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Birds have primate-like numbers of neurons in the forebrain.; Seweryn Olkowicz, et. al. PNAS, June 13, 2016 DOI: 10.1073/pnas.1517131113
Topic Started: Jun 14 2016, 06:46 PM (987 Views)
Taipan
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Journal Reference:
Seweryn Olkowicz, Martin Kocourek, Radek K. Lučan, Michal Porteš, W. Tecumseh Fitch, Suzana Herculano-Houzel, and Pavel Němec. Birds have primate-like numbers of neurons in the forebrain. PNAS, June 13, 2016 DOI: 10.1073/pnas.1517131113

Abstract
Some birds achieve primate-like levels of cognition, even though their brains tend to be much smaller in absolute size. This poses a fundamental problem in comparative and computational neuroscience, because small brains are expected to have a lower information-processing capacity. Using the isotropic fractionator to determine numbers of neurons in specific brain regions, here we show that the brains of parrots and songbirds contain on average twice as many neurons as primate brains of the same mass, indicating that avian brains have higher neuron packing densities than mammalian brains. Additionally, corvids and parrots have much higher proportions of brain neurons located in the pallial telencephalon compared with primates or other mammals and birds. Thus, large-brained parrots and corvids have forebrain neuron counts equal to or greater than primates with much larger brains. We suggest that the large numbers of neurons concentrated in high densities in the telencephalon substantially contribute to the neural basis of avian intelligence.

http://www.pnas.org/content/early/2016/06/07/1517131113
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Cape Leopard
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So if these birds were to later have descendants that became terrestrial and evolved to a size similar to humans, they would probably have genius-level intellect, if their brain remains the same and all other things being equal
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Shin
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Cape Leopard
Jun 15 2016, 12:45 AM
So if these birds were to later have descendants that became terrestrial and evolved to a size similar to humans, they would probably have genius-level intellect, if their brain remains the same and all other things being equal
It is there flying ability that fosters such a necessity
for having cognitive abilities that process information
at a much faster rate than other animals...

Birds can detect & react faster to outside stimuli
b/c of this...it isn't the same as having the
capacity for problem solving; all birds are not
as intelligent as a Raven, but most avian species process
information much faster than most other
vertebrates...they are also much better at detecting subtle
shifts in behavior & body language as many species can
differentiate between a hunting raptor vs one that isn't intent
on securing prey & can react accordingly...


Edited by Shin, Jun 15 2016, 10:05 AM.
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Taipan
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Birds and primates share brain cell types linked to intelligence

February 15, 2018, University of Chicago Medical Center

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Neuronal cell types in the brains of birds linked to goal-directed behaviors and cognition are similar to cells in the mammalian neocortex, the large, layered structure on the outer surface of the brain where most higher-order processing takes place.

In a new study, published this week in the journal Current Biology, scientists from the University of Chicago show that some neurons in bird brains form the same kind of circuitry and have the same molecular signature as cells that enable connectivity between different areas of the mammalian neocortex. The researchers found that alligators share these cell types as well, suggesting that while mammal, bird and reptile brains have very different anatomical structures, they operate using the same shared set of brain cell types.

"Birds are more intelligent than you think, and they do clever things. So, the question is: What kind of brain circuitry are they using?" said Clifton Ragsdale, PhD, professor of neurobiology at UChicago and senior author of the study. "What this research shows is that they're using the same cell types with the same kinds of connections we see in the neocortex, but with a very different kind of organization."

Both the mammalian neocortex and a structure in the bird brain called the dorsal ventricular ridge (DVR) develop from an embryonic region called the telencephalon. However, the two regions mature into very different shapes. The neocortex is made up of six distinct layers while the DVR contains large clusters of neurons called nuclei.

Because of this different anatomy, many scientists proposed that the bird DVR does not correspond to the mammalian cortex but is instead analogous to another mammalian brain structure called the amygdala.

In 2012, Ragsdale and his team confirmed a 50-year-old hypothesis by University of California San Diego neuroscientist Harvey Karten that proposed the DVR performs a similar function to the neocortex, but with dramatically different anatomy. In that study, the UChicago researchers matched genetic markers of the "input" and "output" neurons of the mammalian neocortex with genes expressed in several bird DVR nuclei.

In the new study, led by graduate student Steven Briscoe, the team found that other populations of neurons in the bird DVR share molecular signatures with neocortical intratelencephalic cells, or IT neurons. These IT neurons form a critical link in the circuitry of the neocortex. They help communicate between different neocortical layers and across cortical areas from one side of the brain to the other. The team then extended their work from birds to reptiles and identified IT neurons in a similar place in the alligator DVR.

"The structure of the avian DVR looks nothing like the mammalian neocortex, and this has historically been a huge problem in comparative neuroscience," Briscoe said. "Anatomists have debated how to compare the DVR and neocortex for over a century, and our identification of IT neurons in the bird DVR helps to explain how such different brain structures can give rise to similar behaviors."

The research suggests an interesting possibility that birds and primates evolved intelligence independently, developing vastly different brain structures but starting with the same shared sets of cell types.

"The input cell types, the output cell types and the intratelencephalic cell types are all conserved. They're not just found in mammals, which we knew, but in non-avian reptiles like alligators and avian reptiles, or birds," Ragsdale said. "It begins to clarify where and how in evolution we got this fantastic structure, the neocortex."

https://phys.org/news/2018-02-birds-primates-brain-cell-linked.html




Journal Reference:
Clifton W. Ragsdale. Neocortical Association Cell Types in the Forebrain of Birds and Alligators. Current Biology, 2018; DOI: 10.1016/j.cub.2018.01.036

Highlights
• RNA-seq identifies neocortical intratelencephalic (IT) neurons in the avian brain
• IT neurons populate the avian mesopallium but not the nidopallium or the arcopallium
• Gene expression demonstrates IT cell types in the alligator dorsal telencephalon
• IT neurons were present in the last common ancestor of birds and mammals
Summary
The avian dorsal telencephalon has two vast territories, the nidopallium and the mesopallium, both of which have been shown to contribute substantially to higher cognitive functions. From their connections, these territories have been proposed as equivalent to mammalian neocortical layers 2 and 3, various neocortical association areas, or the amygdala, but whether these are analogies or homologies by descent is unknown. We investigated the molecular profiles of the mesopallium and the nidopallium with RNA-seq. Gene expression experiments established that the mesopallium, but not the nidopallium, shares a transcription factor network with the intratelencephalic class of neocortical neurons, which are found in neocortical layers 2, 3, 5, and 6. Experiments in alligators demonstrated that these neurons are also abundant in the crocodilian cortex and form a large mesopallium-like structure in the dorsal ventricular ridge. Together with previous work, these molecular findings indicate a homology by descent for neuronal cell types of the avian dorsal telencephalon with the major excitatory cell types of mammalian neocortical circuits: the layer 4 input neurons, the deep layer output neurons, and the multi-layer intratelencephalic association neurons. These data raise the interesting possibility that avian and primate lineages evolved higher cognitive abilities independently through parallel expansions of homologous cell populations.

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SuetheRex
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Those studies are also important because it's effectively studing avian dinosaur brain. From those datas we can better understand the true capabilities of the dinosaur brain area that was dedicated to complex thinking (such as the ones found in Raptors and Tyrannosaurus Rex)
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