A Systems Conceptualization | Neurotransmitters | Peripheral Satiety Network
A major conceptual revision for understanding the physiology
and behavior of eating has expanded the dual-center theory of hypothalamic
facilitatory and inhibitory centers for eating. The sensitive hypothalamic
eating centers are part of a broad complex of neuroregulator interactions
that includes a peripheral satiety system (gastrointestinal and
pancreatic hormones released by food passing through the gastrointestinal tract)
and a broad neural network affecting feeding, within the brain.
Eating behavior is now known to reflect an interaction between an
organism's physiological state and environmental conditions.
Salient physiological variables include the balance of various neuropeptides
and neurotransmitters, metabolic state, metabolic rate, condition
of the gastrointestinal tract, amount of storage tissue, and sensory
receptors for taste and smell. Environmental conditions include
features of the food such as taste, texture, novelty, accessibility,
and nutritional composition as well as other external conditions
such as ambient temperature, presence of other people, and stress (Blundell and Hill 1986).