November 17, 2010 12:03 PM PST
Human brain has more switches than all computers on Earth
by Elizabeth Armstrong Moore
This is a visual reconstruction from array-tomography data of synapses in the mouse somatosensory cortex, which is responsive to whisker stimulation.
(Credit: Stephen Smith/Stanford)
The human brain is truly awesome.
A typical, healthy one houses some 200 billion nerve cells, which are connected to one another via hundreds of trillions of synapses. Each synapse functions like a microprocessor, and tens of thousands of them can connect a single neuron to other nerve cells. In the cerebral cortex alone, there are roughly 125 trillion synapses, which is about how many stars fill 1,500 Milky Way galaxies.
These synapses are, of course, so tiny (less than a thousandth of a millimeter in diameter) that humans haven't been able to see with great clarity what exactly they do and how, beyond knowing that their numbers vary over time. That is until now.
Researchers at the Stanford University School of Medicine have spent the past few years engineering a new imaging model, which they call array tomography, in conjunction with novel computational software, to stitch together image slices into a three-dimensional image that can be rotated, penetrated and navigated. Their work appears in the journal Neuron this week.
To test their model, the team took tissue samples from a mouse whose brain had been bioengineered to make larger neurons in the cerebral cortex express a fluorescent protein (found in jellyfish), making them glow yellow-green. Because of this glow, the researchers were able to see synapses against the background of neurons.
...
Read more here/Leia mais aqui: CNET
Mero acaso, fortuita necessidade ou sinais detectados de design inteligente???
+++++
Single-Synapse Analysis of a Diverse Synapse Population: Proteomic Imaging Methods and Markers
Neuron, Volume 68, Issue 4, 639-653, 18 November 2010
Copyright 2010 Elsevier Inc. All rights reserved.
10.1016/j.neuron.2010.09.024
Authors
Kristina D. Micheva,Brad Busse,Nicholas C. Weiler,Nancy O'Rourke,Stephen J SmithSee Affiliations
Highlights
Resolution of individual synapses in situ by high-throughput array tomography
Measurement of multiple (e.g., 17) molecular markers at individual synapses
Discrimination of defined subtypes of glutamate and GABA synapses
Detection of both VGluT1-type glutamate and GABA synapses on single spines
Summary
A lack of methods for measuring the protein compositions of individual synapses in situ has so far hindered the exploration and exploitation of synapse molecular diversity. Here, we describe the use of array tomography, a new high-resolution proteomic imaging method, to determine the composition of glutamate and GABA synapses in somatosensory cortex of Line-H-YFP Thy-1 transgenic mice. We find that virtually all synapses are recognized by antibodies to the presynaptic phosphoprotein synapsin I, while antibodies to 16 other synaptic proteins discriminate among 4 subtypes of glutamatergic synapses and GABAergic synapses. Cell-specific YFP expression in the YFP-H mouse line allows synapses to be assigned to specific presynaptic and postsynaptic partners and reveals that a subpopulation of spines on layer 5 pyramidal cells receives both VGluT1-subtype glutamatergic and GABAergic synaptic inputs. These results establish a means for the high-throughput acquisition of proteomic data from individual cortical synapses in situ.
+++++
Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo da Neuron e de mais 22.440 publicações científicas.
+++++
NOTA CAUSTICANTE DESTE BLOGGER:
Fui, sabendo cada vez mais por que a decrépita e falida teoria da evolução através da seleção natural de Darwin, que não consegue explicar a origem e evolução de um simples flagelo bacteriano, não tem, NOTA BENE, não tem capacidade heurística de explicar a origem e evolução do cérebro.
QED: Se não tem esta robustez epistêmica, a teoria é frágil porque encontrada despida no contexto de justificação teórica.
O que temos nesta área evolutiva não é ciência, é ALQUIMIA!!! Pode evoluir em ciência como a alquimia evoluiu em química, mas ainda é ALQUIMIA OU METAFÍSICA PURA!!!
QED: Se não tem esta robustez epistêmica, a teoria é frágil porque encontrada despida no contexto de justificação teórica.
O que temos nesta área evolutiva não é ciência, é ALQUIMIA!!! Pode evoluir em ciência como a alquimia evoluiu em química, mas ainda é ALQUIMIA OU METAFÍSICA PURA!!!
