RESUMO
The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a psychophysiological index of effort allocation (motivation): The less effort the subject allocates, the greater the 0.10-Hz component. Results indicated that, compared to controls, ADHD subjects had a greater 0.10-Hz component, which was associated with poor test performance over time. Thus, using a psychophysiological measure, we were able to confirm the clinical concept of ADHD from a motivational perspective.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Frequência Cardíaca/fisiologia , Atenção/fisiologia , Criança , Feminino , Humanos , Masculino , Motivação , PsicometriaRESUMO
The total number of immunocytochemically identified vasopressin (AVP) cells was determined morphometrically in the paraventricular (PVN) and dorsolateral part of the supraoptic nucleus (dl-SON) of the human hypothalamus in 30 subjects ranging in age from 15 to 97 years, including 10 Alzheimer's disease (AD) patients. The aim of the present study was to test the hypothesis that the increased activity of AVP neurons reported earlier is accompanied by an absence of cell loss in these nuclei in senescence and AD. The results show that numbers of immunoreactive AVP cells in the PVN and dl-SON do not decline during aging or in AD. During aging, the number of neurons expressing AVP even increased in the PVN of control subjects. The nuclear diameter of the AVP cells in the PVN and dl-SON showed an increase in old AD patients. It is concluded that no cell loss occurs in the AVP cell population in the PVN and dl-SON during aging and in AD, and that AVP expression increases in the PVN during normal aging, but not in AD.
Assuntos
Envelhecimento/patologia , Doença de Alzheimer/patologia , Arginina Vasopressina/metabolismo , Núcleo Hipotalâmico Paraventricular/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Doença de Alzheimer/metabolismo , Reações Cruzadas , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neurônios/metabolismo , Núcleo Supraóptico/metabolismoRESUMO
Total cell numbers in the paraventricular nucleus (PVN) were previously shown to remain unaltered with aging and in AD. The aim of the present study was to determine the aging pattern of the oxytocin (OXT) cell population in the PVN. For this purpose, the number of immunocytochemically identified oxytocin cells was determined in the PVN of the human hypothalamus in 20 control subjects ranging in age from 15 to 90 years and in 10 Alzheimer's disease (AD) patients aged 46 to 97 years. The results show that the number of OXT cells in the PVN is similar in males and females and remains unaltered in senescence and AD. It is concluded that the remarkable stability of the PVN in these conditions also applies for the subpopulation of OXT cells in this nucleus and that reports in the literature on diminished OXT secretion in AD do not seem to be based on a decrease in the number of OXT expressing neurons from the PVN.
