Alzheimer Disease and Human Consciousness: A Neurogenetic Connection

Alzheimer disease (AD) is a neurodegenerative disorder that slowly erodes some of the facets of human consciousness. During the pathological course of AD, beta-amyloid plaques form whichcauses damage to neurons and results in the gross loss of brain volume. As a consequence of AD, the afflicted individual develops decreases in cognitive/executive function, memory impairment/loss, and the inability to inhibit inappropriate behaviors. Another way of saying this is that the afflicted individual ceases to be the person whom they once were, i.e., their modalities of consciousness has deteriorated. Mutations in several genes, e.g., the gene variant APOE-epsilon4, APP, PSEN1, PSEN2, and TREM2 have all been correlated with the increased incidence and more rapid progression of AD. This has given support to the proposal that there are neurogenetic correlates of consciousness (NgCC). In previous works, these NgCC have been delineated into three neurogenetic phases of human consciousness. AD is a primary example of gene-based neurodegeneration that can take place in the third neurogenetic phase. There is hope that symptoms of AD may be reversed with the development of novel genetic therapies. Some gene therapies are underway, e.g., FGF2, leptin, and NEU1 with the aim of reversing AD symptomatology. If these gene therapies are one day successful in reversing some of the symptoms of AD, can they eventually be used to enhance human consciousness in individuals without AD?