Attenuation of BLA activity restores DA neuron activity after
long-term abstinence from cocaine
The DA system is regulated by an inhibitory circuit including the BLA
(Belujon et al., 2016; Belujon and Grace, 2017), and amygdala-driven
attenuation of DA neuron activity has been described after withdrawal
from acute amphetamine (Belujon et al., 2016). Thus, we then tested
whether DA neuron population activity could be restored by attenuating
BLA activity by local infusion of the sodium channel blocker TTX (or
vehicle), immediately before VTA recordings. A representative example of
placement of the infusion cannula is presented figure 4A, and the
location of the vehicle and TTX infusion cannula is presented figure 4B.
As expected, cocaine rats infused with vehicle (VEH) after 26-45 days
abstinence had fewer spontaneously active DA neurons, in comparison to
after inactivation of BLA activity with TTX (Figure 4C left). No
differences in the mean firing rate (figure 4C middle) or the percentage
of spikes in a burst (figure 4C right) were observed.