title: Selective cholinergic denervation inhibits expression of long-term potentiation in the adult but not infant rat hippocampus.
abstract: The present study assessed the role of the cholinergic systems on the expression of perforant path long-term potentiation (LTP) in rat hippocampal slices from the infant and adult brain. To denervate the cholinergic systems, 192 IgG--saporin was injected into the lateral ventricle of the infant (2-weeks-old) and adult (6-weeks-old) rat brain. There, choline acetyltransferase-immunoreactive fibers were barely detectable 2 weeks and 2 months after injection for both the groups. For the infant rats, perforant path LTP was not affected by selective cholinergic denervation; the probability of LTP development was 0.83 (five out of six slices) and 0.78 (seven out of nine slices) at 2 weeks and 2 months later in 192 IgG--saporin-treated slices, as compared with 0.83 at each period in control saline-treated slices. In contrast, the expression of the LTP was blocked by selective cholinergic denervation for the adult rats; the probability of LTP development was 0 (zero out of 10 slices) and 0.38 (three out of eight slices) at 2 weeks and 2 months later in 192 IgG--saporin-treated slices, as compared with 0.8 (eight out of 10 slices) and 0.83 (five out of six slices) at each period in control saline-treated slices. The results of the present study thus suggest that the cholinergic systems play a crucial role in the expression of LTP in the adult brain and that the denervated systems in the infant brain could be compensated by the sprouting of non-cholinergic fibers.
authors.affiliation: Department of Neurosurgery, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Motooka
authors.forename: T
authors.initials: T
authors.lastname: Kondoh
authors.forename: T
authors.initials: T
authors.lastname: Nomura
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: H
authors.initials: H
authors.lastname: Tozaki
authors.forename: T
authors.initials: T
authors.lastname: Kanno
authors.forename: T
authors.initials: T
authors.lastname: Nishizaki
mesh_terms: D000367:Age Factors; D000818:Animals; D000911:Antibodies, Monoclonal; D002795:Choline O-Acetyltransferase / Q000032:analysis; D018678:Cholinergic Agents; D002799:Cholinergic Fibers / Q000201:enzymology; D003714:Denervation; D004594:Electrophysiology; D006624:Hippocampus / Q000166:cytology* / Q000254:growth & development* / Q000502:physiology; D000922:Immunotoxins; D007276:Injections, Intraventricular; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D009699:N-Glycosyl Hydrolases; D019580:Perforant Pathway / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins
chemical_list: C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D000922:Immunotoxins; D054789:Ribosome Inactivating Proteins, Type 1; D002795:Choline O-Acetyltransferase; D009699:N-Glycosyl Hydrolases; D000076985:Saporins