Interacting brain systems modulate memory consolidation

Abstract

Emotional arousal influences the consolidation of long-term memory. This review discusses experimental approaches and relevant findings that provide the foundation for current understanding of coordinated interactions between arousal activated peripheral hormones and the brain processes that modulate memory formation. Rewarding or aversive experiences release the stress hormones epinephrine (adrenalin) and glucocorticoids from the adrenal glands into the bloodstream. The effect of these hormones on memory consolidation depends upon binding of norepinephrine to beta-adrenergic receptors in the basolateral complex of the amygdala (BLA). Much evidence indicates that the stress hormones influence release of norepinephrine in the BLA through peripheral actions on the vagus nerve which stimulates, through polysynaptic connections, cells of the locus coeruleus to release norepinephrine. The BLA influences memory storage by actions on synapses, distributed throughout the brain, that are engaged in sensory and cognitive processing at the time of amygdala activation. The implications of the activation of these stress-activated memory processes are discussed in relation to stress-related memory disorders.

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

“…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). The BLA interacts with a variety of structures both cortical (e.g., anterior cingulate cortex, insular cortex) and subcortical (e.g., caudate, nucleus accumbens) during memory consolidation, potentially accounting for its diffuse involvement in consolidation across tasks and types of memory (for recent review, see McIntyre et al 2012). However, prior work was unable to directly manipulate activity in distinct efferent BLA pathways to determine whether such pathways were selectively involved in specific kinds of memory consolidation.…”

“…However, work strongly indicates that the basolateral amygdala (BLA) modulates the consolidation of a wide array of memories. It has been hypothesized that the BLA plays this more general role, at least in part, through interactions with distinct regions (McGaugh 2002(McGaugh , 2004McIntyre et al 2012). BLA connections with forebrain regions such as the hippocampus and striatum that are selectively involved in the consolidation of certain kinds of memories (McDonald 1991;Pitkänen et al 2000;McGaugh 2002;Malin and McGaugh 2006;Paz et al 2006;Chavez et al 2013) suggest that efferent pathways from the BLA may be selectively involved in modulating consolidation for specific kinds of information.…”

Enhancing Rehabilitative Therapies with Vagus Nerve Stimulation

“…Other peripherally acting agents that conduct ascending information through the vagus nerve demonstrate a similar inverted-U response [4,5,[135][136][137][138]. The precise mechanisms that underlie this response profile are not understood, but several explanations could account for the inverted-U response.…”

The anterior medial temporal lobes: Their role in food intake and body weight regulation

“…Third, cued conditioning relies on the amygdala, but in the case of a conditioning relying on context, the hippocampus would additionally be recruited [97]. Fourth, a lot of studies have shown that a stimulation of the amygdala enhances hippocampal-dependent memory and modulates the synaptic plasticity in the hippocampus (e.g., [1,2,40,69,93,100,102,104]). Fifth, learning to suppress conditioned responses requires interactions between the hippocampus and the (basolateral) amygdala.…”