RESUMO
The effects of various doses (40 microg/kg/hr, 300 microg/kg/hr, 600 microg/kg/hr or placebo) of hydrocortisone on tasks assessing working and declarative memory function were measured in 4 groups of 10 young men. During the infusion, participants were given an item-recognition working memory task, a paired-associate declarative memory task, and a continuous performance task used to control possible concomitant effects of corticosteroids on vigilance. The results revealed significant acute effects of the highest dose of hydrocortisone on working memory function, without any significant effect on declarative memory function or arousal-vigilance performance. These results suggest that working memory is more sensitive than declarative memory to the acute elevations of corticosteroids, which could explain the detrimental effects of corticosteroids on acquisition and consolidation of information, as reported in the literature.
Assuntos
Anti-Inflamatórios/efeitos adversos , Nível de Alerta/efeitos dos fármacos , Hidrocortisona/efeitos adversos , Memória/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Hormônio Adrenocorticotrópico/sangue , Adulto , Análise de Variância , Glicemia/metabolismo , Relação Dose-Resposta a Droga , Humanos , Hidrocortisona/sangue , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Testes Neuropsicológicos , Testes de Associação de PalavrasRESUMO
Four neuropeptides (substance P, methionine-enkephalin, neurotensin and cholecystokinin) were measured by radioimmunoassays in a number of brain regions of deceased patients with mental illnesses and controls. The most striking finding in these studies was that methionine-enkephalin concentrations in caudate nuclei of chronic paranoid schizophrenic patients were reduced relative to several control groups. Neuroleptics had no obvious effects on any of the four measured neuropeptides. These findings are not inconsistent with the hypothesis that methionine-enkephalin may be involved in some of the pathology of the schizophrenic syndrome.