Sullivan R M, Wilson D A, Lemon C, Gerhardt G A
Department of Psychology, University of Oklahoma, Norman 73019.
Brain Res. 1994 Apr 18;643(1-2):306-9. doi: 10.1016/0006-8993(94)90038-8.
On postnatal day 4 (PN4) Wistar rat pups were anesthetized and received bilateral infusions of 6-OHDA into the locus coeruleus or received vehicle infusions. On PN6 pups were trained in a classical conditioning paradigm with intra-oral milk infusions as the UCS and citral odor as the CS. Pups were trained in either 'paired', 'odor-only', 'milk-only' or 'backward' (milk then odor) conditions. On PN7 acquisition of a learned odor preference to the CS was tested in a two-odor choice test. HPLC analysis showed that locus coeruleus lesions significantly reduced olfactory bulb NE content but had no effect on olfactory bulb DA or 5-HT levels compared to controls. Pups receiving locus coeruleus lesions did not differ in behavioral response patterns during training compared to their littermate, vehicle controls. However, locus coeruleus lesions impaired acquisition of conditioned odor preferences. These results suggest that NE output from the locus coeruleus is critical for early olfactory learning.
在出生后第4天（PN4），将Wistar大鼠幼崽麻醉，并向其蓝斑双侧注射6-羟基多巴胺（6-OHDA）或注射溶剂。在PN6时，幼崽接受经典条件反射范式训练，以口腔内注入牛奶作为无条件刺激（UCS），柠檬醛气味作为条件刺激（CS）。幼崽分别在“配对”“仅气味”“仅牛奶”或“反向”（先牛奶后气味）条件下接受训练。在PN7时，通过双气味选择测试来检测对CS习得的气味偏好的获得情况。高效液相色谱分析表明，与对照组相比，蓝斑损伤显著降低了嗅球中去甲肾上腺素（NE）的含量，但对嗅球中多巴胺（DA）或5-羟色胺（5-HT）水平没有影响。与同窝接受溶剂注射的对照幼崽相比，接受蓝斑损伤的幼崽在训练期间的行为反应模式没有差异。然而，蓝斑损伤会损害条件性气味偏好的获得。这些结果表明，蓝斑的NE输出对早期嗅觉学习至关重要。
