The neural structures implicated in crying are reviewed, based on studies in animals. Brain regions involved include the anterior cingulate gyrus (a cortical structure), amygdala, thalamic tegmentum, periaqueductal gray of the midbrain, and the nucleus ambiguus of the caudal brainstem. It is hypothesized that the crying associated with colic may be a manifestation of differing developmental stages in the brain circuits involved.