It has been recently found that the depletion of 5-HT1A heteroreceptor in the dentate gyrus (DG) of the hippocampus by means of the local elevation of glucocorticoid levels; that is, a chronic stress mechanism, is associated with the development of stress-induced anxiety, demonstrating again the importance of the 5-HT1A receptor in the modulation of the neuronal activity [31]. This evidence concerns the gene HTR1A and Anxiety.