the concentrations of neurotransmitters in the brain showed 2 peaks during the overcrowding : at the beginning of the stress ( day 2 ) there was a sharp rise of 5-hydroxy-indoleacetic acid ( 5-hiaa ) , a metabolite of serotonin , and in the second week ( day 10 ) there was another rise of 5-hiaa , together with serotonin and noradrenaline .
C0086045
concentrations
C0006104
brain