- Excessive activation of serotonin (5-HT) 1B receptors disrupts the formation of sensory maps in monoamine oxidase a and 5-ht transporter knock-out mice. Salichon, N., Gaspar, P., Upton, A.L., Picaud, S., Hanoun, N., Hamon, M., De Maeyer , E., Murphy, D.L., Mossner, R., Lesch, K.P., Hen, R., Seif, I. J. Neurosci. (2001)