Neurobiology Flashcards
what is the appetitive system?
Dopamine - mediates seeking and pleasure
what is the aversive system?
Serotonin - mediates threat and survival
what orchestrates the stress response?
Amygdala
what mediates the fight or flight response?
Periaqueductal Gray
what is responsible for memory and learning?
hippocampus
what mediates emotions of fear
cingulate cortex
how is stress processed in the brain and how might it be inhibited?
‘bottom up processing’ + limbic system led
can be altered by cognitive means ‘top down processing’
e.g. if you are expecting to get a fright the stress response is inhibited
What is the pathophysiology of Anxiety and PTSD?
Anxiety - overactive stress response mechanism (affect amygdala + hippocampus)
PTSD - overactive stress response damaged by ‘overload’ during traumatic event (loss of top-down inhibition + cortisol control over stress response)
What release cortisol and what effect does cortisol have?
hypothalamus releases via pituitary gland
Cortisol mediates and shuts down stress response
How do anxiolytics then work to reduce stress response?
Act on GABA-A to allosterically increase its inhibitory function
disruption of what Axis is linked to depression
HPA Axis (Hypothalamus, Pituitary, Adrenal Axis)
What is the major ACh producing region in the brain
nucleus basalis of meynert (become damaged in alzheimers by aB amyloid plaques + neurofibrillary tangles [tau protein])
How might schizophrenia appear on CT/MRI
enlarged ventricles
Pathophysiology of schizophrenia
subcortical dopamine hyperactivity causes psychosis
mesocortical dopamine dopamine hypoactivity causes negative symptoms
3 relevant parts of brain in addiction
Nucleus accumbens is a positive motivator for drug use
Prefrontal cortex is a negative motivator for drug use
Orbitofrontal cortex makes the final decision
