In our experimental study, we combined paired patch-clamp recordings and two-photon Ca2+ imaging to quantify inhibition exerted by individual GABAergic contacts on hippocampal pyramidal cell dendrites. We observed that Ca2+ transients from back-propagating action potentials were significantly reduced during simultaneous activation of individual nearby GABAergic synapses. To simulate dendritic Ca2+ inhibition by individual GABAergic synapses, we employed a multi-compartmental CA1 pyramidal cell model with detailed morphology, voltage-gated channel distributions, and calcium dynamics, based with modifications on the model of Poirazi et al., 2003, modelDB accession # 20212.
Model Type: Neuron or other electrically excitable cell
Region(s) or Organism(s): Hippocampus
Cell Type(s): Hippocampus CA1 pyramidal GLU cell
Currents: I Calcium; I Sodium; I Potassium; I h
Transmitters: Gaba
Model Concept(s): Action Potentials; Dendritic Action Potentials; Active Dendrites; Calcium dynamics
Simulation Environment: NEURON
Implementer(s): Muellner, Fiona E [fiona.muellner at gmail.com]
References:
Müllner FE, Wierenga CJ, Bonhoeffer T. (2015). Precision of Inhibition: Dendritic Inhibition by Individual GABAergic Synapses on Hippocampal Pyramidal Cells Is Confined in Space and Time. Neuron. 87 [PubMed]