Comparison between offset and onset responses of primary auditory cortex ON-OFF neurons in awake cats
Comparison between offset and onset responses of primary auditory cortex ON-OFF neurons in awake cats
复制标题
DOI：
10.1152/jn.00184.2007
复制
发表时间：
2007-05-01
影响因子：
2.5
通讯作者：
Sato, Yu
中科院分区：
文献类型：
--
作者：
Qin, Ling;Chimoto, Sohei;Sato, Yu
初级听觉皮层（A1）神经元被认为不携带太多关于音调偏移的信息，因为巴比妥酸盐麻醉动物中的A1神经元通常被描述为只有起始反应。我们调查的音调偏移反应比较，在清醒的猫的尾侧部分的A1的起始反应。对起始和偏移都有反应的细胞是常见的（占记录细胞的59.2%）。偏移反应通常与阶段性发作反应或持续反应的阶段性成分同时发生。这些ON-OFF细胞具有不同的偏移频率和起始频率感受野（FRF）组合：偏移频率FRF类似于起始频率FRF，或比起始频率FRF更窄、更宽、更低或更高。FRF模式的分布是弥漫性的，不同的FRF模式组之间没有边界。在多个刺激强度下，每个细胞的起始与偏移FRF模式保持不变。与平均起始反应相比，平均偏移反应显示出相似的峰值潜伏期（19.5 vs. 21.5 ms）、较长的半衰减时间（74.5 vs. 48.5 ms）和较低的峰值振幅（20.4 vs. 35.9 spikes/s）。虽然偏移响应时，促进了抑制穗活动之前，他们仍然引起没有前面的穗抑制。结果表明，在尾侧A1区，出现成对起始和偏移反应的神经元占优势。它们的频率过滤特性通常不是静态的，而是动态的，在声音开始和结束之间变化。偏移响应与用于有效编码声音偏移的起始响应类似地精确和突出。它们可能是作为对声音抵消的主动锋电位反应而不是简单的反弹促进而引起的。
Primary auditory cortex (A1) neurons are believed not to carry much information about tonal offsets because A1 neurons in barbiturate- anesthetized animals are usually described as having only onset responses. We investigated tonal offset responses in comparison with onset responses in the caudal part of A1 of awake cats. Cells responding to both onsets and offsets were commonly found (59.2% of recorded cells). Offset responses usually co-occurred with phasic onset responses or phasic components of sustained responses. These ON-OFF cells had diverse combinations of offset- and onset-frequency-receptive field (FRF): offset-FRF was similar to onset-FRF, or narrower, wider, lower, or higher than onset-FRF. The distribution of FRF patterns was diffuse with no boundaries between the different FRF-pattern groups. The onset- versus offset-FRF pattern of each cell remained unchanged across multiple stimulus intensities. Mean offset response showed similar peak latency (19.5 vs. 21.5ms), longer half-decay time (74.5 vs. 48.5 ms), and lower peak amplitude (20.4 vs. 35.9 spikes/s) compared with the mean onset response. Although offset responses were facilitated when preceded by the suppression of spike activity, they were still elicited without preceding spike suppression. It is concluded that neurons showing paired onset and offset responses are predominant in the caudal A1. Their frequency-filtering property is usually not static but dynamic, changing between sound onsets and offsets. Offset responses are similarly precise and salient as onset responses for effectively encoding sound offsets. They may be elicited as active spike responses to sound offset rather than simple rebound facilitation.