The present study examines the gross anatomical features of anomalous lunate sulcus detected incidentally in a cadaveric brain and discusses its clinical importance. The absence of lunate sulcus was carefully studied in a dissected brain specimen. The absence of lunate sulcus was observed unilaterally on the right side of a cadaveric brain specimen. The lunate sulcus was clearly appreciated on the left side whilst on the right side it was absent. The absence of lunate sulcus is a rare finding, which may be detected incidentally. The anatomical knowledge of the lunate sulcus may be important for neurosurgeons operating on the occipital lobe and the radiologists interpreting CT scan.. 
The following primary sulci were then visible until ED 120: the superior temporal sulcus on ED 90; the intraparietal sulcus, lunate sulcus, inferior occipital sulcus, and arcuate sulcus on ED 100; and the principle sulcus on ED 110; the occipitotemporal sulcus, anterior middle temporal sulcus, and superior postcentral dimple on ED 120.
The position of the lunate sulcus in fossil endocasts (when it can be determined) may serve as a potential marker of cognitive development in extinct hominid species. While the lunate sulcus is reliably present in the brains of great apes and forms the anterolateral boundary of the primary visual cortex, in humans its presentation is much more variable, and even if present, it does not correspond to a functional region. Grafton Elliot Smith, who named the lunate sulcus, claimed that it was homologous in humans and the great apes. Using high-resolution MRI, we assessed the presence/absence and course of the lunate sulcus in 110 adult subjects. We found that in the vast majority of cases, lunate sulci identified on the surface of the occipital lobe are actually composed of smaller sulcal segments that converge into an apparently continuous composite lunate sulcus.
The V2 projection to V3 A was labeled by pressure microinjecting biotinylated dextran amine (BDA) and Phaseolus vulgaris lectin (PHA-L) into V2 just posterior to the lunate sulcus.
LB1 has derived frontal and temporal lobes and a lunate sulcus in a derived position, which are consistent with capabilities for higher cognitive processing..
In nonhuman primates, this region is larger in volume (demarcated anteriorly by the lunate sulcus), and extends further rostrally than it does in modern humans.
The spatial extent of the beta preparatory activity was monitored using an array of 15 epidural electrodes, positioned in 2 rows stretching from the arcuate sulcus to the lunate sulcus.
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.
Large terminal fields are asymmetrical, with their long axis oriented in an anterior-posterior fashion toward the depth of the lunate sulcus.
For this reason, all our recordings were made in or near the fundus of the lunate sulcus.
I have identified and illustrated a spherical "dimple" or "depression" on the Taung endocast as indicating the most likely position of the medial end of the lunate sulcus but have not drawn an actual lunate sulcus on Taung because one is not visible. 77:27-33, 1988) drew a lunate sulcus on his copy of the Taung endocast, incorrectly attributed this sulcus to me, and used it to obtain a ratio of 0.254 to describe "Falk's" position of the lunate sulcus. 67:313-315, 1985a) was not considered, although the focus of Holloway's paper was my assessment of the position of the lunate sulcus. Assessment of Holloway's chimpanzee data supports my claim that the dimple on the Taung endocast is within the chimpanzee range for the medial end of the lunate sulcus..
The analyses were made in a portion of area 17 on the lateral surface of the hemisphere just caudal to the lunate sulcus.
Using an increased sample of chimpanzee brains and brain casts, 32 hemispheres were measured to determine the variability of OP-FP (occipital-pole) and OP-LS (occipital pole-lunate sulcus) arc dimensions and their ratios. The Taung endocast was remeasured to test Falk's assertions that the lunate sulcus is in a pongid position. The average ratio for the chimpanzee brains was 0.218, a value more than 2+ S.D.'s posterior to Falk's placement of the lunate sulcus on the Taung specimen.
In the adult, area V1 and V2 project contralaterally to two heterotopic sites located in the fundus of the lunate sulcus and the superior temporal sulcus.
The V1/V2 border was found to have reciprocal connections with the contralateral visual area V1, as well as with three other cortical sites situated in the posterior bank of the lunate sulcus, the anterior bank of the lunate sulcus, and the posterior bank of the superior temporal sulcus. In the posterior bank of the lunate sulcus, labeled terminals were scattered throughout all cortical layers except layers 1 and 4. In the anterior bank of the lunate sulcus and in the superior temporal sulcus, anterograde labeled terminals were largely focused in layer 4. In the posterior bank of the lunate sulcus, columns of callosal connections were superimposed on regions of high cytochrome activity.
The vertical meridian runs caudally within the lunate sulcus, the horizontal meridian crosses the prelunate gyrus and continues into the superior temporal sulcus.
In the cortex, the labeled neurons extended from the fundus of the lunate sulcus to the fundus of the superior temporal sulcus.
Holloway (1984) used a method of direct tape-arc measurements on chimpanzee brain casts to reject the hypothesis that the lunate sulcus is located in an anterior position in the Taung endocast. However, Holloway neglected to measure the occipital pole-lunate sulcus (OP-LS) arc directly on the Taung endocast as he did on chimpanzee brain casts (a crucial part of his methodology); instead, he determined the relative position of Taung's lunate sulcus on the basis of a calculation that confounds direct measurements and measurements from photographs. When arc OP-LS is measured directly on Taung according to Holloway's methods, the feature that has been identified as the medial end of the lunate sulcus is shown to be located within the range that Holloway determined for chimpanzees. Thus Holloway's methodology and data support rather than refute the claim that the lunate sulcus is located in a pongid-like position in australopithecines..
Area PM occupies part of the prelunate gyrus and extends into the anterior bank of the lunate sulcus.
Using an independent method of direct tape-arc measurements on six chimpanzee brain casts, it is shown that Falk's (1980, 1983) claims regarding an anterior pongidlike placement of a lunate sulcus on the Taung specimen remain unconfirmed. Falk's (1980) placement of a lunate sulcus falls at least 2.5 standard deviations anterior to a position expected on the basis of a Pan location..
Stereotaxic measurements were taken in situ of the highest points on the cortical surface, the position of the central and lunate sulcus, and of certain landmarks at the base of the cranium in a large number of monkeys.
Indices of rostrality (ir, ir') are developed to assess the extent to which the medial end of the lunate sulcus (L) is rostrally positioned in photographs and figures of lateral views of primate brains and endocasts, and indices are determined for chimpanzees, SK 1585 and the Taung endocast. The ir of the feature that I have identified as the lunate sulcus of Taung is within one standard deviation of the mean ir for Pan and its ir' is within 1.5 standard deviations from the mean ir' for Pan. Both findings are compatible with my earlier statement that the medial end of the lunate sulcus of the Taung endocast is in a pongid-like position. Use of stereoplotting to transfer the position of L from chimpanzee endocasts and brains to australopithecine endocasts is critically assessed: Holloway stereoplotted five chimpanzee brains and then transferred their mean coordinates that describe the lunate sulcus to the Taung endocast. However, the ir of the lunate sulcus that Holloway located on Taung is over two standard deviations lower than the mean ir for the five chimpanzees he stereoplotted to determine its angular coordinates, and Holloway's ir' for Taung is one standard deviation lower than the five chimpanzees' mean ir'.
The directions of the major axes were perpendicular to the lunate sulcus in the sections adjacent to the lunate sulcus, and parallel to the horizontal meridian in sections taken from the region of the representation of the meridian, suggesting that the basal dendritic fields are orientated in parallel with the directions of the ocular dominance bands..
Receptive field properties of cells deep in the posterior bank of lunate sulcus and on the annectant gyrus (V3) were studied in the awake, fixating monkey.
Contrary to earlier descriptions, the lunate sulcus occupies a rostral position similar to that found in pongids.
Transcallosal fibres terminate in a narrow strip of cortex along the boundary between striate and prestriate areas and in a separate, broader, zone occupying much of the anterior bank of the lunate sulcus, the annectant gyrus, and the parietooccipital sulcus.
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