Modulation of memory consolidation by the basolateral amygdala or nucleus accumbens shell requires concurrent dopamine receptor activation in both brain regions

Abstract

Previous findings indicate that the basolateral amygdala (BLA) and the nucleus accumbens (NAc) interact in influencing memory consolidation. The current study investigated whether this interaction requires concurrent dopamine (DA) receptor activation in both brain regions. Unilateral, right-side cannulae were implanted into the BLA and the ipsilateral NAc shell or core in male Sprague-Dawley rats (∼300 g). One week later, the rats were trained on an inhibitory avoidance (IA) task and, 48 h later, they were tested for retention. Drugs were infused into the BLA and NAc shell or core immediately after training. Post-training intra-BLA infusions of DA enhanced retention, as assessed by latencies to enter the shock compartment on the retention test. Infusions of the general DA receptor antagonist cis-Flupenthixol (Flu) into the NAc shell (but not the core) blocked the memory enhancement induced by the BLA infusions of DA. In the reverse experiment, post-training intra-NAc shell infusions of DA enhanced retention and Flu infusions into the BLA blocked the enhancement. These findings indicate that BLA modulation of memory consolidation requires concurrent DA receptor activation in the NAc shell but not the core. Similarly, NAc shell modulation of memory consolidation requires concurrent DA receptor activation in the BLA. Together with previous findings, these results suggest that the dopaminergic innervation of the BLA and NAc shell is critically involved in the modulation of memory consolidation.

Dual Role of Medial A10 Dopamine Neurons in Affective Encoding

“…Studies have shown that post-training injections of dopamine receptor agonists and antagonists into the nucleus accumbens, respectively, facilitate and disrupt associative learning involving both positive and negative incentive stimuli (Setlow and McGaugh, 1998;Dalley et al, 2005;LaLumiere et al, 2005). Our data suggest that rats can learn conditioned place aversion under severe inhibition of medial A10 neurons, bringing into question the idea that dopamine, at least in the terminal regions of these neurons, is required for or facilitates learning per se.…”

Basolateral amygdala projections to ventral hippocampus modulate the consolidation of footshock, but not contextual, learning in rats

“…Prior studies indicate that the BLA modulates the consolidation for many different types of learning including inhibitory avoidance (LaLumiere et al 2004(LaLumiere et al , 2005, CFC Huff and Rudy 2004), conditioned taste aversion (Miranda et al 2003;Guzman-Ramos and Bermudez-Rattoni 2012), spatial and cued-response learning (Packard et al 1994), and novel object recognition (Roozendaal et al 2008;Bass et al 2012). However, evidence also indicates that different types or kinds of learning involve separate and distinct brain regions, as, for example, the hippocampus and caudate are involved in the consolidation of spatial and cued water maze learning, respectively (Packard et al 1994).…”

Impairment in Consolidation of Learned Place Preference Following Dopaminergic Neurotoxicity in Mice is Ameliorated by N-acetylcysteine but not D1 and D2 Dopamine Receptor Agonists

“…The findings that DA is also involved in aversive conditioning by LiCl (Di Chiara, 2002) and fear conditioning (Nader and LeDoux, 1999;Pezze and Feldon, 2004) support its role in associative learning and memory consolidation. Blockade of D1-like and D2-like DA receptors interferes with consolidation of Pavlovian conditioned behavior (Greba et al, 2001;Koch et al, 2000;LaLumiere et al, 2005;Nader and LeDoux, 1999). Given that METH neurotoxicity diminishes levels of corticostriatal and mesolimbic DA, we first sought to investigate if posttraining administration of D1 and D2 DA receptor agonist improves consolidation of cocaine CPP.…”