Additionally, mice with complete 5-HT1A receptor knockout (KO), lacking both auto- and heteroreceptors through life, consistently showed increased anxiety in conflict-based anxiety paradigms tasks, while exhibiting decreased behavioral despair in response to stress (higher mobility time in the FST and TST), suggesting that the absence of 5-HT1A receptors could result in an “antidepressant-like” effect [14,106,107,108,109]. This evidence concerns the gene HTR1A and Anxiety.