Figure 6.

Prerestraint intra-BLA administration of the β-noradrenergic receptor antagonist, propranolol, blocked the decrease in VTA DA neuron population activity and reversed the attenuation of amphetamine-induced locomotor activity measured 24 h after restraint. a1, b1, Cannulae placements of all rats included in this study. a2–a4, For all rats restrained for a 2 h session, propranolol pretreatment (PRO; n = 9) significantly increased (a2) the DA neuron population activity than saline (SAL; n = 10) control (*p < 0.05), with no significant difference between (a3) mean firing rates or (a4) bursting activity. DA neurons recorded: SAL (n = 59), PRO (n = 86). b2, b3, AMPH induced higher locomotor activity regardless of pretreatment (b2, SAL; b3, PRO), with significantly higher locomotor activity in rats pretreated with PRO (all ps < 0.05). Group sizes: SAL-SAL (n = 7), SAL-AMPH (n = 8), PRO-SAL (n = 8), and PRO-AMPH (n = 8).