Schroeder C E, Javitt D C, Steinschneider M, Mehta A D, Givre S J, Vaughan H G, Arezzo J C
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Exp Brain Res. 1997 Apr;114(2):271-8. doi: 10.1007/pl00005635.
In area 17 of the awake macaque, disinhibition by blockade of GABA(A) receptors results in a marked elevation in neuronal excitability, with a particular focus in the supragranular laminae. We examined the possibility that the excitatory supragranular response is N-methyl-D-aspartate (NMDA)-mediated. Laminar activity profiles consisting of flash-evoked field potential, current source density (CSD) and multiunit activity (MUA) measures were obtained during striate cortex penetrations using multicontact electrodes that incorporated single or double microinjection cannulae. Profiles were recorded before and at successive time points after bicuculline induction of disinhibition. Both the noncompetitive NMDA antagonist MK-801 and the competitive antagonist APV reversed bicuculline effects, producing a normal laminar activity profile. NMDA-mediated enhancement of excitatory responses in the supragranular laminae of neocortex is believed to play a role in normal signal processing, as well as in epileptic manifestations.
在清醒猕猴的17区，通过阻断GABA(A)受体实现去抑制会导致神经元兴奋性显著升高，尤其集中在颗粒上层。我们研究了兴奋性颗粒上层反应由N-甲基-D-天冬氨酸（NMDA）介导的可能性。在纹状皮层穿刺过程中，使用包含单或双微注射套管的多触点电极获得了由闪光诱发场电位、电流源密度（CSD）和多单位活动（MUA）测量组成的分层活动图谱。在荷包牡丹碱诱导去抑制之前和之后的连续时间点记录图谱。非竞争性NMDA拮抗剂MK-801和竞争性拮抗剂APV均能逆转荷包牡丹碱的作用，产生正常的分层活动图谱。据信，NMDA介导的新皮层颗粒上层兴奋性反应增强在正常信号处理以及癫痫表现中均起作用。
