Cotillon N, Edeline J M
Laboratoire de Neurobiologie de l'Apprentissage, de la Mémoire et de la Communication, CNRS UMR 8620, Université Paris-Sud, Bât 446, 91405 Orsay, France.
Eur J Neurosci. 2000 Oct;12(10):3637-50. doi: 10.1046/j.1460-9568.2000.00254.x.
This study investigates the origins of tone-evoked oscillations (5-13 Hz) in the thalamo-cortical auditory system of anaesthetized rats. In three separate experiments, the auditory sector of the reticular nucleus (RE), the auditory cortex and the auditory thalamus were inactivated by local applications of muscimol (1 mg/mL). To assess the efficacy of this procedure, recordings were performed in the inactivated structure in each experiment; and to determine the extent of the drug diffusion autoradiographic experiments were carried out. The evolution of the strength of the oscillations was followed using power spectra during the whole recording session. In the first experiment, muscimol injection in the auditory RE totally suppressed the tone-evoked oscillations in the auditory thalamus and cortex. In the second experiment, inactivation of the auditory cortex did not interfere with the presence of tone-evoked oscillations in the auditory RE. In the third experiment, inactivation of the auditory thalamus impaired the oscillations produced by cortical stimulation in the auditory RE. From these results, it appears that both the auditory thalamus and the auditory sector of the RE, but not the auditory cortex, are involved in the generation of stimulus-evoked oscillations in the thalamo-cortical auditory system.
本研究调查了麻醉大鼠丘脑 - 皮质听觉系统中音调诱发振荡（5 - 13赫兹）的起源。在三个独立实验中，通过局部应用蝇蕈醇（1毫克/毫升）使网状核（RE）的听觉部分、听觉皮层和听觉丘脑失活。为评估该操作的效果，在每个实验中对失活结构进行记录；并通过放射自显影实验确定药物扩散范围。在整个记录过程中，使用功率谱跟踪振荡强度的变化。在第一个实验中，向听觉RE注射蝇蕈醇完全抑制了听觉丘脑和皮层中的音调诱发振荡。在第二个实验中，听觉皮层失活并未干扰听觉RE中音调诱发振荡的存在。在第三个实验中，听觉丘脑失活削弱了听觉RE中由皮层刺激产生的振荡。从这些结果来看，似乎丘脑和RE的听觉部分而非听觉皮层参与了丘脑 - 皮质听觉系统中刺激诱发振荡的产生。
