Estimation of neuronal numbers in rat hippocampus following neonatal amphetamine exposure: a stereology study.
In this study, the effects of amphetamine exposure during a portion of the brain growth spurt on the total number of hippocampal pyramidal cells (CA1/CA3 subregions) and the granule cells (dentate gyrus) were examined in both neonatal and adult rats. Intragastric intubation was used to administer 5, 15 or 25 mg/kg/day of amphetamine to Sprague-Dawley rat pups from PDs 4-9. Unbiased stereology was used to estimate the total number of cells present within each hippocampal subregion at both PD 9 and PD 68. The results indicated that neonatal amphetamine exposure did not alter the cell number, the reference volume or the density in any of the hippocampal subregions assessed, regardless of age. However, amphetamine significantly altered the rate of neuronal incorporation in both the hippocampal CA3 subregion and the dentate gyrus, and this effect appeared to be dose-related with the most robust effect observed in the highest amphetamine dose. While these findings did not demonstrate significant injurious effects of neonatal amphetamine treatment on the number of hippocampal neurons, these data suggest that amphetamine may interfere with proper hippocampal development. Future studies employing more sensitive measurements or exposing amphetamine during an alternate period of development may provide more information regarding amphetamine-mediated developmental neurotoxicity.
Smith
Andrew M
AM
Department of Neuroscience & Experimental Therapeutics, Texas A&M Health Science Center College of Medicine, College Station, TX 77843-1114, United States.
Pappalardo
Dana
D
Chen
Wei-Jung A
WJ
D000367:Age Factors; D000661:Amphetamine / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count / Q000379:methods; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013223:Statistics as Topic; D013238:Stereotaxic Techniques
D000697:Central Nervous System Stimulants; D000661:Amphetamine