The classic model of how brain cells communicate was put forth in 1943 by Warren McCulloch and Walter Pitts, at the time the first digital computers were being envisaged, and the McCulloch-Pitts model suggested that brain cells communicate in a binary fashion, represented by a “1” for firing and a “0” for not firing, much as a modern computer functions.

While it is common to say that a mammalian brain functions like a computer, this is a somewhat faulty idea, in part because the observation from the Traub lab suggests that gap junctions cause “short circuiting” as part of the brain’s normal functions. A real computer could not function if it short circuited. It is possible that these short circuits in the mammalian brain generally enhance brain function and adaptation to the environment, such as by permitting creative thinking, the combining of isolated facts into new ideas.

Researchers have found strong evidence for a novel type of communication between nerve cells in the brain. The findings may have relevance for the prevention and treatment of epilepsy, and possibly in the exploration of other aspects of brain functions, from creative thought processes to mental illnesses such as schizophrenia.

How social or altruistic behavior evolved has been a central and hotly debated question, particularly by those researchers engaged in the study of social insect societies of ants, bees and wasps.

In these groups, this question of what drives altruism also becomes critical to further understanding of how ancestral or primitive social organizations (with hierarchies and dominance fights, and a poorly developed division of labor) evolve to become the more highly sophisticated networks found in some eusocial insect collectives called “superorganisms.”

A pair of researchers from Cornell University and ASU proposed a model, based on a tug-of-war theory, that may explain the selection pressures that mark the evolutionary transition from primitive society to superorganism – and which may bring some order to the conflicted thinking about the roles of individual, kin and group selection that underlie the formation of such advanced eusocial groups.

A superorganism ultimately emerges as a result of intergroup competition, according to findings by theoretician H. Kern Reeve of Cornell University’s Department of Neurobiology and Behavior and professor Bert Hölldobler of ASU’s School of Life Sciences and Center for Social Dynamics and Complexity.

Reeve and Hölldobler’s model is unique in that it comprises two interlocked, nested tug-of-war theories. The first piece describes the tug-of-war over resources within a group or colony (intragroup competition), and the second piece incorporates the effects of a tug-of-war between competing colonies (intergroup competition).

According to Hölldobler, the path to colonial supergiant is first paved by the maximization of the inclusive fitness of each individual of the society. How this might arise, he believes, is that competition that might exist between individuals in the same society diminishes as the incipient colonial society becomes larger, better organized and contains better division of labor – and, ultimately, better cohesiveness.

“Such societies, in turn, produce more reproductive offspring each year than neighboring societies that are less organized,” Hölldobler says. “Thus, genes or alleles that code for such behaviors will be propagated faster.”

The second piece of the model takes into account that “as the colonial organization of one group rises, there is a coincident rise in discrimination against members of other societies of the same species.”

Hölldobler notes that the competition between societies soon becomes a major force reinforcing the evolutionary process, saying: “In this way, the society or insect colony becomes the extended phenotype of the collective genome of the society.”

Hölldobler believes that this model developed with Reeve goes further than others in explaining the evolutionary transition from hierarchical organizations to superorganism, “as it also demonstrates how the target of selection shifts from the individual and kin to group selection,” he says.

Such a nested tug-of-war model, he says, might also be applied “equally well to the analysis of the evolution of other animal societies” and give insight into the evolution of cooperation in non-human and human primates, in addition to such things as collectives of cells and the formation of bacterial films.

Hölldobler is the Pulitzer Prize-winning author (1991, nonfiction) of “The Ants,” co-authored with Edward O. Wilson, Harvard professor emeritus. Hölldobler’s research on the evolution of social organizations for this tiny, formidable insect has taken him around the world, led to the authorship of more than 300 articles and has garnered many international awards, including the Treviranus Medal, the U.S. Senior Scientist Prize and the Werner Heisenberg-Medal of the Alexander von Humboldt Foundation, and the Gottfried Wilhelm Leibniz Prize, some of the most prestigious science prizes given in Europe.

Hölldobler has been elected to the National Academy of Sciences, the American Academy of Arts and Sciences, the American Philosophical Society, and he is the former Alexander Agassiz Professor of Zoology of Harvard University and professor emeritus of the University of Würzburg, Germany.

In addition to being a professor in the School of Life Sciences and the Center for Social Dynamics and Complexity in the College of Liberal Arts and Sciences at ASU, he also is Cornell University’s Andrew D. White Professor at Large.

Source: ASU

A critical step in brain development is governed by endogenous cannabinoids, the brain’s own marijuana. Studies conducted at Swedish medical university Karolinska Institutet, with participation of scientists from Europe and the United States, are now published in Science and show that these endogenous molecules regulate how certain nerve cells recognize each other and form connections. The scientists believe that their findings will significantly advance our understanding of how cannabis smoking during pregnancy may damage the fetal brain.

For nearly a century, anthropologists have been debating the relationship of Neanderthals to modern humans. Central to the debate is whether Neanderthals contributed directly or indirectly to the ancestry of the early modern humans that succeeded them.

As this discussion has intensified in the past decades, it has become the central research focus of Erik Trinkaus, Ph.D., professor of anthropology at Washington University in St. Louis. Trinkaus has examined the earliest modern humans in Europe, including specimens in Romania, Czech Republic and France. Those specimens, in Trinkaus’ opinion, have shown obvious Neanderthal ancestry.

In an article appearing the week of April 23 in the Proceedings of the National Academy of Sciences, Trinkaus has brought together the available data, which shows that early modern humans did exhibit evidence of Neanderthal traits.

“When you look at all of the well dated and diagnostic early modern European fossils, there is a persistent presence of anatomical features that were present among the Neanderthals but absent from the earlier African modern humans,” Trinkaus said. “Early modern Europeans reflect both their predominant African early modern human ancestry and a substantial degree of admixture between those early modern humans and the indigenous Neanderthals.”

This analysis, along with a number of considerations of human genetics, argues that the fate of the Neanderthals was to be absorbed into modern human groups. Just as importantly, it also says that the behavioral difference between the groups were small. They saw each other as social equals.

Source: Washington University in St. Louis.