RT Journal Article
SR Electronic
T1 Interneurons Provide Circuit-Specific Depolarization and Hyperpolarization
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4224
OP 4229
DO 10.1523/JNEUROSCI.5702-11.2012
VO 32
IS 12
A1 Jonas-Frederic Sauer
A1 Michael Strüber
A1 Marlene Bartos
YR 2012
UL http://www.jneurosci.org/content/32/12/4224.abstract
AB Perisoma-inhibiting interneurons (PIIs) control fundamental aspects of cortical network function by means of their GABAergic output synapses. However, whether they depolarize or hyperpolarize their target cells in the mature circuitry remains controversial. By using unitary field potential and gramicidin D perforated-patch recordings, we provide evidence that the postsynaptic effect of GABAergic synapses is fundamentally different in two regions of rat hippocampus. Signaling at PII output synapses is hyperpolarizing in CA1 principal cells (PCs) but depolarizing in dentate gyrus (DG) PCs. While the reversal potential of GABAA receptor-mediated currents is identical in both areas, ∼15 mV more negative resting potentials of DG compared with CA1 PCs underlie the opposing effects of perisomatic GABAergic transmission. Thus, the nature of PII output signaling is circuit-dependent and may therefore contribute differentially to information processing in the two brain areas.