Martin-Elkins C L, Horel J A
Department of Anatomy and Cell Biology, SUNY Health Science Center, Syracuse 13210.
J Comp Neurol. 1992 Jul 8;321(2):177-92. doi: 10.1002/cne.903210202.
The inferior temporal gyrus in the monkey appears to be unique among the many extrastriate visual cortices in its importance for normal performance of delayed match-to-sample, a visual memory task. However, the anatomical pathway providing visual information to this portion of the temporal lobe remains unclear. In this study, wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was injected into the anterior inferior temporal gyrus and heavy projections were found to arise in cytoarchitectural area TF of the parahippocampal gyrus, as well as moderate projections in more posterior portions of inferior temporal gyrus and perirhinal and entorhinal cortices. Subsequently, WGA-HRP was injected into area TF, resulting in retrogradely labeled cells primarily located in the portions of area TF adjacent to the injection and also in the occipitotemporal sulcus including the ventral portion of the prestriate visual area V4. Moderate projections were found to originate from the dorsal region of area V4 in the lunate sulcus, portions of the caudal parietal lobe, the posterior bank of caudal superior temporal sulcus, and area OPT located at the tip of the superior temporal sulcus. The middle temporal gyrus, foveal prestriate cortex, and area TEO, a transitional area between temporal and occipital visual areas, were all free from retrogradely labeled cells. These latter areas are included in the well-established anatomical system that is known to carry visual information from striate cortex through prestriate to eventually reach dorsal portions of inferotemporal cortex which is coincident with the temporal lobe visual area TE. It is suggested here that there is an additional ventral pathway into area TE as well, which includes projections through portions of the prestriate cortex, occipitotemporal sulcus, and parahippocampal gyrus, ultimately reaching the anterior inferior temporal gyrus, an area that may be specialized to hold visual information over brief periods of time.
猴子的颞下回在众多纹外视觉皮层中,对于延迟匹配样本这一视觉记忆任务的正常执行似乎具有独特的重要性。然而,向颞叶这一部分提供视觉信息的解剖学通路仍不清楚。在本研究中,将与辣根过氧化物酶结合的小麦胚芽凝集素(WGA-HRP)注入颞下回前部,发现海马旁回的细胞构筑区TF有大量投射,颞下回后部、梨状周围皮质和内嗅皮质也有中等强度的投射。随后,将WGA-HRP注入TF区,导致逆行标记的细胞主要位于与注射部位相邻的TF区部分,以及枕颞沟,包括纹前视觉区V4的腹侧部分。发现中等强度的投射起源于月状沟内V4区的背侧区域、尾侧顶叶的部分、尾侧颞上沟的后壁,以及位于颞上沟顶端的OPT区。颞中回、中央凹纹前皮质和TEO区(颞叶和枕叶视觉区之间的过渡区)均未发现逆行标记的细胞。后几个区域包含在一个成熟的解剖系统中,已知该系统从纹状皮质通过纹前皮质携带视觉信息,最终到达颞下皮质的背侧部分,这与颞叶视觉区TE一致。本文认为,还存在一条通向TE区的额外腹侧通路,该通路包括通过纹前皮质部分、枕颞沟和海马旁回的投射,最终到达颞下回前部,该区域可能专门用于在短时间内保存视觉信息。