029 | Gamma audiovisual stimulation promotes integration of granule cells born in the aging hippocampus

Cellular and Molecular Neurobiology

Author: Magalí Herrero | Email: mherrero@leloir.org.ar

Magalí Herrero , Matías Mugnaini , Sabrina Benas , Andrea Aguilar Arredondo , Agostina Miranda , Emilio Kropff , Alejandro F. Schinder , Mariela F. Trinchero

1° Neuronal Plasticity Laboratory, Leloir Institute (CONICET) – Buenos Aires – Argentina
2° Physiology and Algorithms of the Brain Laboratory, Leloir Institute (CONICET) – Buenos Aires – Argentina

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. However, the mechanisms that transduce light and sound stimulation (“flickering”) 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 hippocampus of 8-month-old mice. Gamma flickering enhanced the 40 Hz component in dentate gyrus oscillations and boosted circuit remodeling as shown by the accelerated growth of the dendrites and mature electrophysiological features 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.