The Otis Lab has three, state-of-the-art, multiphoton microscopes. The first is a Bruker system that allows for imaging in awake, behaving mice. This microscope is equipped with lasers that allow simultaneous calcium imaging and optogenetics or uncaring, with with a spatial light modulator that allows single-cell stimulation or inhibition within each field of view. In addition, this microscope has been equipped with LEDs for full field optogenetics during imaging. The second system is a custom-built two-photon microscope that can be used for both for imaging in vivo or ex vivo, and is awaiting a motivated postdoc who wishes to use this system. The third system is attached to a state-of-the-art patch-clamp electrophysiology rig, and can also be used for simultaneous optogenetics or uncaging experimentation. While the Otis Lab is currently renovating and fine-tuning this microscope, the hope is to use it for collaborative experiments throughout the Department of Neuroscience at MUSC.
Dr. Otis was among the first ever to record the activity of axons deep in the brain, and also to optogenetically manipulate these axons while recording from downstream neurons . The lab plans to continue such approaches to better understand the neural circuit mechanisms of reward seeking and drug addiction. For an example of two-photon imaging experiments, check out Otis et al., 2017 Nature and Otis et al., 2019 Neuron.
The Otis Lab has a state-of-the art patch-clamp electrophysiology system, equipped with components that allow optogenetics or two-photon imaging ex vivo. This system can be used to study the synaptic architecture of neural circuits. In addition, we use patch-clamp electrophysiology to study how neural circuits change in response to experience. Such plasticity is a major component of neuropsychiatric diseases, and therefore is a major focus of the lab. For examples of patch-clamp electrophysiology experiments, check out Otis et al., 2017 Neurospychopharmacology or Otis et al., 2018 Frontiers in Behavioral Neuroscience.
The Otis lab uses a combination of viral strategies to identify the precise connectivity of neural circuits. These strategies include, but are not limited to, cre-driven rabies tracing, retrograde toxin labeling, anterograde tracing, as well as a combination of the above techniques that allow us to identify the precise architecture of neural circuits. For an example of such strategies, see the extended figures from Otis et al., 2017 Nature.
In addition to using optogenetics during two-photon imaging and patch-clamp electrophysiology experiments, we using optogenetics to determine the neural mechanisms that underly the behaviors of freely moving animals. As such, we couple optogenetics with a variety of custom-designed behavioral assays, such as Pavlovian conditioning, operant behaviors, conditioned place preference, and more. For examples of these behaviors, check out Otis et al., 2017 Nature or Otis et al., 2018 Frontiers in Behavioral Neuroscience.