After binding to the neurokinin-1 (NK-1) receptor, SP regulates many pathophysiological functions in the central nervous system, such as emotional behavior, stress, depression, anxiety, emesis, vomiting, migraine, alcohol addiction, seizures and neurodegeneration.
Genetic deletion or antagonism of the neurokinin 1 receptor (NK1R) decreases alcohol intake, alcohol reward, and stress-induced alcohol relapse in rodents, while TACR1 variation is associated with alcoholism in humans.
Each of the 5 SNPs in the TACR1 gene that was significantly related to AD severity in the SAGE data set and/or the BOLD response to the craving task is near the 3' or 5' areas of the gene and may therefore be near mutations with potential functional significance.
Four single-nucleotide polymorphisms (rs3771829, rs3771833, rs3771856, and rs1701137) at the TACR1 gene, previously known to be associated with bipolar disorder or alcoholism, were strongly associated with ADHD.