Vicario D S, Yohay K H
Rockefeller University, New York, New York 10021.
J Neurobiol. 1993 Apr;24(4):488-505. doi: 10.1002/neu.480240407.
Neurons in nuclei on the motor pathway for vocalizations in songbirds are known to respond to sound stimuli. The auditory responses in one such nucleus, robustus archistriatalis (RA), were characterized by making multi-unit recordings in awake and anesthetized adult male zebra finches and in birds that had received lesions of the input to RA from the lateral part of the magnocellular nucleus of the anterior neostriatum (LMAN) or the Higher Vocal Center (HVC). In awake birds, RA neurons have a high level of spontaneous activity and vigorous auditory responses to song stimuli. Significantly greater responses are seen to the bird's own song (BOS) than to BOS played in reverse (REV) or to the songs of conspecifics (CON). Under ketamine-xylazine anesthesia, spontaneous activity is reduced, response latency increases and responses to BOS, REV and CON are indistinguishable. Responses obtained under urethane anesthesia are similar to those seen in awake birds. Thus, the pattern and selectivity of auditory responses in RA depend on the animal's state. Auditory responses in RA are qualitatively unchanged following lesion of the input to RA from LMAN, indicating that this pathway is not required for the sensory processing that underlies the preference for BOS on the vocal production pathway. Our results show that an input other than that from LMAN must be primarily responsible for auditory responses in RA. The direct projection from HVC is the most likely pathway by which song selective auditory information arrives in RA, since lesioning HVC abolished auditory responses in RA.
已知鸣禽发声运动通路中核团的神经元对声音刺激有反应。在一个这样的核团，即古纹状体粗核（RA）中，通过在清醒和麻醉的成年雄性斑胸草雀以及接受了来自前新纹状体大细胞外侧核（LMAN）或高级发声中枢（HVC）至RA的输入损伤的鸟类中进行多单位记录，对听觉反应进行了特征描述。在清醒的鸟类中，RA神经元具有高水平的自发活动，并且对歌曲刺激有强烈的听觉反应。与反向播放的自身歌声（REV）或同种个体的歌声（CON）相比，对鸟类自身的歌声（BOS）的反应明显更大。在氯胺酮 - 赛拉嗪麻醉下，自发活动减少，反应潜伏期增加，对BOS、REV和CON的反应没有区别。在乌拉坦麻醉下获得的反应与在清醒鸟类中观察到的相似。因此，RA中听觉反应的模式和选择性取决于动物的状态。在LMAN至RA的输入损伤后，RA中的听觉反应在质量上没有变化，这表明在发声产生通路中对BOS偏好的感觉处理所依据的感觉处理不需要该通路。我们的结果表明，除了来自LMAN的输入之外，其他输入必定是RA中听觉反应的主要原因。从HVC的直接投射是歌曲选择性听觉信息到达RA的最可能途径，因为损伤HVC消除了RA中的听觉反应。
