Effects of Radiation on Living Organisms . Early and Late Effecces of Radiation of Different Project Title: Quality and at Different Dose Rate RX-03-01-(a) 14, Scope: (Cont'd.) enables estimate of the importance of the astrocyte to brain metabolism and as an indicator of radiation damage. The unusual resistance of the shark brain to other injury (particularly to alterations in blood brain barrier) has led to an interest in studying radiation effects in this species. Sharks receive gamma exposures in the 1,000 to 30,000 R range, limited to specific brain areas and are serially sacrificed for histochemical and electron microscopic evaluation. Alterations in the blood brain barrier are evaluated using standard tracer and dye techniques, as well as the newer peroxidase method. Data relating dose and time post-exposure to changes in morphology following gamma irradiation and the measurement of functional changes in the elasmobranch brain will permit comparison of elasmobranch and mammalian responses to radiation in order to understand the importance of differences in structure to varying radiosensitivity. 15. (Carsten) Relationship cto Other Projects: At BNL Sparrow and Smith, Biology Department, investigate the relative biological effectiveness of neutrons of various energies at various doses and dose-rates using primarily plant material. The RBE of neutrons in a wide range of cellular and animal systems is being studied by Bond, and collaborators using the high capability of the RARAF as the source of : neutrons. Popenoe and Slatkin, Medical Department, study biochemical aspects of neoplasms using, in part, radiation-induced rat mammary tumors. ‘ At Argonne National Laboratory, Grahn investigates life shortening and carcinogenesis in irradiated mice over the life span; Finkel studies radiation-induced sarcomas of mice and of man with particular reference to the role of a virus in tumor formation. At Oak Ridge National Laboratory, Walberg studies radiation carcinogenesis in mice. Other related studies include those of Rossi, carried on at Columbia University, in addition to those at BNL; Vogel, University of Tennessee on rat mammary carcinogenesis and neutron irradiation; Telles, Bureau of Radiological Health, USPHS on radiation-ethionine mammary carcinogenesis; Huggins, University of Chicago, and Dao, Roswell Park on chemical carcinogenesis using the rat mammary system; and Hempelmann, University of Rochester on the association of (Shellabarger) radiation and breast cancer in man. wies related to research on the effects of radiation on the -mervous system include those of Bruner, Lovelace Foundation, on slopment of techniques for defining brain function following fation via surface and depth recording and stimulation techniques. Barnes' group at the USAF School of Aerospace Medicine is investigating radiation effects on the equilibrium function in primates, and is particu(Carsten) larly interested in the role of damage to the visual system. (See Continuation Sheet) “4479260 RX-~167