Activation of Endogenous Retrovirus, Brain Infections and Environmental Insults in Neurodegeneration and Alzheimer's Disease.

Chronic neurodegenerative diseases are complex, and their pathogenesis is uncertain. Alzheimer's disease (AD) is a neurodegenerative brain alteration that is responsible for most dementia cases in the elderly. AD etiology is still uncertain; however, chronic neuroinflammation is a constant component of brain pathology. Infections have been associated with several neurological diseases and viruses of the Herpes family appear to be a probable cause of AD neurodegenerative alterations. Several different factors may contribute to the AD clinical progression. Exogeneous viruses or other microbes and environmental pollutants may directly induce neurodegeneration by activating brain inflammation. In this paper, we suggest that exogeneous brain insults may also activate retrotransposons and silent human endogenous retroviruses (HERVs). The initial inflammation of small brain areas induced by virus infections or other brain insults may activate HERV dis-regulation that contributes to neurodegenerative mechanisms. Chronic HERV activation in turn may cause progressive neurodegeneration that thereafter merges in cognitive impairment and dementia in genetically susceptible people. Specific treatment for exogenous end endogenous pathogens and decreasing pollutant exposure may show beneficial effect in early intervention protocol to prevent the progression of cognitive deterioration in the elderly.

A behavioral protocol to assess the relationship between three cognitive biases and future depression severity.

According to the cognitive model of depression, memory bias, interpretation bias, and attention bias are associated with the development and maintenance of depression. Here, we present a protocol for investigating whether and how the novel coronavirus disease 2019 (COVID-19) pandemic may affect the relationship between current cognitive biases and future depression severity in a population with non-clinical depression. This protocol can also be used in other contexts, including cognitive bias-related studies and depression-related functional magnetic resonance imaging (fMRI) studies. For complete details on the use and execution of this protocol, please refer to Zhang et al. (2021).