Late postnatal growth in the dentate area of the rat hippocampus compensates for volumetric changes caused by early postnatal toluene exposure.
The present report assesses the reversibility of previously described quantitative morphological alterations in the dentate area of the hippocampi of rats exposed to 500 ppm toluene for 12 h daily from postnatal day 1 (P1) to P28. Following the exposure, rats were allowed to survive until P120. The volumes of hippocampal components, as they appear in Timm-stained histological sections, were determined using the Cavalieri estimator. At P120, no differences were apparent in the volumes of the dentate components of control and experimental animals. The differences observed immediately after exposure were eliminated by significantly larger increases in the sizes of early affected components in experimental animals. Different periods of neurogenesis in rodents and primates are briefly discussed as possible confounders of rodent models of permanent toluene-induced morphological alterations in primates.
Slomianka
L
L
Stereological Research Laboratory, University of Aarhus, Denmark.
Rungby
J
J
Edelfors
S
S
Ravn-Jonsen
A
A
D000818:Animals; D000831:Animals, Newborn; D006624:Hippocampus / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014050:Toluene / Q000008:administration & dosage / Q000633:toxicity*
D014050:Toluene