Studies in owls show that, as in V, the Wulst is retinotopically organized and neurons are tuned to spatial frequency and orientation.Furthermore, the majority of cells within the Wulst have receptive fields situated inside the area of binocular overlap.Most cells (about ) are binocular, and sensitive to retinal disparity (Pettigrew and Konishi, Pettigrew, , ; Porciatti et al Wagner and Frost, Nieder and Wagner, ,).Binocular neurons are present in the Wulst of other species, but they will not be as quite a few as they are in owls (Pettigrew, Wilson, Denton, Michael et alFrontiers in Neuroscience www.frontiersin.orgAugust Volume ArticleWylie et al.Evolution of sensory systems in birds).With each other, this suggests that among the primary functions in the visual Wulst is always to mediate binocular vision andor stereopsis.In support of this hypothesis, Iwaniuk and Wylie showed that an enlarged visual Wulst appears to possess evolved in concert with binocular vision in other nocturnal birds at the same time.Each the OwletNightjars (genus Aegotheles) and frogmouths (genus Podargus) are thought to possess stereopsis (Pettigrew,) and have substantial places of binocular overlap rivaling that with the owls (Pettigrew and Konishi, Wallman and Pettigrew, Martin et al a).The Wulst is also very massive in these birds, displaying a related degree of hypertrophy as seen in owls (Figures A,B,D) (Iwaniuk and Wylie, Iwaniuk et al), like a prominent pattern of lamination.The closely related nightjars and potoos (genus Nyctibius) don’t share Escin References thisWulst hypertrophy and have a a lot narrower binocular visual field (Martin et al a,b).The connection involving the size from the Wulst and degree of binocular vision appears to hold beyond these birds using a big degree PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/2153027 of binocular overlap.Making use of a information set including unique species, Iwaniuk et al. examined the partnership between the size in the Wulst and binocular vision making use of orbit orientation as a proxy for binocular overlap (Figure E).The relative size of your Wulst was substantially correlated with orbit orientation (Figure E), but relative TeO size was not.While these many lines of proof indicate that the Wulst is enlarged in species to support binocular vision and worldwide stereopsis, there are actually some clear exceptions.The oilbird (Steatornis caripensis) includes a big binocular overlap (Pettigrew and Konishi,FIGURE Hypertrophy from the nucleus lentiformis mesencephalic (LM) in hummingbirds.(A,B) Photomicrographs displaying the location and borders of LM in coronal sections to get a hummingbird (Forktailed woodnymph, Thalurania furcate) as well as a songbird (Eastern yellow robin, Eopsaltria australis).Even though the brain on the songbird is substantially larger than that on the hummingbird, they share a comparable LM volume.(C) Shows a scatter plot in the relative size of LM as a function of brain minus LM volume (log transformed).The hummingbirds are indicated by the graycircles and also other birds by the white circles.The strong line indicates the least squares linear regression line for all species.(D) Bar graph in the relative size of LM expressed as a percentage of total brain volume.The solid line indicates the mean for all nonhummingbirds as well as the error bars indicate the normal deviations.TeO, optic tectum; LPC, nucleus laminaris precommissuralis; nRt, nucleus rotundus; Glv, lateral geniculate nucleus, ventral leaflet; SOp, stratum opticum.Scale bars .mm (adapted from Iwaniuk and Wylie,).Frontiers in Neuroscience www.frontiersin.orgAugust Volume ArticleWylie et.
