Brett B, Barth D S
Department of Psychology, University of Colorado, Boulder 80309-0345, USA.
J Neurophysiol. 1997 Aug;78(2):573-81. doi: 10.1152/jn.1997.78.2.573.
The purpose of this study was to use depth electrical stimulation and retrograde horseradish peroxidase (HRP) labeling to determine what role certain subcortical nuclei play in the neurogenesis of high-frequency gamma (approximately 40 Hz) oscillations in rat auditory cortex. Evoked and spontaneous electrocortical oscillations were recorded with the use of a high-spatial-resolution multichannel epipial electrode array while electrical stimulation was delivered to the posterior intralaminar (PIL) region of the ventral acoustic thalamus and to the centrolateral nucleus (CL) and the nucleus basalis (NB), which have been previously implicated in the production of cortical gamma oscillations. PIL stimulation consistently evoked gamma oscillations confined to a location between primary and secondary auditory cortex, corresponding to the region where spontaneous gamma oscillations were also recorded. Stimulation of the CL and NB did not evoke gamma oscillations in auditory cortex. HRP placed in the cortical focus of evoked gamma oscillations labeled cell bodies in the PIL, and in more lateral regions of the ventral acoustic thalamus, which on subsequent stimulation also evoked gamma oscillations in auditory cortex. No cells were labeled in either the CL or NB. These results indicate that the PIL and the lateral regions of ventral acoustic thalamus provide anatomically distinct input to auditory cortex and may play an exclusive and modality-specific role in modulating gamma oscillations in the auditory system.
本研究的目的是利用深度电刺激和逆行辣根过氧化物酶（HRP）标记，以确定某些皮层下核团在大鼠听觉皮层高频γ（约40Hz）振荡的神经发生中所起的作用。使用高空间分辨率的多通道软脑膜电极阵列记录诱发和自发的皮层电振荡，同时将电刺激施加到腹侧听觉丘脑的后内侧核（PIL）区域以及中央外侧核（CL）和基底核（NB），先前已表明这些区域与皮层γ振荡的产生有关。PIL刺激始终诱发局限于初级和次级听觉皮层之间位置的γ振荡，该位置与也记录到自发γ振荡的区域相对应。刺激CL和NB未在听觉皮层诱发γ振荡。置于诱发γ振荡皮层焦点处的HRP标记了PIL以及腹侧听觉丘脑更外侧区域的细胞体，这些区域在随后的刺激中也在听觉皮层诱发了γ振荡。CL或NB中均未标记到细胞。这些结果表明，PIL和腹侧听觉丘脑的外侧区域为听觉皮层提供了解剖学上不同的输入，并且可能在调节听觉系统中的γ振荡方面发挥独特的、模态特异性的作用。
