Rosen Merri J, Mooney Richard
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
Neuron. 2003 Jul 3;39(1):177-94. doi: 10.1016/s0896-6273(03)00357-x.
Speech and birdsong require auditory feedback for their development and maintenance, necessitating precise auditory encoding of vocal sounds. In songbirds, the telencephalic song premotor nucleus HVC contains neurons that respond highly selectively to the bird's own song (BOS), a property distinguishing HVC from its auditory afferents. We examined the contribution of inhibitory and excitatory synaptic inputs to BOS-evoked firing in those HVC neurons innervating a pathway essential for audition-dependent vocal plasticity. Using in vivo intracellular techniques, we found that G protein-coupled, potassium-mediated inhibition, tuned to the BOS, interacts with BOS-tuned excitation through several mechanisms to shape neuronal firing patterns. Furthermore, in the absence of this inhibition, the response bias to the BOS increases, reminiscent of cancellation mechanisms in other sensorimotor systems.
言语和鸟鸣的发展与维持需要听觉反馈，这就需要对声音进行精确的听觉编码。在鸣禽中，端脑鸣唱前运动核HVC包含对鸟类自身鸣唱（BOS）具有高度选择性反应的神经元，这一特性将HVC与其听觉传入神经区分开来。我们研究了抑制性和兴奋性突触输入对那些支配对听觉依赖的发声可塑性至关重要的通路的HVC神经元中BOS诱发放电的作用。使用体内细胞内技术，我们发现，经BOS调谐的G蛋白偶联钾介导的抑制作用，通过多种机制与BOS调谐的兴奋相互作用，以塑造神经元放电模式。此外，在没有这种抑制作用的情况下，对BOS的反应偏差会增加，这让人联想到其他感觉运动系统中的抵消机制。
