Rapid detection and response to visual threats are critical for survival in animals. The amygdala (AMY) is hypothesized to be involved in this process, but how it interacts with the visual system to do this remains unclear. By recording flash-evoked potentials simultaneously from the superior colliculus (SC), lateral posterior nucleus of the thalamus, AMY, lateral geniculate nucleus (LGN) and visual cortex, which belong to the cortical and subcortical pathways for visual fear processing, we investigated the temporal relationship between these regions in visual processing in rats. A quick flash-evoked potential (FEP) component was identified in the AMY. This emerged as early as in the LGN and was approximately 25 ms prior to the earliest component recorded in the SC, which was assumed to be an important area in visual fear. This quick P1 component in the AMY was not affected by restraint stress or corticosterone injection, but was diminished by RU38486, a glucocorticoid receptor blocker. By injecting a monosynaptic retrograde AAV tracer into the AMY, we found that it received a direct projection from the retina. These results confirm the existence of a direct connection from the retina to the AMY, that the latency in the AMY to flashes is equivalent to that in the sensory thalamus, and that the response is modulated by glucocorticoids.

快速检测和响应视觉威胁对于动物的生存至关重要。假设杏仁核 (AMY) 参与了这一过程，但它如何与视觉系统相互作用以做到这一点仍不清楚。通过同时记录上丘（SC）、丘脑外侧后核、AMY、外侧膝状体核（LGN）和视觉皮层（属于视觉恐惧处理的皮质和皮质下通路）的闪光诱发电位，我们研究了大鼠视觉处理中这些区域之间的时间关系。在 AMY 中发现了一个快速闪光诱发电位 (FEP) 组件。这早在 LGN 中就出现了，大约比 SC 中记录的最早成分早了 25 毫秒，这被认为是视觉恐惧的一个重要区域。AMY 中的这种快速 P1 成分不受约束压力或皮质酮注射的影响，但被糖皮质激素受体阻滞剂 RU38486 减少。通过将单突触逆行 AAV 示踪剂注入 AMY，我们发现它收到了来自视网膜的直接投射。这些结果证实存在从视网膜到 AMY 的直接连接，AMY 对闪光的潜伏期与感觉丘脑中的潜伏期相同，并且反应受糖皮质激素的调节。