Skorina Laura K, Recktenwald Eric W, Dudkin Elizabeth A, Saidel William M, Gruberg Edward R
Temple University, Department of Biology, 1900 North 12th Street, Philadelphia, PA 19122, USA.
Alvernia University, 400 Saint Bernardine Street, Reading, PA 19607, USA.
Neurosci Lett. 2016 May 16;621:34-38. doi: 10.1016/j.neulet.2016.03.057. Epub 2016 Apr 6.
We used physiological and anatomical methods to elucidate how the visual field is represented in the part of the dorsal anterior thalamus of the leopard frog that receives direct retinal projections. We recorded extracellularly while presenting visual stimuli, and characterized a physiologically defined region that encompasses the retinal projections as well as an extended zone beyond them. We probed the area systematically to determine if the zone is organized in a visuotopic map: we found that it is not. We found that units in this region respond only to stimuli in the contralateral half of the visual field, which is similar to what is seen in the dorsal lateral geniculate nucleus in mammals. When we backfilled retinal ganglion cells from application of HRP to the anterior thalamus, we found labeled cells only in those parts of the retina corresponding to the contralateral hemifield, confirming our physiological observations.
我们运用生理学和解剖学方法，以阐明豹蛙背侧丘脑前部接收视网膜直接投射的区域是如何表征视野的。我们在呈现视觉刺激时进行细胞外记录，并确定了一个生理学定义的区域，该区域包含视网膜投射以及其外的一个扩展区域。我们系统地探测该区域，以确定该区域是否以视拓扑图的形式组织：我们发现并非如此。我们发现该区域的神经元仅对视野对侧半部分的刺激做出反应，这与在哺乳动物背外侧膝状核中观察到的情况类似。当我们通过将辣根过氧化物酶（HRP）应用于丘脑前部来逆向标记视网膜神经节细胞时，我们仅在视网膜中与对侧半视野相对应的那些部分发现了标记细胞，这证实了我们的生理学观察结果。
