@article{8740,
  abstract     = {In vitro work revealed that excitatory synaptic inputs to hippocampal inhibitory interneurons could undergo Hebbian, associative, or non-associative plasticity. Both behavioral and learning-dependent reorganization of these connections has also been demonstrated by measuring spike transmission probabilities in pyramidal cell-interneuron spike cross-correlations that indicate monosynaptic connections. Here we investigated the activity-dependent modification of these connections during exploratory behavior in rats by optogenetically inhibiting pyramidal cell and interneuron subpopulations. Light application and associated firing alteration of pyramidal and interneuron populations led to lasting changes in pyramidal-interneuron connection weights as indicated by spike transmission changes. Spike transmission alterations were predicted by the light-mediated changes in the number of pre- and postsynaptic spike pairing events and by firing rate changes of interneurons but not pyramidal cells. This work demonstrates the presence of activity-dependent associative and non-associative reorganization of pyramidal-interneuron connections triggered by the optogenetic modification of the firing rate and spike synchrony of cells.},
  author       = {Gridchyn, Igor and Schönenberger, Philipp and O'Neill, Joseph and Csicsvari, Jozsef L},
  issn         = {2050084X},
  journal      = {eLife},
  publisher    = {eLife Sciences Publications},
  title        = {{Optogenetic inhibition-mediated activity-dependent modification of CA1 pyramidal-interneuron connections during behavior}},
  doi          = {10.7554/eLife.61106},
  volume       = {9},
  year         = {2020},
}

@article{5914,
  abstract     = {With the advent of optogenetics, it became possible to change the activity of a targeted population of neurons in a temporally controlled manner. To combine the advantages of 60-channel in vivo tetrode recording and laser-based optogenetics, we have developed a closed-loop recording system that allows for the actual electrophysiological signal to be used as a trigger for the laser light mediating the optogenetic intervention. We have optimized the weight, size, and shape of the corresponding implant to make it compatible with the size, force, and movements of a behaving mouse, and we have shown that the system can efficiently block sharp wave ripple (SWR) events using those events themselves as a trigger. To demonstrate the full potential of the optogenetic recording system we present a pilot study addressing the contribution of SWR events to learning in a complex behavioral task.},
  author       = {Rangel Guerrero, Dámaris K and Donnett, James G. and Csicsvari, Jozsef L and Kovács, Krisztián},
  journal      = {eNeuro},
  number       = {4},
  publisher    = {Society of Neuroscience},
  title        = {{Tetrode recording from the hippocampus of behaving mice coupled with four-point-irradiation closed-loop optogenetics: A technique to study the contribution of Hippocampal SWR events to learning}},
  doi          = {10.1523/ENEURO.0087-18.2018},
  volume       = {5},
  year         = {2018},
}

@article{1334,
  abstract     = {Hippocampal neurons encode a cognitive map of space. These maps are thought to be updated during learning and in response to changes in the environment through activity-dependent synaptic plasticity. Here we examine how changes in activity influence spatial coding in rats using halorhodopsin-mediated, spatially selective optogenetic silencing. Halorhoposin stimulation leads to light-induced suppression in many place cells and interneurons; some place cells increase their firing through disinhibition, whereas some show no effect. We find that place fields of the unaffected subpopulation remain stable. On the other hand, place fields of suppressed place cells were unstable, showing remapping across sessions before and after optogenetic inhibition. Disinhibited place cells had stable maps but sustained an elevated firing rate. These findings suggest that place representation in the hippocampus is constantly governed by activity-dependent processes, and that disinhibition may provide a mechanism for rate remapping.},
  author       = {Schönenberger, Philipp and O'Neill, Joseph and Csicsvari, Jozsef L},
  journal      = {Nature Communications},
  publisher    = {Nature Publishing Group},
  title        = {{Activity dependent plasticity of hippocampal place maps}},
  doi          = {10.1038/ncomms11824},
  volume       = {7},
  year         = {2016},
}