Figure 2.
The depressing actions of PYY3-36 are consistent with a postsynaptic activation of Y2 receptors in POMC neurons. A, PYY3-36 reduced the spike frequency in a dose-dependent manner. B, The graph shows the time course of PYY3-36 (open circles) and NPY13-36 (filled circles) inhibitory actions on the frequency of action potentials in identified arcuate POMC cells. C, The actions of PYY3-36 and NPY13-36, two agonists of Y2 receptors, on POMC neuron membrane potential were dose dependent. D, Both Y1 (Pro34NPY or d-Arg25NPY) and Y2 (PYY3-36 or NPY13-36) receptor agonists hyperpolarized POMC neurons. BIBP3226, a selective Y1 receptor antagonist, eliminated the Y1 receptor-mediated hyperpolarization but did not affect Y2 receptor-dependent changes in membrane potential.