ISTI-TALK: How Astrocytic Potassium Buffering Shapes Neural Synchronization: A Microcircuit Modelling Approach
- Day - Time: 10 June 2026, h.12:00
- Place: Area della Ricerca CNR di Pisa - Room: C-29
Speakers
Referent
Abstract
Neural synchronization is fundamental to brain function, underpinning learning, memory consolidation, and cognition through coordinated oscillatory activity in hippocampal circuits. When synchronization becomes excessive, however, it
leads to pathological conditions such as epilepsy. The hippocampus, situated within the temporal lobe, represents the brain region with the highest propensity for epileptiform activity. Within the hippocampus, extracellular potassium dynamics are central to non-synaptic epileptiform activity, and astrocytic potassium buffering has emerged as a key regulator of network excitability. Yet the specific contributions of astrocytic gap-junction coupling and spatial buffering to neuronal synchronization across spatial scales remain poorly understood. To address this gap, we developed a biophysical microcircuit model comprising two astrocyte-neuron modules that interact exclusively through shared extra-cellular potassium dynamics. Our results show that astrocytes prevent pathological states, including ictal activity and depolarization block, by stabilizing extracellular potassium. Furthermore, gap-junction coupling strength critically regulates inter-module phase synchronization: stronger coupling promotes synchrony under physiological conditions, whereas impaired astrocytic function drives hypersynchronization at elevated potassium levels. These findings suggest astrocytic connexins as a relevant therapeutic target in epilepsy and disorders of aberrant neural synchronization.