Iowa gambling task (rats) anxiety and the medial prefrontal cortex de Visser, Baars, van t’ Klooster, van den Bos

Over 100 trials Net = -$2,500 Net = $2,500

Why would you make a disadvantageous choice? People with a “broken” medial Prefrontal Cortex (mPFC) ◦ Emotional control and conflict resolution  Decision making in short… ◦ Malfunction = bad decisions

mPFC In rats: mPFC involved in anxiety & decisions May be impaired in people with high anxiety

Things you are allowed to do with rats and not humans… Artificially deactivate mPFC ◦ Inject GABA agonists  GABA receptor A - muscimol  GABA receptor B - baclofen

Anxiety -Inactivation of mPFC INCREASES anxiety

Nothing “Good” choice “Bad” choice

Nothing “ Good ” choice “ Bad ” choice 3 pellets: 90% quinine 10% sucrose 1 pellets: 20% quinine 80% sucrose

5 days testing 2 days rest 4 days testing ’8’9’ 10 trials / day 20 trials / day I.C. injection each day

Trials All animals included Median = x “Good performer” = >x “Bad performer” = <x

???Base line values of what??? 1.The entire population (good and bad; trial 41-60)? 2.The respective “good” and “bad” population; trial 41-60? 3.The individual only; trial 41-60?

Exploration Defined strategy mPFC Amygdala & ventral striatum Van Den Bos 2007 Trials 1-60Trials

Exploration Defined strategy mPFC Amygdala & ventral striatum

Inactivation of mPFC increases anxiety Increased anxiety Poor decision making ???? What is this experiment?

Anxiety / fear HPA axis Corticosteroids mPFC Current paper Koot poster

Corticosterone (stress in a needle) Susanne Koot’s poster

[(A*B)+(C*D)]*100 either or 100x $10050% -$ % -$7, $10090% -$1, % -$3, $5050% -$ % -$10, $5090% -$1, % -$8, both 100x $100100% -$ % -$2, $100100% -$1, % -$2, $50100% -$ % $2, $50100% -$ % $2, Over 100 trials Net = -$2,500 Net = $2,500