RESUMO
Text messaging is a popular means of communication among young adults. Consequently, this mode of communication may be used to positively influence students in their academic studies. In this study, students were given the opportunity to receive text or e-mail messages regarding lecture content. Short message reminders, in the form of texts or e-mails, were used to send bite-sized course content to undergraduate nursing students. Messages included questions that would be answered in the next day's lecture or reiterated a main point presented in the previous day's lecture. Following a survey at the end of the course, text users responded positively toward this pedagogical approach and felt the use of text messaging enhanced their learning experience. E-mail users reported a short message reminder was moderately useful to their study of anatomy. These results suggest text messaging may be a valuable tool for educators as they seek to incorporate technology into the classroom.
Assuntos
Telefone Celular , Correspondência como Assunto , Educação em Enfermagem/métodos , Sistemas de Alerta , Anatomia/educação , Correio Eletrônico , Humanos , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Estados UnidosRESUMO
Glial cell-line derived neurotrophic factor (GDNF) has demonstrated robust effects on dopamine (DA) neuron function and survival. A post-translational processing model of the human GDNF proprotein theorizes the formation of smaller, amidated peptide(s) from the proregion that exhibit neurobiological function, including an 11-amino-acid peptide named dopamine neuron stimulating peptide-11 (DNSP-11). A single treatment of DNSP-11 was delivered to the substantia nigra in the rat to investigate effects on DA-neuron function. Four weeks after treatment, potassium (K+) and D-amphetamine evoked DA release were studied in the striatum using microdialysis. There were no significant changes in DA-release after DNSP-11 treatment determined by microdialysis. Dopamine release was further examined in discrete regions of the striatum using high-speed chronoamperometry at 1-, 2-, and 4-weeks after DNSP-11 treatment. Two weeks after DNSP-11 treatment, potassium-evoked DA release was increased in specific subregions of the striatum. However, spontaneous locomotor activity was unchanged by DNSP-11 treatment. In addition, we show that a single treatment of DNSP-11 in the MN9D dopaminergic neuronal cell line results in phosphorylation of ERK1/2, which suggests a novel cellular mechanism responsible for increases in DA function.
Assuntos
Dopamina/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/química , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Linhagem Celular/efeitos dos fármacos , Humanos , Técnicas In Vitro , Masculino , Atividade Motora/efeitos dos fármacos , Neurônios/metabolismo , Fragmentos de Peptídeos/química , Fosforilação/efeitos dos fármacos , Ratos Endogâmicos F344 , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Estriado Ventral/efeitos dos fármacos , Estriado Ventral/metabolismoRESUMO
Glial cell-line derived neurotrophic factor (GDNF) has been established as a growth factor for the survival and maintenance of dopamine (DA) neurons. In phase I clinical trials, GDNF treatment in Parkinson's disease patients led to improved motor function and GDNF has been found to be down regulated in Parkinson's disease patients. Studies using GDNF heterozygous (Gdnf(+/-)) mice have demonstrated that a partial reduction of GDNF leads to an age-related accelerated decline in nigrostriatal DA system- and motor-function and increased neuro-inflammation and oxidative stress in the substantia nigra (SN). Therefore, the purpose of the current studies was to determine if GDNF replacement restores motor function and functional markers within the nigrostriatal DA system in middle-aged Gdnf(+/-) mice. At 11months of age, male Gdnf(+/-) and wildtype (WT) mice underwent bilateral intra-striatal injections of GDNF (10µg) or vehicle. Locomotor activity was assessed weekly 1-4weeks after treatment. Four weeks after treatment, their brains were processed for analysis of GDNF levels and various DAergic and oxidative stress markers. An intrastriatal injection of GDNF increased motor activity in Gdnf(+/-) mice to levels comparable to WT mice (1week after injection) and this effect was maintained through the 4-week time point. This increase in locomotion was accompanied by a 40% increase in striatal GDNF protein levels and SN GDNF expression in Gdnf(+/-) mice. Additionally, GDNF treatment significantly increased the number of tyrosine hydroxylase (TH)-positive neurons in the SN of middle-aged Gdnf(+/-) mice, but not WT mice, which was coupled with reduced oxidative stress in the SN. These studies further support that long-term changes related to the dysfunction of the nigrostriatal pathway are influenced by GDNF expression and add that this dysfunction appears to be responsive to GDNF treatment. Additionally, these studies suggest that long-term GDNF depletion alters the biological and behavioral responses to GDNF treatment.
Assuntos
Fator Neurotrófico Derivado de Linhagem de Célula Glial/deficiência , Fator Neurotrófico Derivado de Linhagem de Célula Glial/farmacologia , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/patologia , Corpo Estriado/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Dopamina/fisiologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/fisiologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Substância Negra/fisiopatologia , Superóxido Dismutase/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Glial cell line-derived neurotrophic factor (GDNF) supports the viability of midbrain dopamine (DA) neurons that degenerate in Parkinson's disease. Middle-aged, 12 month old, Gdnf heterozygous (Gdnf(+/-)) mice have diminished spontaneous locomotor activity and enhanced synaptosomal DA uptake compared with wild type mice. In this study, dopamine transporter (DAT) function in middle-aged, 12 month old Gdnf(+/-) mice was more thoroughly investigated using in vivo electrochemistry. Gdnf(+/-) mice injected with the DAT inhibitor, nomifensine, exhibited significantly more locomotor activity than wild type mice. In vivo electrochemistry with carbon fiber microelectrodes demonstrated enhanced clearance of DA in the striatum of Gdnf(+/-) mice, suggesting greater surface expression of DAT than in wild type littermates. Additionally, 12 month old Gdnf(+/-) mice expressed greater D(2) receptor mRNA and protein in the striatum than wild type mice. Neurochemical analyses of striatal tissue samples indicated significant reductions in DA and a faster DA metabolic rate in Gdnf(+/-) mice than in wild type mice. Altogether, these data support an important role for GDNF in the regulation of uptake, synthesis, and metabolism of DA during aging.