Electrophysiological Identification of a Visual Area in Shark Telencephalon

Cohen, David H.; Duff, Thomas A.; Ebbesson, Sven O. E.

doi:10.1126/science.182.4111.492

Cited by 88 publications

(20 citation statements)

References 7 publications

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“…These projections were considered to be homologous to the ascending thalamocortical projections found in 'higher' vertebrates [Ebbesson and Schroeder, 1971;Ebbesson, 1980]. Subsequently, a number of anatomical and physiological studies confirmed the presence of ascending projections to the pallium [Cohen et al, 1973;Platt et al, 1974;Bullock and Corwin, 1979;Luiten, 1981b;Bodznick and Northcutt, 1984;Bleckmann et al, 1987Bleckmann et al, , 1989Smeets and Northcutt, 1987;Fiebig and Bleckmann, 1989;Bodznick, 1991]. The conclusion at that time, which is still believed today, is that the telencephalon of elasmobranchs has large 'non-olfactory' areas that are innervated by ascending diencephalic projections carrying information from other sensory modalities to the telencephalon.…”

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confidence: 81%

“…At that time, only the secondary and tertiary olfactory projections were known, and these do not reach the dorsomedial pallium [Ebbesson and Heimer, 1970;Ebbesson, 1972;Smeets, 1983;Dreyer and Graziadei, 1994]. Then, ascending non-olfactory projections to the dorsomedial pallium were discovered, which led to the valid conclusion that other sensory modalities occupy these non-olfactory areas [Cohen et al, 1973;Platt et al, 1974;Bullock and Corwin, 1979;Luiten, 1981b;Bodznick and Northcutt, 1984;Bleckmann et al, 1987Bleckmann et al, , 1989Smeets and Northcutt, 1987;Fiebig and Bleckmann, 1989;Bodznick, 1991]. The problem was that these studies focused on non-olfactory sensory systems and nobody investigated further olfactory pathways.…”

Section: Discussionmentioning

confidence: 99%

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Organization of Major Telencephalic Pathways in an Elasmobranch, the Thornback Ray Platyrhinoidis triseriata

Hofmann

Northcutt²

2008

Brain Behav Evol

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The forebrain of elasmobranchs is well developed, and in some species the relative brain/body weight is comparable to that in mammals. However, little is known about the organization of major telencephalic pathways. We injected biotinylated dextran amines into the olfactory bulb, lateral pallium, dorsomedial pallium, and the forebrain bundles of the thornback ray, Platyrhinoidis triseriata. Secondary olfactory fibers from the bulb innervate the lateral pallium, the ventral division of the rostral telencephalon and area superficialis basalis. Retrogradely labeled cells were seen exclusively in the lateral periventricular area. The projections of the lateral pallium appeared basically similar to those of the olfactory bulb, but labeling was much denser in the superficial part of area basalis. Some fibers were also seen to innervate the posterior tuberal nucleus. Injections into the dorsomedial pallium revealed a major input from area basalis. Only a few cells were retrogradely labeled in the dorsal thalamus and posterior lateral thalamic nucleus. Major efferents of the dorsomedial pallium appear to reach the contralateral inferior lobe of the hypothalamus and the lateral mesencephalic nucleus. Tracer injections into the forebrain bundles retrogradely labeled many cells in the diencephalon and the mesencephalon and also revealed terminal fields in area superficialis basalis. In addition, a large number of cells were labeled in the dorsomedial pallium. Descending telencephalic fibers innervate heavily the inferior lobes and the lateral mesencephalic nucleus. Our results show that higher order olfactory pathway courses from the lateral pallium through area basalis to the dorsomedial pallium and that ascending non-olfactory input is integrated in area superficialis basalis and the dorsal pallium along with olfactory information, rather than being processed in separate, non-olfactory centers.

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mentioning

confidence: 81%

Section: Discussionmentioning

confidence: 99%

Organization of Major Telencephalic Pathways in an Elasmobranch, the Thornback Ray Platyrhinoidis triseriata

Hofmann

Northcutt²

2008

Brain Behav Evol

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“…Karamian et al (1973) have given evidence that dorsal column stimulation of the spinal cord in the lamprey (Lampetra fluviatilis) causes telencephalic evoked potentials, so somatic sensory information may project to this area. Cohen et al (1973) have also claimed the existence of a visual projection, in the telencephalon of the shark (Ginglymostoma cirratum), in the central telencephalic area. Platt et al (1974) have reported that various types of input in some elasmobranchs, primarily Torpedo and Scyliorhinus, can cause specific evoked potentials in the telencephalon.…”

Section: Specific Sensory Afferencementioning

confidence: 96%

The Fish Telencephalon and Its Relation to Learning

Savage

1980

Comparative Neurology of the Telencephalon

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“…A relatively enlarged telencephalon, as reported in members of Carcharhinidae and Sphyrnidae , has been associated with species that live in complex habitats and the social interactions that occur in those habitats [Striedter, 2005], similarly documented in other vertebrate groups [Riddell and Corl, 1977;Huber et al, 1997;Pollen et al, 2007;Shumway, 2008]. In particular, development of the central nucleus has been linked to complex social behaviors such as dominance hierarchies and other forms of 'social intelligence' [Cohen et al, 1973;Graeber, 1978;Graeber et al, 1978;Demski and Northcutt, 1996]. An enlarged central nucleus of the dorsal pallium has been recorded in Cetorhinus maximus [Kruska, 1988], although was described as being less developed than that of R. typus [Sato, 1986].…”

Section: General Brain Organizationmentioning

confidence: 99%

Brain Size and Brain Organization of the Whale Shark, Rhincodon typus, Using Magnetic Resonance Imaging

Yopak

Frank²

2009

Brain Behav Evol

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Very little is known about the brain organization of the suction filter feeder, Rhincodon typus, and how it compares to other orectolobiforms in light of its specialization as a plankton-feeder. Brain size and overall brain organization was assessed in two specimens of R. typus in relation to both phylogeny and ecology, using magnetic resonance imaging (MRI). In comparison to over 60 other chondrichthyan species, R. typus demonstrated a relatively small brain for its body size (expressed in terms of encephalization quotients and residuals), similar to the lamniforms Carcharodon carcharias, Cetorhinus maximus, and Carcharias taurus. R. typus possessed a relatively small telencephalon with some development of the dorsal pallium, which was suggestive of moderate social behavior, in addition to a relatively large diencephalon and a relatively reduced mesencephalon. The most notable characteristic of the brain of Rhincodon was a large and highly foliated cerebellum, one of the largest cerebellums within the chondrichthyan clade. Early development of the brain was qualitatively assessed using an in situ MRI scan of the brain and chondrocranium of a neonate specimen of R. typus. There was evidence that folding of the cerebellar corpus appeared in early development, although the depth and number of folds might vary ontogenetically in this species. Hierarchical cluster analysis and multidimensional scaling ordinations showed evidence of convergent evolution with the basking shark, Cetorhinus maximus, another large-bodied filter feeding elasmobranch, supporting the claim that organization of the brain is more similar in species with analogous but independently evolved lifestyles than those that share taxonomic classification.

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Electrophysiological Identification of a Visual Area in Shark Telencephalon

Cited by 88 publications

References 7 publications

Organization of Major Telencephalic Pathways in an Elasmobranch, the Thornback Ray <i>Platyrhinoidis triseriata</i>

Organization of Major Telencephalic Pathways in an Elasmobranch, the Thornback Ray <i>Platyrhinoidis triseriata</i>

The Fish Telencephalon and Its Relation to Learning

Brain Size and Brain Organization of the Whale Shark, <i>Rhincodon typus</i>, Using Magnetic Resonance Imaging

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