One ethical situation Dr. Gilliland described related to serotonin involves the "Gut Check" physiological response. This response, mediated by serotonin—which is part of the biochemical communication system between the brain and the gastrointestinal tract—occurs when a person is faced with a stressful or ethically challenging situation. It signals how stress relates to a person's actions in those ethical situations by connecting emotional and physiological stress reactions with decision-making processes. This highlights the role of serotonin in how gut feelings influence ethical behavior under stress contexts. This "Gut Check" concept reflects how serotonin signals bodily responses that link stress and ethical decision-making, underpinning the gut-brain communication in guiding moral and ethical actions in stressful conditions.