Gamma audiovisual stimulation induces plasticity in granule cells born in the aging hippocampus

TRINCHERO MF; HERRERO M; MUGNAINI M; MIRANDA A; KROPFF E; SCHINDER AF

Congreso; Society for Neuroscience Annual Meeting; 2022

Non-invasive gamma audiovisual stimulation at 40 Hz can reduce levels of amyloid beta peptide and improve memory performance in several mouse models of Alzheimer’s disease. While light and sound stimulation (“flickering”) was shown to increase the gamma frequency component of hippocampal oscillations, the mechanisms that transduce these stimuli into cellular and circuit changes remain elusive. Because neurogenesis in the aging hippocampus is particularly sensitive to behavioral stimuli, the effects of gamma flickering might be revealed by analyzing its impact on developing new neurons. Using light and sound pulses, we studied the impact of 40 Hz stimuli on the development of neurons born in the dentate gyrus of 8-month-old mice. Gamma flickering enhanced the 40 Hz component in dentate gyrus oscillations and boosted circuit remodeling by neurogenesis, as shown by the accelerated growth of newly generated neurons. These results reveal that audiovisual stimuli awaken mechanisms that promote neuronal plasticity not only under pathological conditions, but also in the healthy aging brain.