Topic 12 Flashcards
After intense exercise, beta-endorphin blood levels increase. Does this beta-endorphin come from the brain or elsewhere? Which molecule is a precursor for beta-endorphin? Can the beta-endorphin measured in the blood cross the blood brain barrier? Why/Why not?
Peripheral blood measures
POMC
No because it is a peptide
What is a PET scan? If your tracer binds to X-receptor, and under basal conditions, you have low endogenous neurotransmitter X release, would you have low or high imaging signal in regions with lots of X-receptor? If you did something to the person that caused an increase in neurotransmitter X release, would this increase or decrease availability of the X-receptors for the tracer?
PET can use radioactive tracer that binds to different opioid receptors
High
decrease
In a PET study of athletes, in which regions of the brain did they find evidence of opioid release correlated with euphoria after a 2-hour run?
anterior cingulate cortex
orbitofrontal cortex
insula
Besides opioids, which other endogenous molecule may be involved in a runner’s high?
Endocannabinoids
In rats, under what conditions can voluntary wheel running change HPA axis responses to stress? For how many weeks does a rat need to run before this effect is seen? Does the animal need to run every day for this effect to be observed?
6 weeks
no
In rats, can voluntary wheel running change any of the consequences of intense inescapable stressor exposure? How many weeks of running does it take?
Prior exercise attenuated the stress-induced learned helpless behavior and exaggerated fear
6 week
Would you expect activity in brain regions associated with sensory stimuli to be altered by voluntary wheel running in rats? How about regions associated with processing stressful stimuli? How would you measure that?
No
Activated to a lesser extent
Fos expression after stress
How do you make a rat run on a treadmill? Is treadmill training, when the animal is significantly fitter than a sedentary control, able to prevent the consequences of IS exposure? How about forced wheel running?
Shock them if they fall off.
No
Yes
Is exercise-induced stress resilience dependent on the medial prefrontal cortex? How would you test that?
NO
Lesioning the mPFC had no effect on the stress resilience provided by either 6 weeks of forced wheel run (FW) or voluntary wheel run (VW) following 100 inescapable tail shocks.
Rats always choose to run if they have a running wheel in their cage. Experimentally, how would you show wheel running is rewarding in rats? Is forced wheel running rewarding?
Conditioned placement test
yes
