Total body 4.5 Gy gamma irradiation-induced early delayed learning and memory dysfunction in the rat.
In an attempt to determine the consequences of total body radiation damage on learning and memory in the rat, twenty-eight male Wistar rats aged 4 months received 4.5 Gy total body gamma-irradiation (TBI) while 28 rats received sham irradiation. Sequential behavioral studies of negative reinforcement including a/ one- and b/ two-way avoidance tasks were undertaken. a/ One-way avoidance test: this test was performed before and after TBI. Prior to irradiation both groups were similar. At 20 days (D) and at 3 months post-TBI, irradiated rats had a significantly lower percentage of avoidance than controls but no statistical difference was found at 5 months post-TBI. b/ Two-way avoidance test: this test was performed only after TBI. At days 21, 22, 23, 24, (leaming) and at 4 or 6 months (recalls) post-TBI the mean percentage of avoidance was significantly lower in irradiated than in control rats. This study demonstrates that total-body exposure to 4.5 Gy gamma-irradiation induces behavioral dysfunction affecting learning and transitorily memory. These results suggest that a relatively low dose of total body irradiation can induce neurological complications, which persist 4-6 months later.
Lamproglou
I
I
Laboratoire de Chimie et Biophysique des Traceurs, Faculté de Médecine, Xavier Bichat, Paris, France. ilamprogl@aol.com
Martin
S
S
Diserbo
M
M
Multon
E
E
Petiet
A
A
Colas-Linhart
N
N
Bok
B
B
Martin
C
C
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology / Q000528:radiation effects*; D004195:Disease Models, Animal; D005720:Gamma Rays / Q000009:adverse effects*; D007859:Learning Disabilities / Q000503:physiopathology*; D008297:Male; D008568:Memory / Q000528:radiation effects; D008569:Memory Disorders / Q000503:physiopathology*; D011829:Radiation Dosage; D051381:Rats; D017208:Rats, Wistar; D015996:Survival Rate; D013997:Time Factors