RT Journal Article SR Electronic T1 Slow GABA Transient and Receptor Desensitization Shape Synaptic Responses Evoked by Hippocampal Neurogliaform Cells JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 9898 OP 9909 DO 10.1523/JNEUROSCI.5883-09.2010 VO 30 IS 29 A1 Karayannis, Theofanis A1 Elfant, David A1 Huerta-Ocampo, Icnelia A1 Teki, Sundeep A1 Scott, Ricardo S. A1 Rusakov, Dmitri A. A1 Jones, Mathew V. A1 Capogna, Marco YR 2010 UL http://www.jneurosci.org/content/30/29/9898.abstract AB The kinetics of GABAergic synaptic currents can vary by an order of magnitude depending on the cell type. The neurogliaform cell (NGFC) has recently been identified as a key generator of slow GABAA receptor-mediated volume transmission in the isocortex. However, the mechanisms underlying slow GABAA receptor-mediated IPSCs and their use-dependent plasticity remain unknown. Here, we provide experimental and modeling data showing that hippocampal NGFCs generate an unusually prolonged (tens of milliseconds) but low-concentration (micromolar range) GABA transient, which is responsible for the slow response kinetics and which leads to a robust desensitization of postsynaptic GABAA receptors. This strongly contributes to the use-dependent synaptic depression elicited by various patterns of NGFC activity including the one detected during theta network oscillations in vivo. Synaptic depression mediated by NGFCs is likely to play an important modulatory role in the feedforward inhibition of CA1 pyramidal cells provided by the entorhinal cortex.