- 5-HT1B receptor knockout, but not 5-HT1A receptor knockout mice, show reduced startle reactivity and footshock-induced sensitization, as measured with the acoustic startle response. Dirks, A., Pattij, T., Bouwknecht, J.A., Westphal, T.T., Hijzen, T.H., Groenink, L., van der Gugten, J., Oosting, R.S., Hen, R., Geyer, M.A., Olivier, B. Behav. Brain Res. (2001)









