BACKGROUND The idea that memory is stored as enduring changes in the brain dates
back at least to the time of Plato and Aristotle (circa 350 BCE), but its scientific articulation …

Tremendous strides have been made in our understanding of the neurobiological substrates
of memory–the so-called memory “engram”. Here, we integrate recent progress in the …

Modern optogenetics can be tuned to evoke activity that corresponds to naturally occurring
local or global activity in timing, magnitude or individual-cell patterning. This outcome has …

The amygdala has long been associated with emotion and motivation, playing an essential
part in processing both fearful and rewarding environmental stimuli. How can a single …

The nucleus accumbens is a major input structure of the basal ganglia and integrates
information from cortical and limbic structures to mediate goal-directed behaviors. Chronic …

Many attempts have been made to localize the physical trace of a memory, or engram, in the
brain. However, until recently, engrams have remained largely elusive. In this Review, we …

The idea that memory is stored in the brain as physical alterations goes back at least as far
as Plato, but further conceptualization of this idea had to wait until the 20 th century when …

The predominant focus in the neurobiological study of memory has been on remembering
(persistence). However, recent studies have considered the neurobiology of forgetting …

Memory retrieval involves the interaction between external sensory or internally generated
cues and stored memory traces (or engrams) in a process termed 'ecphory'. While ecphory …

Highlights•We review the history of research into putative memory storage mechanisms.•We
highlight recent advances catalyzed by memory engram labeling technology.•We discuss …