RESUMO
Acid sphingomyelinase (A-SMase) and its reaction product ceramide may play a role in the pathophysiology of depressive disorders and in the therapeutic action of antidepressive drugs. In a prospective case-control study, A-SMase activity was measured in peripheral blood mononuclear cells of 17 patients with a major depressive episode who were free of antidepressant drug therapy for at least 10 days and 8 healthy volunteers. In the patient group, A-SMase activity was correlated to the score (n=17, r=0.64, P=0.005). The patient group exhibited higher A-SMase activity compared to healthy volunteers (T=2.09, df=21.33, P<0.05). In addition, we demonstrate that the antidepressants imipramine and amitriptyline induce a long-term reduction of the activity of A-SMase in cultured cells.
Assuntos
Química Encefálica/fisiologia , Encéfalo/enzimologia , Transtorno Depressivo Maior/enzimologia , Esfingomielina Fosfodiesterase/sangue , Regulação para Cima/fisiologia , Adulto , Antidepressivos Tricíclicos/farmacologia , Encéfalo/fisiopatologia , Química Encefálica/efeitos dos fármacos , Estudos de Casos e Controles , Células Cultivadas , Ceramidas/metabolismo , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/diagnóstico , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Feminino , Humanos , Masculino , Microdomínios da Membrana/efeitos dos fármacos , Microdomínios da Membrana/metabolismo , Pessoa de Meia-Idade , Bainha de Mielina/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estudos Prospectivos , Agregação de Receptores/efeitos dos fármacos , Agregação de Receptores/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Esfingomielina Fosfodiesterase/análise , Esfingomielinas/metabolismoRESUMO
Certain brain-computer interface (BCI) methods use intrinsic signals from the motor cortex to control neuroprosthetic devices. The organization of the motor pathways in those populations likely to use neuroprosthetic devices, therefore, needs to be determined; there is evidence that following disease or injury the representation of the body in the motor cortex may change. In this study, functional MRI measures of somatotopy following spinal cord injury (SCI) showed evidence of changes in limb representations in the motor cortex. Subjects with chronic SCI had unusual cortical patterns of activity when attempting to move limbs below their injury; amputees showed a more normal somatotopy. The functional reorganization may affect optimal implanted electrode placements for invasive BCI methods for these different populations.