Harrison N L, Lange G D, Barker J L
Laboratory of Neurophysiology, National Institute for Neurological and Communicative Disorders and Stroke, Bethesda, MD 20892.
Neurosci Lett. 1988 Feb 15;85(1):105-9. doi: 10.1016/0304-3940(88)90437-5.
GABA-mediated monosynaptic inhibitory postsynaptic currents were recorded at synapses between embryonic rat hippocampal neurons in culture. The GABAB receptor agonist L(-)-baclofen reduced inhibitory postsynaptic current amplitude substantially at 10 microM, while the D(+)-isomer of baclofen was without effect. L(-)-Baclofen did not increase postsynaptic membrane conductance or block postsynaptic membrane responses to GABA. It is concluded that L(-)-baclofen depresses GABA-mediated inhibitory postsynaptic potentials by a presynaptic action at GABAB receptors on or near the terminals of the inhibitory neuron. The possible physiological importance of these presynaptic 'autoreceptors' is discussed.
