29. Cholinergic Signaling in the Medial Prefrontal Cortex Potentiates Learned Helplessness

Acetylcholine (ACh) signaling is implicated in the etiology of depression, but is also important for learning, memory, and attention, suggesting that optimal levels are beneficial, while excessive increases are detrimental to affective health. Prolonged ACh signaling during highly stressful events could therefore lead to negative encoding bias, in which stressful experiences are both attended to, and encoded, more potently, leading to increased depressive symptoms. Therefore, we recorded ACh transients from medial prefrontal cortex (mPFC) during learned helplessness to evaluate parameters under which cholinergic signaling might alter information processing during stressful events.