Volume 17, Number 7,
Issue of April 1, 1997
pp. 2543-2550
Copyright ©1997 Society for Neuroscience
The Effects of Nerve Growth Factor on Spatial Recent Memory in
Aged Rats Persist after Discontinuation of Treatment
Received Sept. 27, 1996; revised Dec. 5, 1996; accepted Dec. 11, 1996.
Karyn M. Frick1,
Donald
L. Price2,
Vassilis E. Koliatsos2, and
Alicja L. Markowska1
1 Department of Psychology, The Johns Hopkins
University, Baltimore, Maryland 21218, and 2 Departments of
Pathology, Neurology, and Neuroscience, The Johns Hopkins University
School of Medicine, Baltimore, Maryland 21205
Nerve growth factor (NGF) infusion significantly reduces spatial
recent memory deficits in aged rats, an effect that has great relevance
to the treatment of memory impairments characteristic of patients with
Alzheimer's disease. The present study was designed to examine whether
this NGF-induced improvement in spatial recent memory persists after
the discontinuation of NGF treatment, an issue of crucial importance
for the potential clinical use of this compound. Spatial recent memory
was tested in a Morris water maze delayed nonmatch-to-position task. In
addition to memory, sensorimotor skills were also examined. Four- and
22-month-old rats were tested preoperatively, infused
intraventricularly with recombinant human NGF or vehicle, and tested
both during the 4 week infusion period and during the 4 weeks after
discontinuation of the infusion. NGF significantly improved spatial
recent memory in 22-month-old rats only, during the 4th week of
infusion and for up to 4 weeks after discontinuation of the infusion.
Although NGF did not affect overall sensorimotor skills during infusion in either age group, sensorimotor skills were significantly improved both 2 and 4 weeks after discontinuation of infusion in 22-month-old rats. These findings demonstrate that the beneficial effects of NGF on
spatial recent memory can persist for up to 1 month after discontinuation of infusion and suggest that NGF can be used
intermittently for the treatment of age-associated memory dysfunction
and Alzheimer's disease.
Key words:
neurotrophins;
aging;
water maze;
delayed
nonmatch-to-position;
working memory;
body weight