Influence of acute and repeated interleukin-2 administration on spatial learning, locomotor activity, exploratory behaviors, and anxiety

Interleukin-2 (IL-2), released from activated T cells, influences central n eurochemical functioning, and IL-2 immunotherapy in cancer patients may pro voke neuropsychiatric and cognitive disturbances. In this study, acute, sys temic IL-2 did not influence Morris water-maze performance in mice. In cont rast, chronic IL-2 impaired performance when the position of the escape pla tform varied over days but was without effect when the platform position wa s fixed. These effects could not be attributed to illness, because IL-I bet a, which induces marked malaise, did not influence water-maze performance. Chronic IL-2 produced modest reductions in exploration and approach to a no vel stimulus, effects not seen after acute treatment, but did not influence spontaneous alternation performance or behavior in an elevated plus-maze t est. Thus, repeated IL-2 may influence spatial working memory without affec ting habituation/attentional attentional processes or anxiety.