Amygdala Plasticity and Pain

Figure 1

Pain neurocircuitry. Peripheral nociceptive afferent fibers (red lines) form synapses in the dorsal horn of the spinal cord. Axons of spinal dorsal horn neurons decussate in the anterior white commissure and travel in the ventrolateral funiculus (spinothalamic tract; black line) or the dorsolateral funiculus (spino-parabrachio-amygdaloid tract; gray line) to different targets in the brain. Sensory discriminative aspects of pain involve projections from the thalamus to somatosensory cortical areas. Cognitive aspects of pain involve integration within limbic and (prefrontal) cortical regions. Emotional-affective aspects of pain involve integrative processing in the limbic brain regions centered on the amygdala which is a key node. Circuitry is based on [6, 7, 15, 50–58]. Abbreviations: ACC, anterior cingulate cortex; DH, dorsal horn; DRG, dorsal root ganglion; HT, hypothalamus; NAc, nucleus accumbens; PAG, periaqueductal gray; PB, parabrachial nucleus; PFC, prefrontal cortex; S1/2, primary/secondary somatosensory cortex.