PS263 Chapter Notes - Chapter 11: Cochlear Nucleus, Startle Response, Posttraumatic Stress Disorder
Document Summary
Amygdala is one of main areas for regulating anxiety, modified by both genes and experiences. Moro reflex: sudden loud noise causes newborn to arch back, extend arms and legs, and cry. After infancy, a loud noise elicits the startle reflex: auditory info goes to cochlear nucleus in medulla and then to area in pons that commands muscles to tense. Startle reflex more vigorous if already tense, ptsd sufferers show enhanced startle reflex. Many cells in amygdala (esp in basolateral and central nuclei) get input from pain fibers and vision or hearing. Different paths through amygdala: fear of pain, fear or predators, fear of aggressive members of your own species. Different parts of amygdala: controls changes in breathing, another controls avoidance of potentially unsafe places, learning which particular places are safest. Output from amygdala to hypothalamus controls autnomic fear responses ex increased blood pressure. Amygdala has axons to areas of prefrontal cortex that control approach/avoidance responses.
