The Otis Lab has two, 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 3 lasers, with additional laser lines for single cell optogenetics via spatial light modulation. 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. For example, we can use this system to perform two-photon uncaging experiments during patch-clamp electrophysiology.
Dr. Otis was among the first ever to record the activity of axons deep in the brain, and also to optogenetically manipulate the activity of axons while imaging from downstream neurons (new paper demonstrating these techniques coming soon). 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.
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.
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.