title: Growth hormone (GH) increases cognition and expression of ionotropic glutamate receptors (AMPA and NMDA) in transgenic zebrafish (Danio rerio).
abstract: The growth hormone/insulin-like factor I (GH/IGF-I) somatotropic axis is responsible for somatic growth in vertebrates, and has important functions in the nervous system. Among these, learning and memory functions related to the neural expression of ionotropic glutamate receptors, mainly types AMPA (α-amino-3hydroxy-5methylisoxazole-4propionic) and NMDA (N-methyl-d-aspartate) can be highlighted. Studies on these mechanisms have been almost exclusively conducted on mammal models, with little information available on fish. Consequently, this study aimed at evaluating the effects of the somatotropic axis on learning and memory of a GH-transgenic zebrafish (Danio rerio) model (F0104 strain). Long-term memory (LTM) was tested in an inhibitory avoidance apparatus, and brain expression of igf-I and genes that code for the main subunits of the AMPA and NMDA receptors were evaluated. Results showed a significant increase in LTM for transgenic fish. Transgenic animals also showed a generalized pattern of increase in the expression of AMPA and NMDA genes, as well as a three-fold induction in igf-I expression in the brain. When analyzed together, these results indicate that GH, mediated by IGF-I, has important effects on the brain, with improvement in LTM as a result of increased glutamate receptors. The transgenic strain F0104 was shown to be an interesting model for elucidating the intricate mechanisms related to the effect of the somatotropic axis on learning and memory in vertebrates.
authors.affiliation: Laboratório de Biologia Molecular, Instituto de Ciências Biológicas,Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil.
authors.forename: Ana Lupe Motta
authors.initials: AL
authors.lastname: Studzinski
authors.affiliation: Laboratório de Neurociências, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil.
authors.forename: Daniela Martí
authors.initials: DM
authors.lastname: Barros
authors.affiliation: Laboratório de Biologia Molecular, Instituto de Ciências Biológicas,Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil. Electronic address: dqmluf@furg.br.
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Marins
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001362:Avoidance Learning / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D003071:Cognition / Q000502:physiology*; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism*; D007266:Inhibition, Psychological; D057567:Memory, Long-Term / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013002:Somatomedins / Q000378:metabolism; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D013002:Somatomedins; D029961:Zebrafish Proteins; C431139:igf1 protein, zebrafish; D049452:Green Fluorescent Proteins; D013006:Growth Hormone
keywords: F0104 strain; Growth hormone overexpression; Inhibitory avoidance; Insulin-like growth factor I; Ionotropic receptors; Long-term memory