Naloxone-sensitive potentiation at granule cell synapses in the ventral dentate gyrus and stress ulcers.

Continuous perfusion of the granule cells in the ventral dentate gyrus with naloxone blocked the long-term potentiation (LTP) induced by high-frequency electrical stimulation of the posterolateral amygdala in freely-moving rats. This treatment also aggravated the stomach ulceration produced by cold restraint. LTP, on the other hand, attenuated the gastric stress pathology. It was suggested that a naloxone-sensitive granule cell gate modulates the impact of environmental stressors.