Early-life undernutrition impairs the development of the learning and short-term memory processes mediating performance in a conditional-spatial discrimination task.
Previously undernourished and well-nourished control rats 23, 30, 40, and 90 days old were compared in a win-shift version of a conditional-spatial discrimination task. Control animals at each age were able to reach criterion on this problem. In contrast, the underfed rats were unable to solve this problem until they were at least 40 days old. The short-term memory of the 40- and 90-day-olds was further evaluated by increasing the interval between the forced run and choice run to 30, 60, and 180 s. Control animals could bridge all intervals; however, the undernourished animals' performance fell to chance when the interval was only 60 s. Thus, early-life undernutrition severely impaired the development of the ability of animals to solve spatial-conditional discrimination tasks and permanently impaired their short-term memory capacity. A simple threshold model relating undernutrition, brain development, and behavior is proposed to account for these data.
Castro
C A
CA
Department of Psychology, University of Colorado, Boulder 30809-0345.
Tracy
M
M
Rudy
J W
JW
D000818:Animals; D000831:Animals, Newborn; D001288:Attention / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006624:Hippocampus / Q000503:physiopathology; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D011502:Protein-Energy Malnutrition / Q000503:physiopathology*; D051381:Rats