Trauma and relevant brain structures

Amygdala

-bulbar structure at the end of the hippocampus -mediates the crisis response -makes connections with thalamic pain centers -initiates REM sleep

Cerebral cortex in trauma

-cortical neuronal loss and dysfunction in those who have suffered significant stress and trauma

Trauma and corpus callosum

-early stress results in decreased hemispheric integration -smaller in those with childhood abuse and sexual abuse

Orbital Medial Prefrontal Cortex

-first region of frontal lobe to develop -located within frontal lobes and just above the orbits of the eyes -serves an inhibitory function in response to stress in other regions of the brain -regulates planning behavior associated with reward and punishment -role in emotional processing -right side OMPC is master regulator of limbic system -assesses the reality of the danger -modulates timing of emotional response

Hippocampus dysfunction

-inability to integrate memories into coherent narrative keep persons experiences fragmented, timeless and not part of ones self. -harder to process new experience -memory cannot be stored and cannot learn from experience, then arousing stimuli are perceived as threatening and person may react through aggression or withdrawal -replication of new neurons is possible in hippocampus

Anterior Cingulate

-last step before consciousness -gatekeeper of emotion -decides which emotional information to pay attention to -CEO of brain -orchestrates the autonomic, neuroendocrine and behavioral expression of emotions

Anterior cingulate and trauma

-smaller in volume in patients with PTSD

Cerebral cortex dysfunction

-underdeveloped cortex are less able to modulate emotion, inhibit the emotional lower brain and problem solve -decrease in cortical activation and increase in anterior regions of the cingulate and insula occur in depression and anxiety symptoms

kindling

-when amygdala is overactivated and irritable -lowering of the excitability threshold of neurons -rendering person increasingly likely to develop certain symptoms

Dysfunction of amygdala

-with repeated stress, kindling causes reactions to be set off by stimuli that were previous sub-threshold -neuronal excitability of amygdala may cause panic attacks or temporal lobe seizures -irritability implicated in ADHD, PTSD, borderline personality disorder

Brain functining

Any event that is experienced as overwhelming by the individual has the potential to affect brain functioning

Hypothalamus in trauma

During stress amygdala can transmit signals directly to hypothalamus through the orbitofrontal cortex and bypass other areas in the cerebral cortex. -IMMEDIATE fight or flight

Limbic system

Emotional brain Hippocampus Thalamus Amygdala Hypothalamus Orbital Medial Prefrontal Cortex Anterior Cingulate

Trauma and the Amygdala

Two types of reactions to traumatic events undermodulation overactivation

Temporal lobe

auditory processing receptive language memory functions

Pre-frontal cortex

begins to myelinate in adolescence and continues until late 20's. regulates emotions and generalization of fear behavior exerts inhibitory influence over limbic system

Insula

buried deep within the folds of the cortex -means to connect body state to the expression and emotion of behavior

Thalamic dysregulation

can result in significant memory problems -may be unable to integrate memories into the present and personal memory into identity -memories are isolated from consciousness and may be cause of nightmares and flashbacks

Cerebellum

coordinates motor, social and cognitive functioning -reptilian brain -regulates level of arousal, some reflexes , cardiovascular functions

Locus Ceruleus

dense group of neurons found on both sides of the pons in the brain stem between the medula oblongata and midbrain, with projections to the amygdala, prefrontal cortex and hippocampus

Left hemisphere defecits

failure of left hemisphere functioning during states of extreme arousal -left hemisphere responsible for tendency to seek solutions and take actions. left hemisphere deficits occur most frequently in those who have had trauma -cant put experience into words (speechless with terror)

Thalamus and trauma

high levels of arousal during traumatic experiences are through to lead to altered thalamic processing

Dysfunction of hypothalamus

hormonal equilibrium is altered from severe stress in childhood so that genetic expression can be affected across generations -an intense single stimulation of the amygdala produces lasting changes in neuronal excitability and behavior in stress response

Overactivation fo the amygdala and trauma

hypoarousal of the prefrontal cotrtex activation of the amygdala "irritable amygdala"

Dysfunction of connection between hemispheres

implicated in alexithymia, somatization, depression, dissociateive disorders, borderline personality disorders, substance abuse, mania

OMPC dysfunction

individuals with dissociative disorders have increased activation of the orbital frontal cortex that inhibits activation of the amygdala -early development attachment problems, OMPFCs ability to regulate is reduced and long standing relationship difficulties may ensue

Parietal lobe

linking of senses with motor abilities creation of the experience of a sense of our body in space

Thalamus

located deep in the brain -relay station for top-down, bottom-up neural networks -connects cortex to limbic system -all sensory information except smell routed through thalamus to cerebral cortex

Hypothalamus

located deep in the middle and base of brain where the brain and nervous system intersect and communicate with endocrine system -regulates BP, body temperature, sleep, appetite, glucose levels

Hippocampus

located deep within the brains unconscious core -important for explicit memory, reality testing and inhibition of the amygdala -allows formation of a coherent narrative about personal history -not developed until 16-18 months

Corpus Callosum

long neural fibers that connect right and left hemispheres

Under Modulation of the amygdala and trauma

medial prefrontal cortex is hyperactive inhibition of the amygdala

Frontal lobe

motor behavior expressive language executive functioning abstract reasoning directed attention pre-frontal cortex

OMPC in trauma

reciprocal relationship between the amygdala and OMPFC determines how we handle emotional experience -connections shaped in early experiences and attachment experiences -facial expressions of caregiver impact dopamine levels -mother acts as OMPC until develops -activity decreased during increased stress and problem solving part of brain is impaired

Trauma and cerebellar vermis

reduced size of this structure has been found in traumatized children and this has been linked to numerous disorders such as ADHD, depression, bipolar disorder, schizophrenia and autism

Trauma and hippocampus

smaller in traumatized individuals who have sufferred physical or sexual abuse -during high states of arousal, amygdala and hippocampal networks become disassociated so learning is impaired -increased levels of cortisol damages dendrites in hippocampus and cause cell death -glucocorticoids excreted during traumatic event shut down the hippocampus and prevent memory from being stored

Trauma and locus ceruleus

stress activates this structure Norepinephrine is made SAM and HPA axis are stimulated and this inhibits frontal lobe functions to instincts can over-ride cognition

Cerebral cortex

thinking part of our brain -organizes experiences and determines how we react

Locus ceruleus dysfunction

this complex feedback loop, if left unchecked can result in chronic anxiety, fear, intrusive memories and health problems such as hypertension, tachycardia, bladder infections, asthma, migraines, fibromyalgia, IBS, GERD, ulcers, eating disorders and thermoregulation

Right brain phenomena

traumatic memories stored as images, sensations, and emotions, not in a coherent narrative and context -mute in terms of responding verbally (cant talk about it so act out feelings) -process negative emotional states but not positive

Occipital lobe

visual processing

cerebellar vermis

worm shaped structure between both parts of the cerebellum -helps regulates activity in the limbic system -important for regulating emotional balance, attention and posture