Do you remember the song that was playing during your first kiss? Both positive and negative emotions influence learning and memory but researchers have not determined the mechanism. Now Hu et al. report that the neurotransmitter norepinephrine regulates glutamate receptor trafficking in a recent article in Cell.
Axon terminals containing norepinephrine synapse in the hippocampus and amygdala, which are important in emotional memory. In the hippocampus, norepinephrine reduces the threshold for long-term potentiation (LTP), which is thought to be a substrate of memory. Norepinephrine acts at 
-adrenergic receptors, where it activates cAMP-dependent protein kinase (PKA) and calcium/calmodulin-dependent protein kinase II (CaMKII). These kinases phosphorylate serines 845 and 831, respectively, in the AMPA glutamate receptor type 1 (GluR1). The authors proposed that norepinephrine regulates learning by phosphorylating AMPA receptors.
Hu, H. et al. Emotion enhances learning via norepinephrine regulation of AMPA-receptor trafficking. Cell 131, 160–173 (2007). | Article | PubMed |
