Serotonergic modulation of hippocampal acetylcholine release after long-term neuronal grafting.
Adult female rats sustained aspirative fimbria-fornix lesions and, 2 weeks later, received intrahippocampal grafts of fetal septal or mixed septal-raphe cell suspensions. Twenty-four months later, the extracellular concentration of hippocampal acetylcholine (ACh) was determined by microdialysis. Basal ACh levels (5-65 fmol/5 microl sham-operated rats) were strongly reduced after lesioning (3-7 fmol/5 microl). In septally transplanted and septal-raphe co-transplanted rats, hippocampal ACh concentrations were restored to near-normal levels (15-25 fmol/5 microl), indicating long-term functional survival of hippocampal transplants. After administration of citalopram (100 microM by infusion) and fenfluramine (20 mg/kg i.p.), the hippocampal ACh efflux was increased by 2- to 3-fold in all groups of rats. The relative increase of ACh was highest in co-transplanted rats, an effect which was possibly due to functional interactions between grafted raphe and septal neurons.
Hilgert
M
M
Department of Pharmacology, University of Mainz, Germany.
Buchholzer
M
M
Jeltsch
H
H
Kelche
C
C
Cassel
J C
JC
Klein
J
J
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D016380:Brain Tissue Transplantation; D002799:Cholinergic Fibers / Q000378:metabolism*; D005333:Fetus; D020712:Fornix, Brain / Q000378:metabolism / Q000601:surgery; D006085:Graft Survival / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism* / Q000601:surgery; D009473:Neuronal Plasticity / Q000502:physiology*; D011903:Raphe Nuclei / Q000378:metabolism / Q000601:surgery; D051381:Rats; D020318:Rats, Long-Evans; D012686:Septal Nuclei / Q000378:metabolism / Q000637:transplantation; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors
D012701:Serotonin; D000109:Acetylcholine