Rhythmic neural activity in the gamma range (30-90 Hz) is modulated during various aspects of cognitive function and has been shown to be disrupted in several neurological conditions, including Alzheimer's disease (AD). Impaired gamma oscillations have also been reported in several AD mouse models. We found abnormal gamma oscillations in the hippocampus of young AD model mice months before the onset of Aβ accumulation and major cognitive impairment. It is well established that local network oscillations at specific frequencies can be induced in cortical areas using sensory stimuli. Recently, we applied this approach, which we term Gamma ENtrainment Using Sensory stimuli (GENUS), using a light programmed to flicker at 40 Hz to induce gamma oscillations in the visual cortex of AD model mice. We found a profound reduction in amyloid load in visual cortex after 1 hr of visual GENUS that appears to involve the concerted actions of many different cell types, including neurons and microglia to reduce the production and enhance clearance of Aβ, respectively. We present current work on applying GENUS through other sensory modalities, and examining how GENUS can be induced to affect multiple brain areas that are downstream from cortical sensory areas.
Gamma frequency entrainment using sensory stimuli confers neuroprotection across multiple brain regions
Thursday, March 15, 2018 - 12:00pm to 1:00pm
Neurological Institute Alumni Auditorium
Dr. Li-Huei Tsai
Massachusetts Institute of Technology