these studies indicated that after 3 hr and 6 hr in a free operant avoidance-escape stress procedure , the experimental rats able to avoid or escape shock showed greater increases in na turnover ( lower na levels and higher mhpg-so4 levels ) in specific brain regions ( i.e. , the hypothalamus , amygdala , and thalamus ) than the yoked rats unable to control the same shock .
C0028351
na
C0036974
shock