Current Projects

We have found that thalamocortical brain state changes very rapidly, on the time scale of 10s of milliseconds or faster. We are currently searching for the neural pathways that could mediate these rapid shifts in behavioral attention, engagement, and brain state.

About half of the activity in the cortex and thalamus is related to brain state!  This activity strongly influences the ability to detect or discriminate a stimulus, to choose to act on the stimulus, and to make an appropriate response. Being in the optimal state for performance requires tight control of brain state. We are examining computational and behavioral mechanisms to determine how state influences performance.

By performing whole cell recordings in awake behaving animals, we can determine the synaptic mechanisms underlying neural and network function.  These recordings provide critical information on how excitatory and inhibitory neurons interact with the intrinsic membrane properties of cortical and thalamic cells to generate neural network dynamics of behavior.

Cholinergic and noradrenergic systems are critically involved in controlling the state of activity in the mammalian forebrain. We are examining the activity of these systems through 2-photon microscopy using a Thorlabs mesoscope and revealing how they may be involved in complex decision making and behaviora.

We are interested in the mechanisms by which some information can be ignored, while other enhanced, depending on experience or context. We train animals to ignore auditory information while paying attention to what they are seeing, for example. The animals may then switch, in a different context, to ignore vision and pay attention to audition. How is this achieved?  We hope to reveal the neural circuit and dynamics.

Contextually dependent behavior is pervasive throughout life.  We are training animals to switch attention from one sensory modality to another when given a cue. How is this cognitive and behavioral flexibility achieved? We are on the hunt for the neural pathways that may mediate this top-down cognitive control.

Thalamocortical systems generate state dependent activities, particularly different rhythms such as delta, alpha, and gamma waves. We are determining the precise cellular and network mechanisms of these rhythms and how they are controlled to appear at particular states of the brain and behavior.

The brain consists of a massively interconnected network of oscillators (neurons). Through an interaction of their intrinsic membrane properties and network dynamics, different circuits generate different rhythms (e.g. alpha, delta, gamma) in a state-dependent manner. We are revealing the cellular and network mechanisms of these rhythms and their modulation.

How does the nervous system select a relevant portion of the sensory world and stay locked onto it? We are examining the mechanisms by which animals are able to attend to particular stimuli in an optimal fashion, so that their behavior is well-tuned for the situation. These mechanisms involve both rapidly acting neural pathways using ionotropiceurotransmitters, as well as more long lasting neuromodulatory systems, which use g-protein mediated second messenger systems.

We have found that activation of the vagal nerve results in strong activation of thalamocortical networks and neuromodulatory systems. We are interested in examining the mechanisms of this brain-body interaction and the neural basis of interoception.

We are interested in examining how psychedelics modulate emotional pathways.

We are optimizing an introductory undergraduate course "Happiness: a Neuroscience and Psychology Perspective" (www.HappyNeurons.org) with the aim of making this course completely free to instructors throughout the world.