the effects of predictable and unpredictable shock on concentrations of serotonin ( 5-hydroxytryptamine , 5-ht ) , 5-hydroxyindoleacetic acid ( 5-hiaa ) , tryptophan ( tp ) and noradrenaline ( na ) have been studied in 7 regions of rat brain .
C0036974
shock
C0028351
noradrenaline