title: Water maze learning and forebrain mRNA expression of the neural cell adhesion molecule L1.
abstract: L1 and NCAM, two cell adhesion molecules of the immunoglobulin superfamily, have been implicated in the formation of neural circuits, synaptic plasticity, and cognitive function. In this study, we sought to investigate whether differences in the steady-state levels of L1 and NCAM expression in specific brain regions could account for individual differences in learning abilities. Using adult male Wistar rats, we evaluated mRNA levels of L1, NCAM, and the NCAM180 isoform in different brain regions (hippocampus, thalamus, striatum, prefrontal and frontal cortices) immediately after submitting rats to a massed training protocol in the water maze. The results showed that untrained and trained rats exhibited similar levels of mRNA for these molecules, which supports the view that training did not influence their immediate level of expression. However, in most of the brain regions we investigated (with the exception of prefrontal and frontal cortices), L1 mRNA levels were positively correlated with the latency to find the hidden platform in the water maze task and with posttraining plasma corticosterone levels. However, no correlations were observed for total NCAM or NCAM180 mRNA in the brain regions examined in this study. Given that animals with a slower spatial acquisition curve exhibited more anxiety-like responses, including thigmotactic behavior in the water maze and increased corticosterone levels, and that recent genetic studies indicate a role for L1 in anxiety, the current findings suggest a relationship among L1, anxiety, and cognitive processes.
authors.affiliation: Department of Psychobiology, Universidad Nacional de Educación a Distancia, Madrid, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Venero
authors.affiliation: Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tilling
authors.affiliation: Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany.
authors.forename: Irm
authors.initials: I
authors.lastname: Hermans-Borgmeyer
authors.affiliation: Department of Psychobiology, Universidad Nacional de Educación a Distancia, Madrid, Spain.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Herrero
authors.affiliation: Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany.
authors.forename: Melitta
authors.initials: M
authors.lastname: Schachner
authors.affiliation: Department of Psychobiology, Universidad Nacional de Educación a Distancia, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sandi
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism; D003071:Cognition / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D015870:Gene Expression / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics*; D019006:Neural Cell Adhesion Molecules / Q000235:genetics*; D009434:Neural Pathways / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology; D013315:Stress, Psychological / Q000378:metabolism
chemical_list: D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D020033:Protein Isoforms; D012333:RNA, Messenger; D003345:Corticosterone