title: Pentyl-4-yn-valproic acid enhances both spatial and avoidance learning, and attenuates age-related NCAM-mediated neuroplastic decline within the rat medial temporal lobe.
abstract: 2-N-Pentyl-4-pentynoic acid [pentyl-4-yn-valproic acid (VPA)] is an analogue of valproic acid that induces neuritogenesis and increases neural cell adhesion molecule (NCAM) prevalence in cultured neural cells. As memory consolidation involves synapse growth, aided by cell adhesion molecule function, we determined whether or not pentyl-4-yn-VPA had cognition-enhancing properties. Pentyl-4-yn-VPA (16-85 mg/kg) significantly improved water maze learning and task retention when given prior to each training session. Acute administration of pentyl-4-yn-VPA also influenced memory consolidation processes as, when given at 3 h post-passive avoidance training, the amnesia induced by scopolamine given 6 h post-training was prevented in a dose-dependent manner. Chronic administration of pentyl-4-yn-VPA (16.8 or 50.4 mg/kg) also significantly reduced escape latencies in the water maze task, 24 h following the last drug administration. This improved spatial learning was accompanied by enhanced neuroplasticity as the expression of NCAM polysialylated neurons in the infragranular zone of the dentate gyrus and in layer II of the perirhinal and piriform cortex was increased significantly following chronic drug treatment. The cognition-enhancing qualities of pentyl-4-yn-VPA, combined with its ability to attenuate the age-related loss of the NCAM polysialylation state, suggest that it may effectively slow the onset of cognitive decline.
authors.affiliation: Department of Pharmacology, The Conway Institute, University College Dublin, Dublin, Ireland.
authors.forename: K J
authors.initials: KJ
authors.lastname: Murphy
authors.forename: G B
authors.initials: GB
authors.lastname: Fox
authors.forename: A G
authors.initials: AG
authors.lastname: Foley
authors.forename: H C
authors.initials: HC
authors.lastname: Gallagher
authors.forename: A
authors.initials: A
authors.lastname: O'Connell
authors.forename: A M
authors.initials: AM
authors.lastname: Griffin
authors.forename: H
authors.initials: H
authors.lastname: Nau
authors.forename: C M
authors.initials: CM
authors.lastname: Regan
mesh_terms: D000375:Aging; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002460:Cell Line; D006339:Heart Rate / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007668:Kidney / Q000033:anatomy & histology / Q000187:drug effects; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects; D008168:Lung / Q000033:anatomy & histology / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D019006:Neural Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D011485:Protein Binding; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000494:pharmacology; D013702:Temporal Lobe / Q000187:drug effects* / Q000378:metabolism; D014635:Valproic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D018727:Muscarinic Antagonists; D019006:Neural Cell Adhesion Molecules; C434604:pentyl-4-yn-valproic acid; D014635:Valproic Acid; D012601:Scopolamine