HNPP therefore appears to represent a reciprocal product of Charcot-Marie-Tooth disease type 1A (CMT1A), which is associated with duplication of PMP22.10 PMP22 is an important factor for regulation of Schwann cell proliferation and apotosis.1
via MeFi:
A naive Quora question gets a remarkably long, thorough answer from an anonymous respondent. The answer cites, among many other things, Tim Gowers’s influential essay “The Two Cultures of Mathematics,” about the tension between problem-solving and theory-building. Related: Terry Tao asks “Does one have to be a genius to do maths?”
Human Subway Map - by sam loman
Spiking Neural Networks (SNNs)
Apparently ANN’s have been at an impasse. Maybe SNN’s will be more promising. Some resources:
on an aside, here’s a place for neuroscientists from all disciplines to share data and ideas : http://crcns.org/
Neural Network Resources
http://pyneurgen.sourceforge.net/index.html
Tutorial for programming hand-written image recognition.
IBM DeveloperWorks Intro to Neural Networks
IBM’s DevWorks Weave a Neural Net with Python
Simple Neural Network in Python
Artificial Intelligence: A Modern Approach
Hubs in the brain. How does brain coordinate multiple activities in unison?
How is the brain is able to coordinate multiple activities in unison? Highly connected hub neurons or hub neural centers play a role in synchronizing neural activity. Here are some good reads:
1) GABAergic Hub Neurons Orchestrate Synchrony in Developing Hippocampal Networks
P. Bonifazi et al,
via Science Mag
Abstract:
Brain function operates through the coordinated activation of neuronal assemblies. Graph theory predicts that scale-free topologies, which include “hubs” (superconnected nodes), are an effective design to orchestrate synchronization. Whether hubs are present in neuronal assemblies and coordinate network activity remains unknown. Using network dynamics imaging, online reconstruction of functional connectivity, and targeted whole-cell recordings in rats and mice, we found that developing hippocampal networks follow a scale-free topology, and we demonstrated the existence of functional hubs. Perturbation of a single hub influenced the entire network dynamics. Morphophysiological analysis revealed that hub cells are a subpopulation of {gamma}-aminobutyric acid–releasing (GABAergic) interneurons possessing widespread axonal arborizations. These findings establish a central role for GABAergic interneurons in shaping developing networks and help provide a conceptual framework for studying neuronal synchrony.
2) Mapping the Structural Core of Human Cerebral Cortex
via PLoS
NY Times reporting on the paper.
3) The Neural Architecture of Music-Evoked Autobiographical Memories. Petr Janata.
via Cerebral Cortex
Science Daily reporting on paper.
Are there “flip flops” and “gates” in neural circuit?
- Are memory traces networks that oscillate?
- Look up oscillating EEG activity?
Flow in the Brain
- Sensory circuit tracing flows into appropriate motor or sensory or other tracing. What would be other tracings?
- Goals, beliefs, values have both stimulatory and inhibitory activity which guides the flow.
- There are simultaneous unconscious and conscious flows. Why are we “conscious” of only one flow at a time?
Pathologic Flow in the Brain
- Why/How/When did Flow evolve?
—To allow one or more parts of the body to respond appropriately to a sensory stimuli.
Reflection of activity
- Output activity from neuron source can take many different forms, have different reflections. Like a hologram?
Godel, Escher, Kurt Hasley?
Godel Escher Bach on XKCD. It’s profound and beautiful.
GEB in a Nutshell
After spending a few years clawing through the book, I’ve finally reached a slightly pathetic understanding of what the hell he is weaving Godel’s Incompleteness Theorem, Bach, Typographical Numbering Theory, Zen, etc… etc… etc… all into. For anyone else who has recently found themselves blowing dust off the covers of this bear of a book, I’d recommend skipping ahead to the Chapter: Levels of Description, and Computer Systems. For the computer inclined out there, it provides a foothold from which to grasp a hold of the rest of the book.
Some Observations from GEB
- Chunking: The nuclear physicist has a chunked understanding of protons, neutrons, quarks. The atomic physicist has a chunked picture of nucleus, electron orbitals. The molecular biologist has a chunked picture of these units. Ergo the cell biologist, the doctor…
- There is a trade-off b/n chunking and determinism - Our models of lower chunks can only give us probabilistic estimates of how those chunks will act.
Systems and Chunking
- “Systems whose subsystems can be reliably predicted from chunked descriptions play important roles in our lives because they are pillars of stability” -GEB 307
Epiphenomena
- Where is 100 M / 9.3 sec stored in Usain Bolt’s brain? “It is a visible consequence of the overall system organization - i.e. an epiphenomenon.
- Is there a gullibility center in your brain?
