NEC Friday morning Seminar
Speaker: Jiaxin Zhou
Advisor: Dominique Durand
Location: Sears 439
Abstract: Sharp-wave ripples (SPW-Rs) are brief, highly synchronized network events that occur during sleep and rest, and are thought to support memory consolidation. However, it is unknown how these events propagate through neural tissue and whether they can directly alter synaptic plasticity. To address this, we examined SPW-R-like activity in hippocampal slices using a physical cut to disrupt synaptic connections while preserving the surrounding tissue. We found that SPW-R-like signals could propagate across the cut, suggesting communication through electric fields rather than synapses. Functionally, this activity suppressed long-term potentiation (LTP), a cellular mechanism of memory, and this suppression was observed at multiple locations within CA1, indicating a global effect. Finally, we tested whether this suppression could be controlled using direct current stimulation (DCS) and found that anodal, but not cathodal, stimulation protected LTP from SPW-R–induced suppression. Together, these results show that sleep-related network activity can weaken memory-related plasticity through ephaptic mechanisms and that weak electrical stimulation can be used to counteract this effect.