Bimodal nonlinear dendrites in PV+ basket cells drive distinct memory-related oscillations
Alexandra Tzilivaki, Matthew Evan Larkum, Dietmar Schmitz
PV+ FSBCs are critical for modulating hippocampal oscillations, which are essential for memory and behavior. Our research uses biophysical modeling to propose a cellular, dendritic dependent mechanism: these interneurons can dynamically switch their firing patterns by engaging different dendritic integration modes. We predict that PV+ FSBCs can use their supralinear and sublinear dendrites to selectively influence brain rhythms without changes in synaptic input amount. Supralinear dendrites promote high-frequency os- cillations and decrease the circuit’s excitation/inhibition (E/I) balance. Conversely, sublinear dendrites enhance slow oscillatory power and increase the E/I balance. This bimodal dendritic strategy gives PV+ FSBCs an energy-efficient way to regulate oscillations. It suggests that the specific computations happening within the dendrites of these interneurons can critically shape memory-related brain rhythms. This offers an experimentally testable hypothesis about the subcellular mechanisms of rhythm generation in the hippocam- pus.
iScience. 4;28(11):113699 (2025)