“…Differences between presynaptic auto-and heteroreceptors in the CA3 area of the hippocampus included the finding that GABA A receptor-mediated synaptic inhibition was more sensitive to baclofen (Lei and McBain, 2003) and to pertussis toxin and barium treatments (Thompson and Gahwiler, 1992). In measuring GABA, Glu, and other neurotransmitter release, several agonists and antagonists displayed pharmacologically distinct potencies between the presynaptic GABA B auto-and heterosynaptic receptors (Bonanno and Raiteri, 1993;Teoh et al, 1996;Bonanno et al, 1997). Now, for the first time, in the hippocampal CA1 area, we have demonstrated that the novel GABA B receptor-positive allosteric modulator, CGP7930, selectively potentiated baclofen-induced activation of presynaptic autoreceptors.…”