Psych Studies

• Background


  - Studied the role of stress hormones on memory

  - Used rats, placed them in a maze
• Aim


  - To determine the effect of glucocorticoids (stress hormones) on memory
• Procedure


  - Rats randomly allocated to one of two conditions/situations

  
  

  Treatment group:

  - Newborns handled daily by researchers, for 3 weeks

  - Day of birth, until day of weaning

  - During this time, taken away from their mothers for 15 mins per day

  - Placed in a plastic container lined with a paper towel

  - Brushed for an intense 15 minutes --> simulated grooming of mother rat

  - Nurtured

  
  

  Control group:

  - Taken away from mother

  - No handling

  - Therefore impoverished

  
  

  - To test the effect of elevated stress hormones over their lifetime, 2yr old rats put in pool of milky water

  - Platform in the pool

  - Rats tried to reach the platform, to escape the water - based on their memories of previous attempts.

  - Route of the rats was tracked
• Results

  - High levels of glucocorticoids - stress hormones - in the early life of a rat, resulted in changes that affected the rats in old age

  - Increased exposure to adrenal glucocorticoids (control group) accelerated hippocampal neuron loss and cognitive impairments in aging

  - Rats in control group took more circuitous route to reach platform when they reach old age

  - Hippocampal cell loss and pronounced spatial memory deficits came with age in neglected rats

  - Almost absent in rats groomed by researchers
• Conclusion


  - Appears that extra stroking/grooming led to activation of genes responsible for reaction to stress response

  - The genes helps the young rate manage stress

  - Leads to better memory, and a longer and healthier life

  - This study demonstrates the function of glucocorticoids,