The Human Brain : From Neurone to Nervous System

The Hypothalamus and Body Weight Regulation

  1. The hypothalamus is involved in various forms of instinctive behaviour, including feeding and drinking, emotion and stress, and reproductive / sexual behaviour.
  2. Separate areas of the hypothalamus are involved in appetite (hunger) and satiety (satisfaction or fullness after a meal).
  3. Lesions of these nuclei can induce obesity or emaciation, depending on the site of the lesion.
  4. The activity of these nuclei is regulated by vagal afferent neurones carrying signals from the gastrointestinal tract and by gastrointestinal hormones released during digestion.
  5. Gastrointestinal hormones may influence body weight by acting on vagal afferents or directly on the hypothalamus.
  6. Feedback concerning the size of fat stores in the body depends on the hormones Leptin and Adiponectin produced by adipose tissue.
Key Words: Hypothalamus, feeding, satiation, NPY, vagus nerve, gastrointestinal hormones, Leptin, Adiponectin.