Binns K E, Salt T E
Department of Visual Science, Institute of Ophthalmology, London, UK.
Eur J Neurosci. 1994 Jan 1;6(1):161-9. doi: 10.1111/j.1460-9568.1994.tb00257.x.
The contribution of NMDA and non-NMDA receptors to visual synaptic transmission in the superficial layers of the superior colliculus of the cat has been studied using extracellular recording and iontophoretic techniques. Neuronal responses to natural visual stimulation and the ejection of NMDA and AMPA were observed in the absence and presence of the antagonists CNQX, CPP and AP5. CNQX routinely reduced the responses to visual stimulation at ejection currents which selectively blocked the responses to AMPA but not those to NMDA. Agonist selective ejection currents of CPP and AP5 also reduced visual responses of most SC neurons, but there was a substantial majority whose visual responses were resistant to these antagonists. Neurons with CPP/AP5 resistant visual responses were more commonly found 750-1000 microns from the dorsal surface of the SC. The data indicate that, while non-NMDA receptors are heavily involved in visual synaptic transmission in the superficial SC, the involvement of NMDA receptors varies with recording depth.
利用细胞外记录和离子电泳技术，研究了NMDA和非NMDA受体在猫上丘表层视觉突触传递中的作用。在不存在和存在拮抗剂CNQX、CPP和AP5的情况下，观察了神经元对自然视觉刺激以及NMDA和AMPA注入的反应。CNQX通常会在注入电流时降低对视觉刺激的反应，该电流选择性地阻断了对AMPA的反应，但未阻断对NMDA的反应。CPP和AP5的激动剂选择性注入电流也降低了大多数上丘神经元的视觉反应，但有相当一部分神经元的视觉反应对这些拮抗剂具有抗性。在距离上丘背表面750 - 1000微米处更常见到对CPP/AP5具有抗性的视觉反应的神经元。数据表明，虽然非NMDA受体在表层上丘的视觉突触传递中起重要作用，但NMDA受体的作用随记录深度而变化。
