1. Defensive responses in invertebrates 2. Introduction to defensive behavior in vertebrates 3. Neural circuits of fear and defensive behavior 4. Fear-associated factors modulating TI 5. Environmental, ecological and methodological factors of TI Modulation 6. The neuroethological approach to defense in rabbits 7. Neurophysiological mechanisms of TI 8. Neuromediators, brain areas and circuits involved in defense responses 9. Autonomic correlates of defense responses 10. Neuroendocrine correlates of stress and TI 11. Pain control during TI and other immobility models 12. TI as an adaptive response and a recovery mechanism promoting survival