Ba. Kinney et al., Evidence that ames dwarf mice age differently from their normal siblings in behavioral and learning and memory parameters, HORMONE BEH, 39(4), 2001, pp. 277-284
There is strong evidence supporting the deleterious effects of aging on lea
rning and memory and behavioral parameters in normal mice. However, little
is known about the Ames dwarf: mouse, which has a Prop-1 gene mutation resu
lting in deficiencies in growth hormone, thyroid-stimulating hormone, and p
rolactin. These mice are much smaller and live significantly longer than th
eir normal siblings. Using the elevated plus-maze, locomotor activity meter
s, and an inhibitory avoidance learning task, the present study compared Am
es dwarf mice to their normal siblings. Results showed that Ames dwarf mice
did not experience an age-related decline in locomotor activity when compa
red to their young counterparts. Furthermore, old dwarf mice did not differ
from the young groups in inhibitory avoidance retention, while old normal
animals performed more poorly than both young groups on this test. Elevated
plus-maze behavior did not differ in the old normal versus dwarf groups, b
ut the old groups did differ from the young. Results indicate that both old
groups experienced a significant decline in anxiety with age. Taken togeth
er, these results indicate that multiple hormone deficiencies resulting fro
m a lack of primary pituitary function have beneficial effects on cognitive
function and locomotor behavior in advanced age. In fact, the Ames dwarf m
ouse may provide a model for studies of delayed mental as well as physical
aging. (C) 2001 Academic Press.