title: Long-Term Cognitive Functioning in Single-Dose Total-Body Gamma-Irradiated Rhesus Monkeys ( Macaca mulatta ).
abstract: In this study, the effects of a potentially lethal radiation exposure on the brain for long-term cognitive sequelae were investigated using Rhesus macaques ( Macaca mulatta ) adopted from other facilities after analysis of acute radiation response via the Centers for Medical Countermeasures against Radiation (CMCR) network. Fifty-nine animals were given the opportunity to participate in cognitive cage-side testing. The animals that received single-dose gamma irradiation were significantly less likely to engage in cognitive testing than the controls, suggesting that irradiated animals may have differences in cognitive ability. Five irradiated (6.75-8.05 Gy) and three naïve control animals self-selected, were extensively trained and administered a simple visual discrimination with reversal (SVD+R) task 2-3 times per week for 11-18 months. Each session consisted of 30 trials in which the animals were required to choose the correct visual stimulus for a food reward. After the initial presentation, the stimulus that signaled the presence of food was twice reversed once the animal reached criterion (90% accuracy across four consecutive sessions). While the limited sample size precluded definitive statistical analysis, irradiated animals took longer to reach the criterion subsequent to reversal than did control animals, suggesting a relative deficiency in cognitive flexibility. These results provide preliminary data supporting the potential use of a nonhuman primate model to study radiation-induced, late-delayed cognitive deficits.
authors.affiliation: Department of a   Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina.|d   Department of Psychology, Averett University, Danville, Virginia 24541.
authors.forename: David B
authors.initials: DB
authors.lastname: Hanbury
authors.affiliation: b   Department ofRadiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina.|c   Department of Brain Tumor Center of Excellence, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157.|e   Department of Psychology, Mars Hill University, Mars Hill, North Carolina 28754.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Peiffer
authors.affiliation: Department of a   Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
authors.forename: Greg
authors.initials: G
authors.lastname: Dugan
authors.affiliation: Department of a   Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
authors.forename: Rachel N
authors.initials: RN
authors.lastname: Andrews
authors.affiliation: Department of a   Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cline
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology* / Q000528:radiation effects*; D003071:Cognition / Q000528:radiation effects*; D004192:Discrimination, Psychological / Q000528:radiation effects; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects*; D008253:Macaca mulatta; D008297:Male