Disruption of hippocampal rhythms via optogenetic stimulation during the critical period for memory development impairs spatial cognition

Objective . Investigate whether the disruption of normal hippocampal rhythms via optogenetic stimulation medial septum (MS) during late postnatal development has enduring effects on allocentric memory rat pups. Methods Hippocampal theta oscillations were non-endogenously regulated in pups using blue light (465-nm) pan-neuronal activation MS from day (P)21–25 random sinewave frequencies ranging 0.5 to 110 Hz. Non-stimulated and yellow (590-nm) stimulated rats used as controls, local field potentials hippocampus recorded unilaterally stimulations. In early adulthood, spatial cognition was assessed active avoidance task. Rats perfused tissue containing harvested sectioned assess cell density. Power spectrum density both hippocampus; coherence, voltage correlation analysis between structures compare baseline disruptive stimulation. Results During development, non-selective tightly oscillations. Disruptive increased power but reduced coherence correlations; resulted impaired learning compared with controls. Impairment not attributed or loss. Conclusions. These results demonstrate that can be precisely weanling rats. A protocol critical period long-standing cognitive deficits is Significance activity such occurs life seizures, complex developing neural circuits relevant cognition. By mimicking MS-hippocampal entrainment an isolated fashion, it may possible pinpoint mechanisms through which ELS affect