Time-dependent variations of central norepinephrine and dopamine following antigen administration

Administration of sheep red blood cells (10(6) cells, i.p.) resulted in central norepinephrine (NE) and dopamine (DA) changes which corresponded with the time of the peak immune response. These amine variations, however, appeared to be specific to certain brain regions. The increased accumulation of the NE metabolite, 3-methoxy-4-hydroxyphenylethylene glycol, was evident in hypothalamus, locus coeruleus and hippocampus and a moderate reduction of NE was evident in the hypothalamus. Alterations of DA levels or utilization appeared in mesocorticolimbic structures (i.e. nucleus accumbens and prefrontal cortex) but not in striatum. This profile of transmitter changes was reminiscent of that previously shown to be induced by uncontrollable stressors and the possibility was offered that antigenic challenge is interpreted as a stressor by the central nervous system.