Synaptic Tagging in the ACC: Basic Mechanisms and Functional Implications

Synaptic tagging and capture (STC) is believed to play important roles in hippocampus-related associative memory. Recent studies in the anterior cingulate cortex (ACC), a key cortical region for pain and emotion, indicate that excitatory synapses are highly plastic and can undergo different forms of plasticity, including long-term potentiation (LTP), long-term depression (LTD), and metaplasticity. STC has been reported in the ACC of adult mice. Considering ACC neurons receive divergent projections from cortical and subcortical areas, STC may provide a key synaptic mechanism for information integration, memory formation, as well as pathological changes in disease conditions. In this chapter, we will first review current knowledge of ACC anatomy and different forms of LTP and LTD in this area. Then, ACC-STC and its functional relevant roles in pain and aging will be reviewed. Due to limited information on synaptic mechanisms, we will explore possible plasticity-related proteins (PRP) as well as diffusible messengers in ACC-STC. Finally, the physiological and pathological significance of ACC-STC will be discussed at the end. Network interaction between ACC and other brain regions, and its synaptic regulation and STC are future directions for basic research.