 Likewise, stimulation of hippocampal neurons fails to produce action potentials in the nucleus accumbens; however, these hippocampal neurons have been shown to switch their targets in the nucleus accumbens to the up state.As long as these neurons remain in the up state, stimulation of prefrontal cortical neurons has a much higher likelihood of producing action potentials in the nucleus accumbens.Thus, the hippocampus serves as the gatekeeper for information flow from the prefrontal cortex to the nucleus accumbens, such that its action permissively gates these synapses.