ABSTRACT
In the version of this article initially published, Fig. 7f purported to show an example of a multi-synapse spine. However, the structure in question included a mitochondrion and microtubules, meaning that it was actually a segment of dendritic shaft. A new image showing an example of a bona fide spine has been substituted. The legend has been changed to state that the image shows two boutons rather than three. The error has been corrected in the HTML and PDF versions of the article. The original and corrected figures are shown in the accompanying Author Correction.
ABSTRACT
Neural circuits underlying auditory fear conditioning have been extensively studied. Here we identified a previously unexplored pathway from the lateral amygdala (LA) to the auditory cortex (ACx) and found that selective silencing of this pathway using chemo- and optogenetic approaches impaired fear memory retrieval. Dual-color in vivo two-photon imaging of mouse ACx showed pathway-specific increases in the formation of LA axon boutons, dendritic spines of ACx layer 5 pyramidal cells, and putative LA-ACx synaptic pairs after auditory fear conditioning. Furthermore, joint imaging of pre- and postsynaptic structures showed that essentially all new synaptic contacts were made by adding new partners to existing synaptic elements. Together, these findings identify an amygdalocortical projection that is important to fear memory expression and is selectively modified by associative fear learning, and unravel a distinct architectural rule for synapse formation in the adult brain.
