Limits...
Fear and the Defense Cascade: Clinical Implications and Management.

Kozlowska K, Walker P, McLean L, Carrive P - Harv Rev Psychiatry (2015 Jul-Aug)

Bottom Line: Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei.Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions.Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state.

View Article: PubMed Central - PubMed

Affiliation: From the Disciplines of Psychiatry (Drs. Kozlowska and McLean) and of Paediatrics and Child Health (Dr. Kozlowska), University of Sydney Medical School; Brain Dynamics Centre, Westmead Millennium Institute for Medical Research and University of Sydney Medical School (Dr. Kozlowska); The Children's Hospital at Westmead, Westmead, New South Wales (Dr. Kozlowska); Peter Walker & Associates, Randwick, New South Wales (Mr. Walker); Brain and Mind Research Institute, University of Sydney Medical School (Dr. McLean); Westmead Psychotherapy Program and Sydney West and Greater Southern Training Network, Western Sydney Local Health District (Dr. McLean); Department of Anatomy, School of Medical Sciences, University of New South Wales (Dr. Carrive) (all Australia).

ABSTRACT
Evolution has endowed all humans with a continuum of innate, hard-wired, automatically activated defense behaviors, termed the defense cascade. Arousal is the first step in activating the defense cascade; flight or fight is an active defense response for dealing with threat; freezing is a flight-or-fight response put on hold; tonic immobility and collapsed immobility are responses of last resort to inescapable threat, when active defense responses have failed; and quiescent immobility is a state of quiescence that promotes rest and healing. Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei. Unlike animals, which generally are able to restore their standard mode of functioning once the danger is past, humans often are not, and they may find themselves locked into the same, recurring pattern of response tied in with the original danger or trauma. Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions. Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state. The process of shifting the neural pattern is the necessary first step in unlocking the patient's trauma response, in breaking the cycle of suffering, and in helping the patient to adapt to, and overcome, past trauma.

No MeSH data available.


Related in: MedlinePlus

States of the defense cascade. The diagram depicts the states of arousal, flight or fight, freezing, and tonic/collapsed immobility in terms of patterns of neural activity in the different structures and pathways of the defense cascade network. I. Arousal, the first step to the activation of the defense cascade, can be viewed as the activation of the hypothalamus pathway. II. Fight or flight involves the activation of the hypothalamus and lateral periaqueductal gray. III. Freezing—flight or fight put on hold—involves activation of the following: hypothalamus pathway; unmyelinated vagal pathway from the dorsal motor nucleus (which opposes the sympathetic activation); lateral periaqueductal gray; and ventrolateral periaqueductal gray (which opposes activation of the lateral periaqueductal gray). IV. Tonic/collapsed immobility involves activation of the unmyelinated vagal pathway from the dorsal motor nucleus and of the ventrolateral periaqueductal gray pathway. In tonic/collapsed immobility the hypothalamus pathway is not activated. The filled circles depict activated neurons, whereas the open circles depict non-activated neurons. ACTH, adrenocorticotropic hormone; DMN, dorsal motor nucleus of the vagus; Hyp, hypothalamus; LPAG, lateral periaqueductal gray; VLPAG, ventrolateral periaqueductal gray; X, vagus nerve.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4495877&req=5

Figure 2: States of the defense cascade. The diagram depicts the states of arousal, flight or fight, freezing, and tonic/collapsed immobility in terms of patterns of neural activity in the different structures and pathways of the defense cascade network. I. Arousal, the first step to the activation of the defense cascade, can be viewed as the activation of the hypothalamus pathway. II. Fight or flight involves the activation of the hypothalamus and lateral periaqueductal gray. III. Freezing—flight or fight put on hold—involves activation of the following: hypothalamus pathway; unmyelinated vagal pathway from the dorsal motor nucleus (which opposes the sympathetic activation); lateral periaqueductal gray; and ventrolateral periaqueductal gray (which opposes activation of the lateral periaqueductal gray). IV. Tonic/collapsed immobility involves activation of the unmyelinated vagal pathway from the dorsal motor nucleus and of the ventrolateral periaqueductal gray pathway. In tonic/collapsed immobility the hypothalamus pathway is not activated. The filled circles depict activated neurons, whereas the open circles depict non-activated neurons. ACTH, adrenocorticotropic hormone; DMN, dorsal motor nucleus of the vagus; Hyp, hypothalamus; LPAG, lateral periaqueductal gray; VLPAG, ventrolateral periaqueductal gray; X, vagus nerve.

Mentions: Central to the analytical framework for this article is the defense cascade. All defense responses in the animal model of the defense cascade—arousal, freezing, flight or fight, tonic immobility, collapsed immobility, and quiescent immobility—are responses to threat mediated by neural circuits involving the extended amygdala, hypothalamus, periaqueductal gray (PAG), ventral pontine tegmentum, ventral and dorsal medulla, and spinal cord.22–25 Each defense response has a signature neural pattern that corresponds to a combination of activated connections within a descending neural network (see Figures 1 and 2). This descending network terminates at the level of the effector organs, where it controls a somatomotor component (which involves skeletal muscle), an autonomic/visceromotor component (which involves the viscera), and a pain-processing component. Changes in the patterns of activity of that network mediate the defense cascade and define the different types of defense responses that, taken together, form the defense repertoire of mammalian species. In any particular situation the defense response will be a function of the species-specific defense repertoire,8 genetic variations among strains,26 characteristics of the threat, and context in which it occurs, all influenced by individual differences.§,27


Fear and the Defense Cascade: Clinical Implications and Management.

Kozlowska K, Walker P, McLean L, Carrive P - Harv Rev Psychiatry (2015 Jul-Aug)

States of the defense cascade. The diagram depicts the states of arousal, flight or fight, freezing, and tonic/collapsed immobility in terms of patterns of neural activity in the different structures and pathways of the defense cascade network. I. Arousal, the first step to the activation of the defense cascade, can be viewed as the activation of the hypothalamus pathway. II. Fight or flight involves the activation of the hypothalamus and lateral periaqueductal gray. III. Freezing—flight or fight put on hold—involves activation of the following: hypothalamus pathway; unmyelinated vagal pathway from the dorsal motor nucleus (which opposes the sympathetic activation); lateral periaqueductal gray; and ventrolateral periaqueductal gray (which opposes activation of the lateral periaqueductal gray). IV. Tonic/collapsed immobility involves activation of the unmyelinated vagal pathway from the dorsal motor nucleus and of the ventrolateral periaqueductal gray pathway. In tonic/collapsed immobility the hypothalamus pathway is not activated. The filled circles depict activated neurons, whereas the open circles depict non-activated neurons. ACTH, adrenocorticotropic hormone; DMN, dorsal motor nucleus of the vagus; Hyp, hypothalamus; LPAG, lateral periaqueductal gray; VLPAG, ventrolateral periaqueductal gray; X, vagus nerve.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495877&req=5

Figure 2: States of the defense cascade. The diagram depicts the states of arousal, flight or fight, freezing, and tonic/collapsed immobility in terms of patterns of neural activity in the different structures and pathways of the defense cascade network. I. Arousal, the first step to the activation of the defense cascade, can be viewed as the activation of the hypothalamus pathway. II. Fight or flight involves the activation of the hypothalamus and lateral periaqueductal gray. III. Freezing—flight or fight put on hold—involves activation of the following: hypothalamus pathway; unmyelinated vagal pathway from the dorsal motor nucleus (which opposes the sympathetic activation); lateral periaqueductal gray; and ventrolateral periaqueductal gray (which opposes activation of the lateral periaqueductal gray). IV. Tonic/collapsed immobility involves activation of the unmyelinated vagal pathway from the dorsal motor nucleus and of the ventrolateral periaqueductal gray pathway. In tonic/collapsed immobility the hypothalamus pathway is not activated. The filled circles depict activated neurons, whereas the open circles depict non-activated neurons. ACTH, adrenocorticotropic hormone; DMN, dorsal motor nucleus of the vagus; Hyp, hypothalamus; LPAG, lateral periaqueductal gray; VLPAG, ventrolateral periaqueductal gray; X, vagus nerve.
Mentions: Central to the analytical framework for this article is the defense cascade. All defense responses in the animal model of the defense cascade—arousal, freezing, flight or fight, tonic immobility, collapsed immobility, and quiescent immobility—are responses to threat mediated by neural circuits involving the extended amygdala, hypothalamus, periaqueductal gray (PAG), ventral pontine tegmentum, ventral and dorsal medulla, and spinal cord.22–25 Each defense response has a signature neural pattern that corresponds to a combination of activated connections within a descending neural network (see Figures 1 and 2). This descending network terminates at the level of the effector organs, where it controls a somatomotor component (which involves skeletal muscle), an autonomic/visceromotor component (which involves the viscera), and a pain-processing component. Changes in the patterns of activity of that network mediate the defense cascade and define the different types of defense responses that, taken together, form the defense repertoire of mammalian species. In any particular situation the defense response will be a function of the species-specific defense repertoire,8 genetic variations among strains,26 characteristics of the threat, and context in which it occurs, all influenced by individual differences.§,27

Bottom Line: Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei.Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions.Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state.

View Article: PubMed Central - PubMed

Affiliation: From the Disciplines of Psychiatry (Drs. Kozlowska and McLean) and of Paediatrics and Child Health (Dr. Kozlowska), University of Sydney Medical School; Brain Dynamics Centre, Westmead Millennium Institute for Medical Research and University of Sydney Medical School (Dr. Kozlowska); The Children's Hospital at Westmead, Westmead, New South Wales (Dr. Kozlowska); Peter Walker & Associates, Randwick, New South Wales (Mr. Walker); Brain and Mind Research Institute, University of Sydney Medical School (Dr. McLean); Westmead Psychotherapy Program and Sydney West and Greater Southern Training Network, Western Sydney Local Health District (Dr. McLean); Department of Anatomy, School of Medical Sciences, University of New South Wales (Dr. Carrive) (all Australia).

ABSTRACT
Evolution has endowed all humans with a continuum of innate, hard-wired, automatically activated defense behaviors, termed the defense cascade. Arousal is the first step in activating the defense cascade; flight or fight is an active defense response for dealing with threat; freezing is a flight-or-fight response put on hold; tonic immobility and collapsed immobility are responses of last resort to inescapable threat, when active defense responses have failed; and quiescent immobility is a state of quiescence that promotes rest and healing. Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei. Unlike animals, which generally are able to restore their standard mode of functioning once the danger is past, humans often are not, and they may find themselves locked into the same, recurring pattern of response tied in with the original danger or trauma. Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions. Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state. The process of shifting the neural pattern is the necessary first step in unlocking the patient's trauma response, in breaking the cycle of suffering, and in helping the patient to adapt to, and overcome, past trauma.

No MeSH data available.


Related in: MedlinePlus