Compared with controls, female patients with interstitial cystitis/painful bladder syndrome showed increased activation of a defensive emotional circuit in the context of a threat of abdominal pain [ 22].
The security situation in Britain deteriorated in the late 3rd century AD and a circuit of defensive walls were built around the city, probably between 270 and 290.
Between 1297 and 1350 the city had erected a circuit of defensive stone walls and ditches, both to impress upon outsiders the status of Norwich as a great city, but also to defend against invasion or civil disorder.
(A ) Schematic illustrating brain circuits involved in defensive behaviors.
Instead, it has been assumed, by analogy to circuits mediating conditioned defensive responses, that emotion centers for innate defensive behaviors would be located in the medial amygdala (MEA), and that downstream hypothalamic targets would similarly serve as passive relays for amygdala output (Gross and Canteras, 2012; LeDoux, 2012; LeDoux and Damasio, 2013).
However this criterion is more difficult to apply to circuits that mediate unlearned (innate) defensive behavior.
It was known as a smash-mouth circuit, a place of tough, cold-weather defensive units.
Defensive behaviors are prototypic emotional behaviors, but the relationship between the circuits that control such behaviors, and those that encode associated emotion states such as 'fear', (Adolphs, 2013) remains an open question.
In addition to their effects on basal ganglia structures and action selection, drugs also exert a tremendous influence over neural circuits regulating motivated behaviors (e.g., ingestive, reproductive and defensive behaviors), endocrine systems and the autonomic nervous system [ 165- 168].
Thus, this simple asymmetric circuit joins the two motor networks and underlies the dominance of defensive withdrawal.
