TY - JOUR TI - Kv1.1 contributes to a rapid homeostatic plasticity of intrinsic excitability in CA1 pyramidal neurons in vivo AU - Morgan, Peter James AU - Bourboulou, Romain AU - Filippi, Caroline AU - Koenig-Gambini, Julie AU - Epsztein, Jérôme A2 - Slutsky, Inna A2 - Marder, Eve A2 - Remy, Stefan VL - 8 PY - 2019 DA - 2019/11/27 SP - e49915 C1 - eLife 2019;8:e49915 DO - 10.7554/eLife.49915 UR - https://doi.org/10.7554/eLife.49915 AB - In area CA1 of the hippocampus, the selection of place cells to represent a new environment is biased towards neurons with higher excitability. However, different environments are represented by orthogonal cell ensembles, suggesting that regulatory mechanisms exist. Activity-dependent plasticity of intrinsic excitability, as observed in vitro, is an attractive candidate. Here, using whole-cell patch-clamp recordings of CA1 pyramidal neurons in anesthetized rats, we have examined how inducing theta-bursts of action potentials affects their intrinsic excitability over time. We observed a long-lasting, homeostatic depression of intrinsic excitability which commenced within minutes, and, in contrast to in vitro observations, was not mediated by dendritic Ih. Instead, it was attenuated by the Kv1.1 channel blocker dendrotoxin K, suggesting an axonal origin. Analysis of place cells’ out-of-field firing in mice navigating in virtual reality further revealed an experience-dependent reduction consistent with decreased excitability. We propose that this mechanism could reduce memory interference. KW - hippocampus KW - CA1 pyramidal cells KW - intrinsic excitability KW - long-term plasticity KW - memory KW - in vivo patch-clamp JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -