There is a growing interest in how pro-inflammatory cytokines modulate cognitive processes, especially since these molecules do not affect every brain area in a uniform way. The tumor necrosis factor alpha (TNF-alpha) for example exerts neuroprotective and neurodegenerative effects, depending on brain region. While some research suggests enhancing effects of the TNF-alpha gene (TNF-alpha -308G/A) on cognitive function, further research is needed to clarify the association between the TNF-alpha gene and specific areas of cognitive performance including their neurophysiological correlates. In this study we examined associations of the TNF-alpha -308G/A single nucleotide polymorphism (rs1800629) with attention and mental rotation performance in an event-related potential (ERP) study. The results show that carriers of the -308 A allele display elevated attentional processes (i.e. a stronger N1) as compared to the GG genotype group. Mental rotation performance varied across genotypes only when demands on mental rotation were high. Here, carriers of the -308 A allele performed better than the GG genotype group. This is paralleled by the neurophysiological data. The finding of enhanced attentional and mental rotation performance in A allele carriers supports recent findings that the A allele of this single nucleotide polymorphism (SNP) enhances cognitive performance on a general measure of cognitive processing speed.

Beste, C., Heil, M., Domschke, K., Baune, B.T., Konrad, C. (2010). Associations between the tumor necrosis factor alpha gene (-308G->A) and event-related potential indices of attention and mental rotation. Neuroscience, 170, 742-748.