Martin Claire, Gervais Rémi, Messaoudi Belkacem, Ravel Nadine
Institut des Sciences Cognitives, UMR 5015 CNRS-Université Lyon I, IFR19, Institut Fédératif des Neurosciences de Lyon, Bron, 69675 France.
Eur J Neurosci. 2006 Apr;23(7):1801-10. doi: 10.1111/j.1460-9568.2006.04711.x.
In trained behaving rats, the expression of a prominent beta oscillatory activity in the olfactory system was previously identified as a correlate of odour recognition. The aim of the present study was to assess the putative role of a functional coupling between the olfactory bulb (OB) and higher structures in this activity. We performed a unilateral inactivation of the medial part of the olfactory peduncle by lidocaine infusion. Inactivation deprived the OB from most of its centrifugal afferences, including feedback connections from the piriform cortex (PC) while sparing the ascending fibres from the OB to higher cortical structures. This treatment reduced the amplitude of odour-induced oscillatory beta responses both in OB and PC. In parallel, gamma activity classically observed in these two structures during spontaneous activity displayed a strong enhancement. Results suggest that odour-induced oscillatory response could be the emergent feature of an olfactory functional network set up through learning.
在经过训练的行为大鼠中，嗅觉系统中一种显著的β振荡活动的表达先前被确定为气味识别的一个相关因素。本研究的目的是评估嗅球（OB）与更高结构之间功能耦合在这种活动中的假定作用。我们通过注入利多卡因对嗅柄内侧部分进行单侧失活。失活使嗅球失去了大部分离心传入纤维，包括来自梨状皮质（PC）的反馈连接，同时保留了从嗅球到更高皮质结构的上行纤维。这种处理降低了嗅球和梨状皮质中气味诱导的振荡β反应的幅度。同时，在自发活动期间在这两个结构中经典观察到的γ活动显示出强烈增强。结果表明，气味诱导的振荡反应可能是通过学习建立的嗅觉功能网络的涌现特征。
