Fig. 3

A hypothetical auto-modulatory caudal brainstem mechanism for CARTp–CRF receptor interactions to affect feeding. We raise the hypothesis that CARTp may inhibit food intake via a putative receptor on a target neuron at some level in the dorsal hindbrain. CARTp could thus act via a CRF intermediate, which, via tonic lateral inhibition or perhaps via an inhibitory interneuron mechanism, attenuates the CARTp hypophagia. In the absence of stress activation, addition of a CRF antagonist would not by itself impact feeding but simply block CRF receptors, resulting in the loss of its tonic inhibition of the CARTp and subsequently in the unmasking of a full CARTp hypophagic behavioral response