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G M Edelman

Publications and source records attributed to G M Edelman.

At least 379 records · Page 21Linked to original sources
PubMed1966

Polypeptide chains of immunoglobulins from the smooth dogfish (Mustelus canis).

The 17S and 7S immunoglobulins of the smooth dogfish, Mustelus canis, have been characterized with respect to molecular weights, chain structure, amino acid composition, and carbohydrate content. The 17S protein had a molecular weight of 982,000; that of the 7S protein was 198,000. Both proteins had similar amino acid compositions and a carbohydrate content of approximately 8 percent. Light and heavy chains from both immunoglobulins had molecular weights of 20,000 and 72,000 respectively. Apparently both immunoglobulins belong to the same class; this class resembles the gammaM-immunoglobulins of higher vertebrates.

Amino Acids↗
PubMed1966

Phylogenetic origins of antibody structure. II. Immunoglobulins in the primary immune response of the bullfrog, Rana catesbiana.

The anuran amphibian, Rana catesbiana, has been found to possess at least two kinds of immunoglobulins corresponding to gammaG- and gammaM-classes. These classes have the same chain structures as those of their counterparts in higher animal species. Light chains of both immunoglobulins had molecular weights of 20,000. Heavy chains of the gammaM-class had molecular weights of 72,100; those of the gammaG-class had molecular weights of 53,600. The carbohydrate content of the gammaG-immunoglobulin was 2.1%, and that of the gammaM-protein was 10.8%. The amino acid compositions of the immunoglobulins were generally similar to those of mammalian immunoglobulins. After a single injection of phage antigen (f2), the order of appearance of phage-neutralizing activity in the frog immunoglobulin classes was (a) gammaM-antibodies, and (b) gammaG-antibodies. The results of this and previous studies suggest that the gammaG-immunoglobulins emerged at some point in evolution between the elasmobranchs and the anuran amphibians.

Animals↗
PubMed1965

Phylogenetic origins of antibody structure. I. Multichain structure of immunoglobulins in the smooth dogfish (Mustelus canis).

The elasmobranch Mustelus canis has been shown to produce antibodies to Limulus hemocyanin. The serum of both normal and immunized M. canis contains immunoglobulins having sedimentation coefficients of approximately 7S and 17S. Antibody activity was found in the 17S immunoglobulin which may be dissociated to 7S components with concomitant loss of activity. Both 17S and 7S serum, immunoglobulins were antigenically identical. They consisted of light and heavy chains present in amounts comparable to those of higher vertebrates. Peptide maps indicated that the light chains had an entirely different primary structure than the heavy chains, but that the corresponding chains of 7S and 17S dogfish serum immunoglobulins were similar in primary structure. The heavy chains appeared to resemble the n chains of immunoglobulins of higher vertebrates in their starch gel electrophoretic behavior. It is suggested that the elasmobranch M. canis may have only one major class of immunoglobulins resembling that of macroglobulins (gammaM-immunoglobulins) seen in higher vertebrates. The results indicate that the multichain structure of antibodies is an ancient evolutionary development.

Animals↗
PubMedDate not supplied

Connectivity and complexity: the relationship between neuroanatomy and brain dynamics.

Nervous systems facing complex environments have to balance two seemingly opposing requirements. First, there is a need quickly and reliably to extract important features from sensory inputs. This is accomplished by functionally segregated (specialized) sets of neurons, e.g. those found in different cortical areas. Second, there is a need to generate coherent perceptual and cognitive states allowing an organism to respond to objects and events, which represent conjunctions of numerous individual features. This need is accomplished by functional integration of the activity of specialized neurons through their dynamic interactions. These interactions produce patterns of temporal correlations or functional connectivity involving distributed neuronal populations, both within and across cortical areas. Empirical and computational studies suggest that changes in functional connectivity may underlie specific perceptual and cognitive states and involve the integration of information across specialized areas of the brain. The interplay between functional segregation and integration can be quantitatively captured using concepts from statistical information theory, in particular by defining a measure of neural complexity. Complexity measures the extent to which a pattern of functional connectivity produced by units or areas within a neural system combines the dual requirements of functional segregation and integration. We find that specific neuroanatomical motifs are uniquely associated with high levels of complexity and that such motifs are embedded in the pattern of long-range cortico-cortical pathways linking segregated areas of the mammalian cerebral cortex. Our theoretical findings offer new insight into the intricate relationship between connectivity and complexity in the nervous system.

Animals↗