Wednesday, November 01, 2006

How emotions modulate memory through the amygdala

Transmission of sensory information through the rhinal cortices is essential for hippocampus-dependent learning. In Nature Neuroscience Quirk & Vidal-Gonzalez provide a nice summary of work by Paz. et. al. showing that amygdala activity elicited by an unexpected reward facilitates communication from perirhinal to entorhinal cortex, providing a physiological mechanism for emotional modulation of memory.

Figure: The amygdala enhances transfer of sensory information.
Sensory input flows from the neocortex to the hippocampus via the rhinal cortices (descending arrows). The hippocampus in turn assists in consolidating and storing this information through projections back to neocortex (ascending arrows). (a) During spontaneous activity, with low amygdala firing rates (blue traces on left), transfer of information from perirhinal cortex (Prh) to entorhinal cortex (Ent) is minimal (thin red arrows). (b) Following reward, the amygdala increases its firing rate and synchrony. This enables the transfer of sensory information through the rhinal cortices into the hippocampus (large red arrow).


  1. Anonymous6:38 PM

    What is the significance of this? Thanks. KKG

  2. I should have given more context with this post. It has been known for some time that memory of an event is enhanced if that event was accompanied by strong positive or negative emotions. This post was describing efforts to show how and where in the brain that enhancement takes place.