In vivo imaging analyses to explore the integration of multimodal aversive sensory information in the central amygdala

The negative emotions elicited by diverse aversive sensory stimuli induce avoidance behaviors and adaptive autonomic/hormonal responses, which are crucial for biological defense and homeostasis. The central amygdala (CeA), which receives a range of sensory information, plays important roles in stress and emotional responses. However, it remains unclear whether diverse sensory information from different sensory systems, such as the pain, olfactory, and gustatory systems, is received by the same group of CeA neurons and then integrated to generate negative emotions, or whether different neural pathways are used to generate negative emotions without converging on a specific group of CeA neurons. To clarify this issue, we conducted in vivo Ca²⁺ imaging to measure CeA neuron activity in response to aversive pain, olfactory, and gustatory stimuli. The results revealed that 144 of the 263 CeA neurons identified were activated by one or more types of aversive sensory stimuli: 70.8% of the activated neurons responded to only one stimulus, 24.3% to any two stimuli, and only 4.9% to all three, suggesting that the specificity of CeA neurons to aversive stimuli is relatively high, while some neurons respond multiple aversive stimuli. Aversive sensory information from different sensory pathways may be partially integrated in the CeA.