Biology 202
Neurobiology and Behavior
Spring 2003

Forum Archive - Week 7

We've pretty much got straight the fundamental properties of neurons and their ways of talking to one another (action potentials both triggered and autonomous, integration of currents due to permeability changes, sending of signals via chemical intermediaries, etc). And we know there are LOTS of them organized by both anatomical and chemical specificities. So ... is that ENOUGH? Can we get all of behavior and human experience out of that? What would we need to do? What stands in the way?


Name:  Sarah
Username:  Anonymous
Subject:  News on Reeve
Date:  2003-03-14 10:52:44
Message Id:  5012
Comments:

I thought this was interesting medically, and while it doesn't really pertain to NB&B, it is about one of our favorite examples, Christopher Reeve.

Here is a NY Times article, posted below so you don't have to sign in:

Reeve Smelling the Coffee Again, and More
By THE NEW YORK TIMES

CLEVELAND, March 13 — The actor Christopher Reeve, who can breathe on his own for 15-minute stretches after experimental surgery to implant electrodes that stimulate the muscles in his diaphragm, told reporters today that he had just had a remarkable experience.

Breathing through his nose, instead of through the hole in his throat required by his ventilator, Mr. Reeve was able to identify various smells — an orange, a chocolate-chip cookie, a mint and coffee — for the first time in the eight years since a horseback riding accident left him paralyzed from the neck down.

"I actually woke up and smelled the coffee," he told a news conference at University Hospitals of Cleveland, where the operation was performed on Feb. 28.

During another 15-minute session off the ventilator, he said, he asked his support staff to turn off the machine so he could enjoy the silence. That was when he heard the sound of his own breathing.

"That meant a tremendous amount," he said.

While his doctors say they hope he can wean himself permanently from the respirator, Mr. Reeve still needs it for most of the day, and he used it throughout today's news conference.

"This necktie I'm wearing is not my favorite," he said of the tube hanging from the hole in his neck.

Two of his doctors, Anthony DiMarco and Raymond Onders, the surgeon who performed the operation, told reporters that its full effects would not be known for two to three months. In that time, Mr. Reeve will undergo conditioning exercises several times a day to retrain his atrophied diaphragm.

Every time the electrodes stimulate his diaphragm to contract, Reeve, 50, said, he feels a sensation like "a mild little flick of the finger," which is not uncomfortable.

Mr. Reeve plans to incorporate the exercises into his overall physical-therapy regimen, which includes water therapy and working out on a special bicycle. The program has enabled him to wiggle his extremities, to sit up partly by himself and, before he had the implant, to use his neck muscles to breathe for short periods without a respirator.

But he will continue to need critical-care supervision 24 hours a day.

"It is an exciting moment but also one that has to be put into perspective in terms of what rehabilitation really is," he said. "It's a process. It takes discipline and it takes time and it also takes a tremendous support system." He continued, "No one knows when or even if this will be successful," he continued. "But I'm a pretty determined individual."


Name:  Sarah
Username:  Anonymous
Subject:  computers
Date:  2003-03-14 10:59:51
Message Id:  5013
Comments:
I question Prof. Grobstein's assertion that brains are not like computers, simply because every neuron is a CPU (Central Processing Union). To me, that seems to make the brain a supercomputer, not a non-computer. It increases the complexity a millionfold (10^15-fold!), but it really doesn't seem to make the analogy invalid.
Name:  Sarah
Username:  Anonymous
Subject:  typo
Date:  2003-03-14 11:00:57
Message Id:  5014
Comments:
woops... CPU is central processing unit, not union.
Name:  Alanna Albano
Username:  ajalbano@brynmawr.edu
Subject:  brain/behavior
Date:  2003-03-15 14:13:27
Message Id:  5016
Comments:
The action potentials of the nervous system do make it easier to understand and accept that brain=behavior. Action potentials, membrane permeabilities, and ionic gradients are responsible for coding membrane proteins by DNA. Since we know that DNA and genes do influence our behavior, then the action potentials of the nervous system must influence our behavior as well. Therefore, it should be obvious that a dysfunctional mechanism within the action potential system will ultimately affect behavior. The more severe this dysfunction is within the system, the more drastic the change is in the behavior of the person. For example, a disruption in action potential signals could severely affect nervous system output, such as walking or another motor skill.
Name:  Paul Grobstein
Username:  pgrobste@brynmawr.edu
Subject:  getting back in gear
Date:  2003-03-16 19:07:14
Message Id:  5017
Comments:
Welcome back. Hope everybody had a good spring break AND kept thinking about brain/behvavior. Happy to hear whatever you've been thinking, but here's the challenge I left you with the last time we were together ...

We've pretty much got straight the fundamental properties of neurons and their ways of talking to one another (action potentials both triggered and autonomous, integration of currents due to permeability changes, sending of signals via chemical intermediaries, etc). And we know there are LOTS of them organized by both anatomical and chemical specificities. So ... is that ENOUGH? Can we get all of behavior and human experience out of that? What would we need to do? What stands in the way?


Name:  Danielle McManus
Username:  dmcmanus@brynmawr.edu
Subject:  
Date:  2003-03-16 19:56:33
Message Id:  5018
Comments:
What I'd like to get a better grasp of is where personality fits into the model. If our brain is where behavior is generated and behavior is controlled by neurons with all their membranes, ionic gradients, neurotransmitters, etc., how are our personalities formed and expressed? Are we pre-programed with certain membrane permeabilities that translate into, say, naturally chipper dispositions? How are our neural behavioral mechanisms affected by environment? If we're raised to suppress a natural giddiness and subsequently display a very austere personality, have our neurons or their patterns of operation been altered?
Name:  Amelia
Username:  aturnbul@brynmawr.edu
Subject:  
Date:  2003-03-16 20:13:09
Message Id:  5019
Comments:
I would like to say that there something more in the human experience than what can be explained by neurons and how they communicate with each other. Since I am taking this class to learn more about this subject, I don't know that much about it, but I would like to know more about creativity and creative reasoning and how that fits into neuroscience. I do know that about 40,000 years ago (if I'm remembering correctly - it could be a bit longer ago than that) there was a creative revolution among our species. Until this point, we were using the same technology as the Neanderthals and unless archaeologists find some human remains, there is no really good way to determine whether the site was habitated by humans or Neanderthals. Then, 40,000 years ago, the "creative revolution" hit and archaeologists and anthropologists are able to see a marked differentiation between the technology, etc. of the two species. Maybe, about 40,000 years ago, a creative type of human was selected for.
Name:  Kelvey
Username:  krichard@brynmawr.edu
Subject:  magnetism and the brain
Date:  2003-03-17 10:45:23
Message Id:  5021
Comments:
I realize that a question about the existence of magnitism has been brought up in class so I found it interesting to learn that one of the most rapidly developing non-invasive tools for studying the human brain is transcranial magnetic stimulation (TMS). TMS provides a pulsed magnetic field which creates current flow in the brain and can temporarily excite or inhibit specific areas. Some of the interesting points that were made in the July 13, 2000 Nature article on TMS was on brain plasiticity and that there appears to be a constant battle for the control of each neuron among its various inputs. My question is what determines the winner of the battle between neurons. Besides action potential, what controls the passage of a input and in what areas can that input be disrupted?
Name:  geoff
Username:  gpollitt@haverford.edu
Subject:  memory...
Date:  2003-03-17 12:24:37
Message Id:  5022
Comments:
we haven't talked much about memory yet, but this short article is worth a look. its about watching memories being formed in the neurons of a mouse. its creepy that now we can look at memories being formed. there is still something missing though from the physical changes we can observe to the cognitive sensations we experience.


http://www.discover.com/current_issue/index.html


Name:  geoff
Username:  gpollitt@haverford.edu
Subject:  article
Date:  2003-03-17 12:26:55
Message Id:  5023
Comments:
when you get to the site, scroll down under "letters" and click on R&D to get the article.
Name:  marissa
Username:  mlitman@brynmawr.edu
Subject:  personality and reactions
Date:  2003-03-17 16:47:21
Message Id:  5032
Comments:
Well, I think that I have possibly written on this topic before, but Danielle's mention of personality, behavior, and the affects of our environment is very interesting. I thought her point that people are "pre-programmed with certain membrane permeabilities that translate into naturally chipper dispositions" was something that struck me as very likely. The idea that people may hinder their own behaviors and reactions in accordance to the way they have been "trained" to is very common. Maybe not as permanant as other behaviors that are considered to be more common or reflexive, but still similar. Whether or not that is innate, a chemical, or a physical change is really my question. We have discussed in other forums that certain mental illnesses may be chemical disruptions or actualy physical differnces in th brain or neuron patterns. If reactions are trained, but tanglible, what is the actual change that is taking place?
Name:  Neela Thirugnanam
Username:  nthirugn@brynmawr.edu
Subject:  
Date:  2003-03-17 21:31:09
Message Id:  5038
Comments:
The question of whether our current knowledge of permeabilites and action potentials is enough to understand the brain and behavior seems like one of those questions that begs for a negative response because of all of mysteries of the brain that go unanswered despite science's explaination (such as pre-cognition). I can understand how what we discussed explains personality and other such aspects of behaviors, but it is the spontaneous actions of the body that remains a bit unsettling. Action potentials, changes in permeability, and changes in ionic concentration which cannot be traced back to a source are like biologic I-functions. These independant actions should be the result of another layer of biologic coding, but if they are not, then perhaps there is a an aspect of behavior not dictated by the brain. All of my statements in this posting could easily be explained away if I knew more information on the source of seemingly independant actions of the brain. If the answer was discussed in class and I just didn't catch it, my repsonse to the question would be that I don't think we have enough information to explain behavior as a sole function of the brain.
Name:  Stephanie
Username:  srichard@brynmawr.edu
Subject:  Can the brain explain it all?
Date:  2003-03-17 22:36:44
Message Id:  5039
Comments:
Whether of not permeablities and action potentials can explain all of human behavior, I don't know. But I do know that it is exciting to see how much it can explain. I really liked seeing how our senses of sight, smell, and hearing can be connected to permeability.

I liked a phrase that Marissa used: "trained, but tangible", this is pretty much the key to using neurobio to explain behavior. The brain does not act on its only on its own, we see this through receptor potentials. I makes sense that things other than biology have an effect on our actions. What I really want to know about if how susceptible the brain is to modification.


Name:  alexandra
Username:  alippman@brynmawr.edu
Subject:  explaining personality change
Date:  2003-03-17 22:41:23
Message Id:  5040
Comments:
When thinking about how personality is controlled by brain, it is interesting to think about how personality changes. Would the dying of neurons explain how personality changes? Or would change be interpreted as new pathways between neurons that have some how arisen or started. In understanding how personality can be a product of the brain, it is important to still appreciate how experiences or choices (even though based on the brain's "decisions") can in turn create new neuronal pathways. These new pathways could influence behavior such as personality. For example, I'm sure my decision to go to Bryn Mawr must have affected my personality. I think I am more open-minded now than I was in highschool. Although this increased open-mindedness may be a product of the brain, the change in the brain would have stemmed from a change in environment.
Name:  Laurel
Username:  ljackson@brynmawr.edu
Subject:  
Date:  2003-03-17 23:04:07
Message Id:  5041
Comments:
My 8-year-old cousin was recently diagnosed with petit mal seizure disorder. Although her diagnosis came a few days ago, she's probably been suffering from seizures for years. Her parents (now having guilt issues) told me that they noticed she would "space out" for a few moments before "snapping out of it". Within the past few weeks, these episodes have come more frequently. I have been looking into the subject on the internet, and I came across this article which I find very interesting from a biological and anthropological point of view. The concept that the functioning of the brain can be altered by diet is one that I had not considered carefully. Does the disorder occur more often in cultures emphasizing low-fat diets?

http://www.nlm.nih.gov/medlineplus/news/fullstory_11930.html


Name:  Andy Greenberg
Username:  agreenbe@haverford.edu
Subject:  Back to the drawing board
Date:  2003-03-17 23:07:07
Message Id:  5042
Comments:
In last week's forum, I asked whether the idea of an independently functioning action potential might be able to explain free will in any way. I've decided since then that an independent action potential doesn't really help the resolution of the free will controversy. Although the independent action potential might seem self-controlled, it really is just as determined as any other part of the brain. An action potential that fires without stimuli is still determined by genetics and an infinite collection of other physical causes...The fact that it starts within the body doesn't indicate any sort of real agency. So, sadly, the problem of free will reappears as strong as ever.

Now that I'm back where I started, I guess I have to settle on the boring conclusion I'd come to in my web paper: free will is epiphenomenal.


Name:  vivian
Username:  vbishay@brynmawr.edu
Subject:  
Date:  2003-03-17 23:26:50
Message Id:  5044
Comments:
questions are being raised in the forum about how changes in the brain-physical, chemical, changes in our preprogrammed(?) membrane permeabilites- affect behavioral changes. i've been looking into dual diagnosis lately and it seems to be connected to the questions raised. dual diagnosis is the concurrance of mental illenss and substance abuse. one point that seems clear from articles i've read is that the etiology of these problems is really not known and questions of how the disorders affect one another and of whether shared biological vulnerability plays a role are pretty much unanswered. one line of research that i thought was really interesting suggests that physical changes inside the brain take place after developing either a mental illness or substance abuse problem, increasing vulnerability to the other- so if our membrane permeabilities are preprogrammed can they be reprogrammed and how do environmental factors like treatment and medication affect change in our programming?
Name:  Christine Kaminski
Username:  ckaminsk@brynmawr.edu
Subject:  
Date:  2003-03-18 00:00:23
Message Id:  5045
Comments:
In response to Dr. Grobstein's question, I don't think that necessarily changes in neuronal pathways can be completely accountable for behavior. I do think however that those changes can affect personality, as Alexandra suggests, yet not completely. I still believe though that environments have a strong impact on behavior-including upbringing, culture, and regional backgrounds. Can shifts in neuronal pathways be solely responsible? I don't think so. While signals sent and lost could account for changes in behavior, I do believe that it could very well be a whole combination of factors that have such an effect.
Name:  Nicole M.
Username:  nmegatul@brynmawr.edu
Subject:  
Date:  2003-03-18 00:17:56
Message Id:  5046
Comments:
In response to Prof. Grobstein's question about whether we can get all of behavior and human experience out of the properties of neurons and their ways of talking to one another, I agree with Alexandra when she said, "Although this increased open-mindedness may be a product of the brain, the change in the brain would have stemmed from a change in environment." I have been thinking about the extent which environment (experience socially and physically; exposure to certain climate, chemicals, or diets; type of culture; upbringing; traumatic events etc...) influences the properties of neurons and their ways of interacting, and if it has any influence at all. Is the manner in which each person deals with the environment set before them the result of pre-programmed neural properties or does environment alter these properties or do both components of environment and neural interaction rely upon each other? I wonder how the personality of one person who had been raised in one lifestyle would differ from the very same person raised in a drastically different environment. It is highly unlikely that the same human would develop the same personality traits and human experience, which would suggest that environment does influence neural functioning, if in fact behavior can be attributed to neural interactions. I guess one could say that environment can affect predisposed properties of neurons and their interactions which in turn, dictate all behavior and human experience, but I am not yet comfortable enough to make such an affirmative statement.
Name:  maria
Username:  mcruz@brynmawr.edu
Subject:  mental illness and substance abuse
Date:  2003-03-18 07:52:21
Message Id:  5052
Comments:
I was interested in Vivian's comments about the link between mental illness and substance abuse. The idea that changes in the brain caused by one of these 2 disorders could increase susceptibility to the other intruigued me. I confess that while I have always had sympathy for those people with substance abuse problems, I have never really considered them to be diseases. This talk of brain chemistry, etc. makes me wonder just how much control people with addictions have over their problems?
Name:  nicole
Username:  njackman@brynmawr.edu
Subject:  is it enough?
Date:  2003-03-18 09:55:56
Message Id:  5056
Comments:
In response to Professor Grobstein¡¯s question ¡°Is that enough?¡±. I that the brain can control behavior. If there are 4 nitrogenous bases that can create a tremendous amount of diversity in and across species, I think that action potentials (triggered and autonomous), permeability changes, and chemical intermediaries can somehow produce all of human experience.
Name:  Patty
Username:  ppalermo@brynmawr.edu
Subject:  
Date:  2003-03-18 18:10:39
Message Id:  5066
Comments:
I am curious to understand what we feel is being taken away from us in the acceptance of brain and behavior as one. I think, to answer Paul Grobstien's question, what is missing is our ability to include free will. Maybe, if free will does not fit within our summary of evidence,and if we have compiled this summary of evidence in a way that seems logical and rational to us,then we should not be afraid to entertain the idea that we have no free will. Abandoning the need to "include" free will may allow us to develop those things we understand as the brain and those things that we understand as behavior into one cohesive "box." Even in a science that seems to be the polar opposite of Neuroscience, (Behavioral Psychology,) they too have an extreamly hard time defending free will. Our own behaviors, even if they are displayed partially independant from the brain, we agree are contingent upon other things (i.e. phylogony, ontogony) and those place huge contrictions on our conception of free will. If we find more evidence to discard free will than we do to keep it, we should encourage ourselves to look at the possibilty that there may not be any such thing as free will.
Name:  Shanti
Username:  smikkili@brynmawr.edu
Subject:  
Date:  2003-03-19 19:26:03
Message Id:  5107
Comments:
I found what Nicole wrote to be very interesting. It is true that we find many facets of behavior are directly influenced by our environment, however, I would like to pose the idea that some behaviors and actions rise neither from conditioning nor environment, and that they in fact arise spontaneously. We are tryin to find where in our brain we can account for creativity or personality. Maybe those things arise independent of what we see and hear around us. I believe that as much as a person can be conditioned, we can resist conditioning as well. No person is merely a mixture of genes and environment. We know this because no two people are the same even if they live in the same town or come from the same family. Maybe this is because of independent thoughts that our brain is capable of generating. Or maybe we are just not sensative to those thoughts just as we are not sensitive to propioceptors. There are many things in the world that humans are not aware of because we do not have the proper sensors for them. I think that maybe creativity and personality could be two of those things. As we look at our neurons, we don't seem to be able to find the answers to those questions but maybe we would if we just looked at them a different way or learned to hone our senses so that we start perceiving the things that are not immediately obvious. I think its time that we take a fresher approach.
Name:  Clare
Username:  csmiga@brynmawr.edu
Subject:  
Date:  2003-03-22 13:28:21
Message Id:  5129
Comments:
In response to Shanti's comment, however, even people from the same family have a different genetic makeup and even identical twins that live together encounter different experiences. Therefore, can't these account for individual differences rather than spontaneous differences in personality? It's hard for me to imagine anything other than genes and environment accounting for personality or how behaviors and actions would arise spontaneously. Is this referring back to the idea of free will or a soul or are you suggesting something completely different? Also, it's true that an individuality's personality can form by resisting conditioning as much as by yeilding to it, however, isn't the former as much of a response to environmental conditions as the latter? Without some sort of environmental or biological stimulus to resist conditioning from, it seems like this part of an individual's personality could not form. I guess I have no problem believing that my individuality simply comes from my individual genetic makeup and experiences. I feel like these are special things that no one else can claim for themselves and even though it may seem like it leaves me with little control over my individuality, I believe that it does. Just because my biological instinct tells me to do one thing, I can learn from my own individual experience to do something else. Maybe I did not get to "choose" this previous experience, but I had it, and it is mine, and I am choosing to learn from it.




| Course Home Page | Course Forum | Brain and Behavior | Serendip Home |

Send us your comments at Serendip

© by Serendip 1994- - Last Modified: Saturday, 22-Mar-2003 15:46:21 EST