Quantitative distribution of AChE-positive neurons in the hippocampus of young and aged rats.
Acetylcholinesterase (AChE)-positive neurons were counted in the different layers of the rostral (septal) third, the middle third and the caudal (temporal) third of the hippocampus from 3 month (young) and 27 month old rats (aged) using AChE stained cryostat sections. The rats were treated with 3 and 2.5 mg of diisopropylphosphofluoridate/kg body weight, respectively 3 h before sacrifice. The study showed -1) a high numerical density of AChE-positive neurons (10.9 to 18.9 perikarya/mm2) in the hilus (fascia dentata), the str. oriens/pyramidale of CA1 and the subiculum, a particularly low density (less than 0.1 perikarya/mm2) in the str. granulosum and moleculare of the dentate area; -2) a significant (p less than 0.05) linear increase of the numerical density in most of the hippocampal layers from the rostral to the caudal pole; -3) no significant differences between young and aged animals; - and 4) a higher sensitivity to DFP-treatment in aged than in young animals. The distribution of AChE-positive neurons corresponds with the distribution of somatostatin-immunoreactive neurons described in the literature. A modulatory effect on neurotransmission is discussed as a possible function of the AChE in peptidergic neurons.
Department of Anatomy, University of Würzburg, Federal Republic of Germany.
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Zenner
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Kugler
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Schiebler
D000110:Acetylcholinesterase / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000166:cytology / Q000201:enzymology*; D006651:Histocytochemistry; D007531:Isoflurophate; D008297:Male; D009474:Neurons / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
D007531:Isoflurophate; D000110:Acetylcholinesterase