Correlative Motor Behavioral and Striatal Dopaminergic Alterations Induced by 56 Fe Radiation

In recent years there has been increased interest in the study of mammalian organismic responses to heavy charged particles (HZE’s). This interest has been generated from a variety of areas including space radiobiology (Grahn, 1973) and radiotherapy (Castro et al., 1985). While a great deal of information has been generated that is concerned with the mechanisms of HZE damage and repair (Curtis, 1986; Tobias, 1985) or the early and late effects of HZE damage (Ainsworth, in press), there have been few attempts to investigate the effects of these particles on any motor behavioral parameters. The potential for HZE’s to alter behavioral performance becomes increasingly important when one considers that future space travelers, especially those who will be on long space voyages, or those who may be carrying out tasks outside the shelter of a space vehicle, may be exposed to HZE’s that can create microscopic lesions in virtually all organs of the body (see Todd, 1983 for review). The questions as to whether or not such exposure results in performance deficits and the possible relationship of these deficits to the structural specificity of damage to the brain have not been addressed very extensively. There are indications, however, from at least one experiment (Philpott et al., 1985) that mice given brief exposure to low doses of 40Ar particles showed time-dependent reductions in performance on a wire suspension task.