Assuntos
Hipocampo/fisiologia , Rede Nervosa/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Processamento de Proteína Pós-Traducional/genética , Sequência de Aminoácidos , Animais , Proteínas Arqueais/biossíntese , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Linhagem Celular , Células Cultivadas , Citomegalovirus/química , Citomegalovirus/genética , Dependovirus/química , Dependovirus/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Regulação Viral da Expressão Gênica/fisiologia , Hipocampo/metabolismo , Hipocampo/microbiologia , Hipocampo/virologia , Humanos , Camundongos , Dados de Sequência Molecular , Rede Nervosa/metabolismo , Rede Nervosa/microbiologia , Rede Nervosa/virologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neurônios/microbiologia , Neurônios/virologia , Ratos , Proteínas Virais/biossíntese , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
OBJECTIVE: Increased acoustic noise (AN) during working memory leads to increased brain activation in healthy individuals and may have greater impact in human immunodeficiency virus (HIV) patients. RESULTS: Compared with control subjects, HIV patients showed reduced AN activation and lower neuronal marker N-acetylaspartate in prefrontal and parietal cortices. Competing use of the working memory network between AN and cognitive load showed lower dynamic range of the hemodynamic responses in prefrontal and parietal cortices in HIV patients. INTERPRETATION: These findings suggest that reduced reserve capacity of the working memory network in HIV patients and additional stress (eg, AN) might exhaust the impaired network for more demanding tasks.
Assuntos
Acústica , Infecções por HIV/fisiopatologia , HIV/fisiologia , Rede Nervosa/fisiopatologia , Rede Nervosa/virologia , Estimulação Acústica/métodos , Adulto , Mapeamento Encefálico , HIV/patogenicidade , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Oxigênio/sangue , Lobo Parietal/irrigação sanguínea , Lobo Parietal/fisiopatologia , Lobo Parietal/virologiaRESUMO
Human immunodeficiency virus (HIV)-positive patients commonly have attention and concentration problems. However, it remains unclear how HIV infection affects the attention network. Therefore, blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) was performed in 36 subjects (18 HIV and 18 seronegative [SN] controls) during a set of visual attention tasks with increasing levels of attentional load. Compared with SN controls, HIV subjects showed similar task performance (accuracies and reaction times) but decreased activation in the normal visual attention network (dorsal parietal, bilateral prefrontal, and cerebellar regions) and increased activation in adjacent or contralateral brain regions. Cognitive performance (assessed with NPZ-8), CD4, and viral load all correlated with activated BOLD signals in brain regions that activated more in HIV subjects. Furthermore, HIV subjects activated more than SN controls in brain regions that showed load-dependent increase in activation (right prefrontal and right parietal regions) but less in regions that showed a saturation effect with increasing load. These findings suggest that HIV-associated brain injury leads to reduced efficiency in the normal attention network, thus requiring reorganization and increased usage of neural reserves to maintain performance during attention-requiring tasks. Exceeding the brain reserve capacity may lead to attention deficits and cognitive impairment in HIV patients.