Final answer:
α-MSH produced from POMC neurons binds to MC4R in the Paraventricular nucleus and reduces food intake and increases adaptive thermogenesis, but does not reduce physical activity.
Step-by-step explanation:
α-MSH produced from POMC neurons binds to the melanocortin receptor (MC4R) on neurons in the Paraventricular nucleus and has multiple effects. One of its known effects is to reduce food intake by its action in the hypothalamus. Additionally, it is associated with increasing adaptive thermogenesis, which is the body's generation of heat in response to environmental changes such as cold exposure or diet. While it has a clear role in energy homeostasis, it does not directly reduce physical activity; instead, it modulates energy expenditure and appetite control.
Another aspect of this hormonal interaction is related to the stress response. For example, stress can lead to an increase in the production of corticotropin-releasing hormone (CRH), which in turn affects neurons in the locus coeruleus (LC) that modulate attention and behavior. It's part of the body's 'fight or flight' mechanism which increases arousal and can facilitate behavioral flexibility in threatening situations.