Cell Type and Circuit Mechanisms of Non-Invasive Brain Stimulation by Sensory Entrainment Patterned sensory stimulation (PSS) is a non-invasive technique for manipulating brain activity and states, typically employing periodic light flicker or auditory tones presented at regular intervals.
Project Summary Electrical stimulation of deep brain structures is an essential tool for the causal investigation of neural systems that regulate learning and decision making. Deep brain electrical stimulation is also a valuable tool for treating neurological disorders such as Parkinson's disease and tremor, and recent data suggests that electrical brain stimulation may effectively treat epilepsy and severe depression.
Non-invasive neuromodulation approaches have been developed to enable the modulation of neural tissue without necessitating invasive surgical procedures. Low-intensity transcranial focused ultrasound (tFUS) neuromodulation has proven its efficacy and precision in modulating the brain, from the neuron to circuit level. However, there is an urgent unmet need to elucidate the in vivo neuronal and inter-neuronal effects of the tFUS neuromodulation, thus advancing the translational application of tFUS neuromodulation on humans.
Measurements of cortical field potentials are widely used throughout basic and clinical neuroscience, including in electroencephalography (EEG), electrocorticography (ECoG) and local field potential (LFP) recordings. However, the neural origins of field potentials remain poorly understood, due to a lack of techniques for dissecting how different classes of cells contribute to field potential signals.
Unveiling mechanisms of neural stimulation technologies is an important goal of the Brain Initiative (RFA-NS-20-006). Transcranial electric stimulation (TES) is a non-invasive neuromodulation technique to provide wide-range effects on seizure control, behaviors, and cognition by generating weak electric fields in the brain. It is still an open question of how these weak electric fields can interact effectively with neural activity, and the mechanism of action of TES is still unknown.
Neurostimulation, including invasive methods like deep brain stimulation (DBS), is an increasingly important approach to treating mental illness. It offers the possibility of directly targeting the circuit dysfunctions that produce mental disorders. The clinical use of brain stimulation, and DBS in particular, has been limited by a lack of mechanistic understanding. We do not know why/how stimulating a specific region or pathway leads to symptom improvement. This limits our ability to correctly “dose” stimulation, or to verify biological target engagement.
This proposal responds to BRAIN Initiative RFA-NS-20-006 and aims to elucidate the neural and biophysical mechanisms of noninvasive focused ultrasound (FUS) neuromodulation.
The cerebellum has been overlooked for its potential for neuromodulation for decades. Traditionally thought of as critical for motor coordination, anatomical, clinical and imaging evidence now indicate that the cerebellum also has central roles in cognition and emotion, and that cerebellar dysfunction impacts these functions. Consistent with these findings of cerebellar involvement in motor and non-motor functions, projections from the cerebellar nuclei (CN) target, via the thalamus, both motor and non-motor areas of the cortex and the basal ganglia.
Summary Most perceptual, cognitive, and motor functions rely on neuronal activity distributed across multiple networks, often located in different brain areas. In many systems, including the visual system, signaling between areas is bidirectional: lower areas communicate with higher ones via feedforward connections, and higher areas signal to lower areas via feedback. Feedforward pathways are thought to underlie the increasingly sophisticated receptive fields as one ascends the visual hierarchy. The role of feedback signaling in visual processing, in contrast, is poorly understood.
Summary This proposal will investigate the neural dynamics underlying three-dimensional foraging behavior, with three overarching goals. The first is to evaluate the neural computations of foraging in dynamic environments in naturalistic settings. The second is to compare the algorithmic behavioral computations and their neural substrates under naturalistic versus traditional laboratory settings. Most neuroscience studies assume that laboratory behavior has real-world implications, so any differences we observe would have remarkable consequences for the future of neuroscience.
