Some further implications of the brain=behavior notion
- Brains "sort of the same" but sort of different in different people
- Brains "sort of the same" but sort of different in one person at different times
|Interesting. Maybe individuality and "learning"
make sense this way? The brain isn't something you're born with that never changes, and its different in every person? But also similar in different people and somehow similar through time in one person? Wonder how that could be?
Elaborating the nervous system as input-output box model
Some relevant web references, for Feb 1,3:
Divisions of the nervous system
Comparative Neuroanatomy (mammalian)
Invertebrate Nervous Systems
Comparative Mammalian Brain Collections
The Whole Brain Atlas
Leech Neurobiology Newsletter
Global Anatomy, includes neuroscience and histology units, resources
Types of Nerve Cells
Gallery of Neurons
Interconnected boxes within boxes within boxes
- "Its boxes all the way down"
- The neuron as the smallest box we'll work with
- Substantial similarities in the neurons in the different larger boxes
- No special "neocortex" or "spinal cord" neuron
|You know, this isn't quite the way I heard about this stuff before. What about what all the stuff about what the bigger boxes DO? How come we skipped over that? You know, I never thought before that in some sense all the bigger boxes are made up of more or less the same smaller boxes. Wonder if that's really true? If so, how can the bigger boxes do different things?
|The neuron as an input/output box |
- Soma = cell body
- Dendritic processes = receiving areas, input
- Axonal processes = transmitting areas, output
- Soma small (microns), but processes (particularly axon) can be very long (up to meters)
|Some implications of discovering neurons
Some forum thoughts:
Picking up neurons as smallest boxes:
- Culture/upbringing - consistent with box model?
- IF brain constantly changing based on interactions with outside world
- Mostly interneurons?
- Use only part of brain?
- paper topic?
- Are all neurons "pretty much the same"?
- could be - neutrons, protons, electrons differently arranged
- but .... will see
Need to understand neurons, signals, inputs/outputs
- Mammalian, vertebrate, invertebrate nervous systems just different arrangements of neurons
- Can signals start inside boxes?
Some relevant web references, for Feb 8-17:
Finding the "signal" that neurons use - the action potential
- Evidence from motoneuron axon, muscle, light bulbs
- External, longitudinal, transient, constant amplitude, moving battery
|You know, he's doing it AGAIN. I LEARNED about action potentials already, and there weren't any BATTERIES. Where did these BATTERIES come from? Why can't he just talk about this stuff the NORMAL way, instead of throwing in all these things that confuse me?|
This diffusion thing, though, that's kind of interesting. Things always in motion (no "first mover"), random motion gives direction, maybe organization? Have to think more about that.
The resting potential as a way to understand the action potential
- Light bulb evidence
- Constant, transmembrane battery
- Diffusion as a deep physical reality
- Diffusion of ions down concerntration gradients with differential permeabilities to different ions yields stable battery
- No significant change in concentration gradient
- Gradient exists because of independent process - pump
- Lots of different possible batteries depending on relative permeabilities to different ions
- Resting potential largely due to high internal potassium and high relative permeability for potassium
Basic Neural Processes
The Virtual Neurophysiology Lab
From Random Motion to Order: Diffusion and Some of its Implications
|From the resting potential to the action potential
Some forum thoughts:
- If its "all chemicals", can all behavior be "corrected" by injecting chemicals?
- The levels of organization issue - is not JUST "chemicals", is highly organized chemicals, at several successive levels of organization
- Small frontal lobes in people with persistant "criminal" behavior? - NY Times, Tuesday, 15 Feb
- The "normal" issue - how does one decide what should be "corrected", what not?
- Brains causing changes in other brains not novel or unusual - childrearing, education, etc all longstanding ways to "change" brains, and presumably to change organization of "chemicals"
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