The α5GABAA Receptor Modulates the Induction of Long-Term Potentiation at Ventral But Not Dorsal CA1 Hippocampal Synapses

The hippocampal synapses display conspicuous ability for long-term plasticity which is thought to underlie learning and memory. Growing evidence shows that this ability differs along the long axis of the hippocampus, with the ventral CA1 hippocampal synapses displaying remarkably lower ability for long-term potentiation (LTP) compared with their dorsal counterpart when activated with high-frequency stimulation. Here, we show that low frequency, 10 Hz stimulation induced LTP more reliably in dorsal than in ventral CA1 field. Blockade of alpha5 subunit-containing GABA(A) receptors eliminated the difference between dorsal and ventral hippocampus. We propose that alpha 5GABA(A) receptor-mediated activity plays a crucial role in regulating the threshold for induction of LTP especially at the ventral CA1 hippocampal synapses. This might have important implications for the functional specialization along the hippocampus. (C) 2014 Wiley Periodicals, Inc.