Transient reduction in hippocampal serotonergic innervation after neonatal parachloroamphetamine treatment.
This study examined the effects of parachloroamphetamine on neonatal forebrain serotonergic (5-HT) innervation. Rat pups were treated with PCA on P3 and P4. Significant reductions in 5-HT content were observed in the hippocampal formation, frontal cortex and entorhinal cortex on P5 and P7. By P14, neocortical 5-HT had returned to normal levels while hippocampal 5-HT values remained less than control. Hippocampal 5-HT content reached normal range by P21. High affinity 5-HT uptake in hippocampal synaptosomal preparations was similarly reduced on P5 and P7 suggesting that 5-HT terminals were being lesioned by PCA. 5-HT uptake recovered significantly by P14 perhaps reflecting the extraordinary plasticity of the 5-HT projections in the neonate. However, in contrast to the complete restoration of hippocampal 5-HT content, 5-HT uptake values remained significantly less than control. No change in 5-HT content was observed in either the hypothalamus or midbrain raphe at any age studied. Thus, the rapid onset of effects, regional selectivity and transient reduction of 5-HT levels recommend the use of PCA in studies of the role of 5-HT in hippocampal development.
Haring
J H
JH
Department of Anatomy and Neurobiology, St. Louis University Health Sciences Center, MO 63104.
Faber
K M
KM
Wilson
C C
CC
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D005625:Frontal Lobe / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012701:Serotonin / Q000378:metabolism*; D010133:p-Chloroamphetamine / Q000494:pharmacology*
D012701:Serotonin; D010133:p-Chloroamphetamine