The Journal of Neuroscience, March 15, 1999, 19(6):2337-2346
Embryonic and Postnatal Injections of Bromodeoxyuridine Produce
Age-Dependent Morphological and Behavioral Abnormalities
Bryan
Kolb,
Brian
Pedersen,
Mark
Ballermann,
Robbin
Gibb, and
Ian Q.
Whishaw
Department of Psychology and Neuroscience, University of
Lethbridge, Lethbridge, Canada T1K 3M4
The mitotic marker 5-bromodeoxyuridine (BrdU) was injected twice
daily (60 mg/kg) into pregnant hooded rats on one of embryonic days (E)
11, 12, 13, 15, 17, or 21, or into rat pups on postnatal day (P) 10. The principal findings were the following: (1) BrdU exposure on E11
produces profound effects on body morphology, and animals must be fed a
special diet because of chronic tooth abnormalities; (2) BrdU exposure
at E17 or earlier produces a change in coat spotting pattern, the
precise pattern varying with age; (3) BrdU exposure on E15 or earlier
produces a reduction in both brain and body weight; (4) BrdU exposure
on E17 or earlier reduces cortical thickness; (5) BrdU exposure on
E11-E13 and at P10 reduces cerebellar size relative to cerebral size;
(6) spatial learning is significantly affected after injections of BrdU
at E11-E17, but the largest effect is on E17; (7) the deficit in spatial learning may be related in part to a reduction in visual acuity; and (8) skilled forelimb ability is most disrupted after BrdU
exposure at E15 but is also impaired after injections on E13 or
earlier. BrdU thus has teratological effects on body, brain, and
behavior that vary with the developmental age of the fetus or infant.
Key words:
bromodeoxyuridine; cerebral cortex; spatial learning; visual acuity; cerebellum; teratology
Copyright © 1999 Society for Neuroscience 0270-6474/99/1962337-10$05.00/0