone of expertise in large scale imaging of neural activity with fast voltage sensitive absorbance dyes, this Project will also employ 1- and 2-photon fluorescence activity imaging, first with dyes and then with GCaMP6f Berghia strains.

Additional strains with light-activated channels will enable optogenetics, making possible all-optical electrophysiology in a system employing embodied neural processing. There are four specific aims.

Aim 1 will test the hypothesis that Berghia uses two motor control schemes for how it uses its oral tentacles: a traditional one in which the CNS directly drives all aspects of behavior, and an ?embodied? control scheme where the CNS cedes responsibility to a highly distributed peripheral neural plexus for certain behaviors.

This Aim will further test whether the animal can switch back-and-forth between these two tentacle motor control schemes, depending on the circumstances of the moment. Aims 2-4 are focused on issues related to sensory processing. Aim 2 will explore how somatosensory information is represented in Berghia?s nervous system.

Aim 3 will do the same for odor processing, and Aim 4 will assess the degree to which cross-modal sensory interactions and modulation of sensory processing play important roles.

Throughout the study, Project 3 will interact extensively with the other 4 Projects of this U19, united by the common goal of revealing general principles and mechanisms of embodied processing as a mode of nervous system function.