Thus, albeit highly speculative, a decrease in TrkB activity in the striatum appears to “override” a decrease in the hippocampus, and knockdown in the dorsal striatum is required for an effect on anxiety-related behaviors, which are not altered by knockdown of the BDNF/TrkB system restricted to the nucleus accumbens, or to D1R or D2R MSNs. This evidence concerns the gene NTRK2 and Anxiety.