Biology 202
Neurobiology and Behavior
Spring 2002

Forum Archive - Week 4

We've gotten to neurons, the smallest boxes of the nervous system, and discovered that they all pretty much use basically the same "signal", an action potential. What does this (and the associated "see thunder and hear lightning" problem) do for our "brain=behavior" idea? What new problems do we have to contend with given what we know about action potentials?

Name:  biz
Subject:  brain as a super computer
Date:  2002-02-15 00:09:25
Message Id:  997
i liked learning that neurons send signals, and no matter what kind of message they relay, they're all the same signal. i.e.: movement of knee signal=blinking your eyeball's just the final destination of the signal that determines the subsequent action.

it got me thinking about the brain and different areas that make it up. signals are differentiated based on where they end up. one thing i don't understand is how any signal decides where it is going, or how to get there. is there a predisposed pathway from eye to brain that can never go anywhere else? is this pathway clearly marked, like a street with stopsigns and do not enter-one way traffic signs? or is this a path that is not interconnected with other pathways, therefor a signal isn't given the opportunity to possibly stray?

Name:  Nicole
Date:  2002-02-15 14:31:51
Message Id:  1000
Learning about the signals neurons send got me thinking about how all the signals are the same. For me, this concept is a little hard to grasp because of the actions those signals produce. Thinking about neurons and how they work got me thinking about people who have split-brain. The way these people act is an interesting phenomenon, which helps to support the neuron messages. These people can see something on their left eye and write it with their right hand. The right side of their body does not know what the left side of their body is doing.
Name:  Rebecca Roth
Subject:  Always interesting
Date:  2002-02-15 22:50:53
Message Id:  1002
Wondering people's thoughts on the cat clone.

"The cloned cat, called cc, for carbon copy, is a genetically identical copy of a 2-year-old female cat, Rainbow. But Rainbow and cc do not look alike, illustrating that identical twin cats may not have identical coats. " NY Times Feb 15th.

Name:   Paul Grobstein
Subject:  week 4
Date:  2002-02-16 10:41:56
Message Id:  1004
So ... you can, as always, write about anything you like (yes, the issue of cloning as per this week's news reports is relevant ... coat patterns different ... behavior also?). You have web papers due a week from Tuesday, maybe some sharing of what you've begun learning? And, there is always what we're talking about in class, so here's a question to get you started if you need/want one:

We've gotten to neurons, the smallest boxes of the nervous system, and discovered that they all pretty much use basically the same "signal", an action potential. What does this (and the associated "see thunder and hear lightning" problem) do for our "brain=behavior" idea? What new problems do we have to contend with given what we know about action potentials?

Name:  Beverly Weiss
Subject:  lightning/thunder
Date:  2002-02-17 19:54:49
Message Id:  1018
I am perplexed about Prof. Grobstein’s theoretical that one could “switch the cables” so that the auditory nerve delivers an output message of hearing thunder to the optical repository in the brain and the brain would translate “see” thunder; And conversely, the optic nerve could deliver an output message to the aural repository and the brain will “hear” lightning.

I understand that theoretically this makes sense, however, aren’t these cells very specialized? Can cells take over properties of other cells? When the brain is damaged, there are cells that take on the job of other cells, could this happen in neurons that are so specific as aural and optical cells? Even though the action potential is the same in every cell fire or no fire)the cells still all specialize. The brain still equals behavior, but what behavior?

Name:  Ricky
Subject:  thunder/lightning
Date:  2002-02-17 22:55:43
Message Id:  1021
The "see thunder and hear lightning" problem seems very interesting in supporting the idea that every neuron receives a "same" signal or action potential and only the outout response is different. However, I am somewhat confused in how the auditory nerve can send a message of hearing thunder to the optical part of the brain and the brain would translate "see" thunder and vice versa for a message sent by the optic nerve to the auditory part of the brain that would be translated into "hear" lightning. If the thunder/ligthning problem occurs, what in our brain is used to correct a message that is sent to the wrong part of the brain?
The neurons all seem to deal with an action potential, but where does the stinulus lie? Is the action potential caused by the stimulus from the organism's external or internal environment? For instance, what stimulus triggers a headache? How do various stimulus affect the action potential?
Name:  Aly
Subject:  Neurons
Date:  2002-02-18 00:34:47
Message Id:  1022
It is interesting that neurons are all the same and are only differentiated from each other by the specialized receptors in the brain. I understand how different behaviors can occur in a specific individual because inputs are just received differently, but I question what accounts for the differences in behavior demonstrated by different people? If the signals are all carried along the same pathways and use the same action potential method, then what accounts for so-called behaviors that make us individuals?. If brain does equal behavior, then the differences in the brain would have to be responsible for the differences in behavior. Are these differences too located in the specialized receptors of the brain?

The idea of seeing thunder and hearing lightning really facinates me. If the hearing part of the brain recieved signals from the eye, how exactly would it be interpreted? It is hard to fathom what thunder would look like. Would the traveling signals produce a picture of something familiar, or would the induced picture not make any sense at all to our brains? This experiment gets me thinking. If the receptors can be changed to induce physical differences in an individual, can receptors responsible for such things as emotion be changed too? If we somehow cross emotional paths or paths responsible for the thought process, could we then get an indivual to think and "act" like another person? If this be the case, then I see no reason why brain would not equal behavior. It would show that a material change could bring about a change in an immaterial thing. If it was not the case, then what is the difference between physical responses, like hearing and seeing, and emotional/thinking responses?

Name:  lilian
Username:  Anonymous
Subject:  thunderandlightening
Date:  2002-02-18 11:45:23
Message Id:  1027
It seems to me that the important part about the thunder=lightening example, that is, the point which the example illustrates, is that all of the signals in the brain are the same kind of signals, but they travel on different pathways to different destinations. Of course, if the pathways were rerouted, it follows that their signals would terminate in different locations. If you can understand the example in theory, that's all you need, because, of course, we can't ACTUALLY do this expirement on a living specimen. The question of what thunder would look like or what lightening would sound like, is an interesting question with no definate answer. We could think about the properties of light and sound. Length of sound waves (tone) could be compared to color (length of light waves), and intensity of sound (loudness) might correspond to intensity of color (brightness). I'm not sure if these correlations work- does anyone have any suggestions?
Name:  Cindy Zhan
Date:  2002-02-18 12:25:45
Message Id:  1028
i was very intrigued by the idea that the time that takes for the action potential to occur acccount for the "time" to think. I knew about "time to think" and action potentials, but i never made a connection between the two.Im excited to learn about other ways that action potential impact our behavior other then its impact on how long it takes for us to think.

Speaking of making connection. I'm doing my research on math and music and how the the brain connect those too. Im hoping to apply the information that i learned in class to the paper. Hopefully.. somewhere in the paper i shall write about how action potentials affects music and math or vice versa.

Name:  Hilary Hochman
Subject:  action potential
Date:  2002-02-18 13:48:53
Message Id:  1029
That the brain uses only one signal, and that this signal is itself an all-or nothing-proposition, seems to argue against the idea of infinite variability. [And how does the human brain engage in fuzzy logic using only on/off signals??] Simultaneously, however, this simple organizational principle gives the brain great flexibility -- the pathway of the signal determines how the information is used, and there is a virtually infinite number of arrangements for the pathways. A single change in the arrangement of neurons could result in numerous changes in behavior. But for behavior itself to change over time, then the neuronal pathways must change too, either by changing their arrangement and/or by changing the responses to input and/or changing their ability to receive a specific type of input. In such a sensitive mechanism, how does this change occur?
Name:  kelli deering
Subject:  perplexed...
Date:  2002-02-18 14:27:30
Message Id:  1032
The proposed experiment in which the aural and optic nerves are reversed to result in the ability to "hear" lightening and "see" thunder seems to be a clever thought, but somehow I feel it is not physiologically feasible. Yes, all neurons are structurally and functionally similar, relying on action potential as their energetic signal. However, the receptor proteins of cells are different and specialized to produce certain appropriate responses.

Different kinds of sensations are associated with different receptor cells. For example, the rod and cone receptor cells in the retina respond only to the electromagnetic radiation of light. Hair bundles that move in response to vibrations from sound waves top the aural neurons. If these specialized units are altered, then I do not feel that any useful response would result from stimulus. Could energy from light possibly be interpreted by aural neurons? Likewise, could thunder be "seen" considering the physiological limitations of optic neurons?

I agree with Hilary that great variability lies in the arrangement of neural pathways. This supports the idea that complex human behavior differs from, say, the behavior of a frog in brain organization. I feel that it is in this theory that the variation with respect to brain=behavior argument has its strongest foundation.

Name:  cass
Date:  2002-02-18 19:11:51
Message Id:  1039
Do we actually know what it means to see thunder and hear lightning?
I wonder if it even matters if the nerves were switched because in the end we would get the same message. If the nerves were switched then would we actually be able to tell the difference since we are getting both stimuli anyway? When thinking about this phenomenon, I remember that what creates different reactions and behaviors and essentially thinking, is the organization of neurons and the different pathways. So, the nerves are switched, but we still get a behavior, just a different one.

I guess what is more important is where these signals come from. Obviously, the thunder and lightning, being stimuli, would come from the action potential traveling down the length of the axon. After that, it then goes to the brain, and I guess elicits some sort of behavior depending on where it goes. But, the stimuli never changes, it is just how that person chooses (or not) to interpret it. If you think about all of the individuality in the world and that the organization of neurons is what differentiates those people and animals, then the seeing thunder, hearing lightning makes sense.

Name:  Rebecca Roth
Subject:  Week 4
Date:  2002-02-18 19:37:14
Message Id:  1040

The nervous system relies upon organization. There are interactions between groups of neurons. We need to know more about the nervous system in relation to behavior itself. We behave without being fully aware all of the time. Everyone has a brain, but everyone’s brain is different. Therefore, if we have different brains, to a certain extent, we will see and hear things differently. We would be using the same “signal”, but could it connect differently? Could the same processes that we are experiencing be looked at differently depending on how detailed we are? People see things differently. You can ask people what they just saw, and you could have thought you saw the same thing, but really didn’t according to the people you ask. People can see different aspects of different things. What about interpretation?

Name:  Joan Steiner
Subject:  Bodily electricity
Date:  2002-02-18 19:55:13
Message Id:  1044
The brain and nervous system is a marvelous specimen. All the signals circuiting throughout our bodies, no wonder the human form produces so much electricity.

What I find fascinating about psychology and psychiatry is that one of the ways they attempt to explain someone's strange behavior, or different behavior, is a misconnection between certain neurons or a connection not getting through. After learning about all the different possibilities within in the nervous system itself I find it amazing how anyone really has the gaul to say that someone's system is not properly connected.

With a system like the nervous system, how can anyone even begin to comprehend what could possibly be a "right connection"? And how we attempt to try and mess with all the numerous chemicals produced by the brain that transmit through all our neurons. Perhaps a question I am going to pitch is that with such a vast and complicated system, there is even an attempt at defining "normal".

Name:  Amy Cunningham
Date:  2002-02-18 20:09:14
Message Id:  1045
I don't think that the idea of all neurons having the same action potential changes the brain= behavior idea too much. As we said in class earlier this semester, our brains contain trillions of neurons that can be arranged in an almost infinite number of ways, so the fact that they all have the same signal doesn't matter as much as their arrangement. Also, as others in the forum pointed out, neurons pass their siganls along to different kinds of receptor cells, which also can account for variations in behavior.
Name:  Gabrielle
Subject:  intelligence
Date:  2002-02-18 20:55:23
Message Id:  1050
Since we were talking about the speed of action potentials I started thinking about intelligence. Action potentials can't be the determining factor in how fast someone figures out a problem because some people can do problems a lot faster than others. That can possibly be explained by thinking about the connections between the neurons. In a more intelligent person the connections must be more efficient. The signal doesn't have to travel through as many neurons. Instead of going from A to B to C, the signal goes directly from A to C. Then, there should be some limit to how fast something can be thought of or done. But, I feel like in this day and age everyone is doing everything faster and no plateau is being reached. Maybe there is an infinite possible efficiency.
Name:  Tara Monika Rajan
Subject:  hearing lightening and seeing thunder
Date:  2002-02-18 21:33:53
Message Id:  1052
It seems impossible to understand the concept of seeing thunder and hearing lightening since we’ve all experienced it in the opposite way. How could lightening make a sound if it is just very high energy travelling at a certain wavelength? And since we’ve understood thunder to be energy which is released in the form of sound, how would it look to us? I think that the idea of hearing lightening and seeing thunder would not necessarily mean that lightening would become a sound and thunder would be a sight, but maybe instead our eyes would do the same thing that our ears do—therefore we would still hear thunder, but we would hear it with our ears rather than our ears. If this were the case, then our eyes would act as our audio pathway to the brain and our ears would be the visual way to the brain. This is a very interesting concept, but is there anyway to actually know for sure what the results of the exchange would be?
Name:  natasha
Date:  2002-02-18 22:11:18
Message Id:  1053
I have to admit that knowing that all the neurons in the body respond through action potential(the same mechanism for all), troubles me. To me this implies a certain "limit" to the nervous system. But since we know that everyone is different, accounting for the fact that there are many different nervous systems, then where does this difference come from? Are there mechanisms in our body that regulate the input/output system of the neuron? Just like some people in this class believe, I believe that if we can postulate that different nervous systems account for different individuals, then it would be fair to say that when one "changes" or "modifies" their behavior, that intails a change in the nervous system. But what kind of change is that?
Name:  Michelle Tahmoush
Subject:  Prozac
Date:  2002-02-18 22:42:00
Message Id:  1056
I think that we have pretty much exhausted the hear lightening/ see thunder perplexity and found that we don't have any definite answers. So, I am just going to throw in a comment about my paper topic and see if it rubs anyone the wrong way.

We have found in America's society that there are many people who suffer from depression. Some people have found comfort in taking antidepressant drugs claiming that they're a new person on this medication. What exactly is this attributed to -- the medication or the person's thinking that the medication should change her mood? This may seem trivial to some people, but just consider the millions of dollars spent on antidepressants a year. Are people just being exploited or do these medications actually work? I have found some interesting facts that could lead one to believe that people are wasting their money. For example, Prozac did not prove to be more effective than the placebo in the initial trials. The data had to be manipulated in order for the Food and Drug Administration to pass it as legal. There are other such claims that only some antidepressants are effective for certain people and that the psychiatrists who prescribe the medication don't know what is suitable. They simply try different medications that have the less lethal number of side effects until maybe one works. The whole world of psychiatry seams very shady to me.

Name:  Shannon Lee
Subject:  connectivity
Date:  2002-02-18 22:55:07
Message Id:  1057
I am still having trouble comprehending the idea of seeing thunder and hearing lightning, but I believe the possibility is becoming clearer. All the action potentials are the same between the neurons, therefore, connectivity between cells and receptors must allow for the many functions of the brain. The potentials are all or none so how many potentials and the rate of potentials between different neurons must be important. The “see thunder, hear lightening” idea supports the idea of brain = behavior, suggesting that if the neurons are connected differently the brain will behave differently. Certain cells develop specialized specialties in the brain, depending on the region, and then branch out to make the correct connectivity. It seems the neurons responsible for the picture formed in the brain would be so highly specialized and need such specific amounts of action potentials and neurotransmitters that they would not understand the information coming from the auditory sensory axons.
Name:  sook chan
Date:  2002-02-18 23:25:15
Message Id:  1060
Does thunder look like anything and does lighting sound like something? It does, if we believe it does, or maybe past experiencs have made us believe and recognize a certain thing. It makes sense that signals are all alike and that the transmission and processing of those signals undergo similar pathways, however, where in this pathway does our brain come along?
If transmission of signal is equated with the box within boxes summary, then what part does the I function play?

I am writing my webpaper on dissociative identity disorder, focusing less on the mystery of the disorder than the mystery of how someone can make themselves believe that something is real if they just try hard enough.

Name:  Michele Drejka
Date:  2002-02-18 23:52:43
Message Id:  1062
a quick thought on the cloned kitten-- when i read about it in the papers, one of the reasons for the cloning of pets specifically was to be able to reproduce the beloved pet that the owner has lost and misses so much. although it sounds like good intent, i doubt the cloning of a pet could ever really result in replicating the behavior and personality of the original animal unless its individual eccentricities were caused by a genetic factor, the behaviors of the animal are most likely molded by the un-reproduceable experiences it has in its youth and throughout its life. i won't beat a dead horse by going thru the entire nature-vs-nurture debate over again, but i think its ridiculous that a major push for cloning at all in the news these days is to promise a replica of a loved one.

the see thunder/hear lightning concept confuses me a little still. does an audio input have the ability, in a case like this, to generate an image that the brain believes it is seeing? is there any way an audio input can actually cause the brain to perceive an image that is not there? the light and sound waves are information that is taken in only by specific non-interchangeable physical methods. how would the message be translated from one to the other?

getting off the topic--- I like Michelle's concept for her paper, i think the psychosomatic effects of taking a pill and expecting a specific effect are very interesting. ive read about various psychological studies here and there in which the results showed that the psychosomatic effects were actually more effective in behavior than the actual physical effects of the drug-- (alcohol comes to mind immediately, with people always loosening up significantly upon their very first sip). it would be interesting to learn about the strength of the placebo effect with anti-depressants.

Name:  Serendip Student
Subject:  procrastination
Date:  2002-02-19 00:12:39
Message Id:  1064
Everyone can relate to it, and this week I have fallen victim to it several times - procrastination. Noticing a definite frequency in my procrastinating habits, I have decided to research it for the web paper. Ironically, despite the evolving brain=behavior debate, my inquiries into procrastination were excited by my curiosity of my annoying behavior. I caught myself addressing it as such, prior to reading material on the subject and realizing it is clearly linked to the brain. Newsflash, brain=behavior! This stood as further proof that while I comprehend the linkage of behavior to the brain, I have not fully accepted it. Perhaps I will be further convinced of the truth with my research for the paper.
Name:  Mary Schlimme
Username:  Anonymous
Subject:  Cloning
Date:  2002-02-19 00:45:28
Message Id:  1065
I didn’t read the article on the cloning of the cats, but I tend to agree with some of the comments posted here already that stated that while one may clone the cat, you are not necessarily cloning his behavior and personality. Many experiences in life make us who we are, and I think that it is the same for our pets. Just because a clone has the same DNA doesn’t mean that he will behave in the same way since his experiences must be different from the first cat’s experiences in some significant ways and our experiences help define who we are. I think that if this type of cloning is allowed to occur in the general population then we might have a lot of upset people wondering why their cloned animal doesn’t behave the same way that their first animal behaved.

In regards to the lightning/thunder issue, I too am a bit confused on the whole hearing lightning and seeing thunder idea, and while I understand it in theory it is hard to grasp in a more concrete way. Hopefully this will become clearer as the week goes on.

Name:  alisa
Date:  2002-02-19 01:28:09
Message Id:  1067
I have more questions than comments. If there are mistakes made in the brain wiht how things are received or interpreted, what in the brain makes the corrections? How does the brain translate the signals received and where does this translation take place? I still wonder how the same imputs can be received differently for different people.
Name:  Gavin Imperato
Subject:  Lightning, Thunder, Cloning
Date:  2002-02-19 02:37:48
Message Id:  1069
This whole idea of seeing thunder and hearing lighting seems to fit very well with the "brain = behavior" idea. The idea that simply swaping a cable connection can lead to such a simple and uncomplicated result troubles me, however. Didn’t we disucuss in an earlier class that often complicated things can result from relatively simple processes? How can we be totally sure that all that is at stake here is a pathway and an endpoint, with the two as interchangeable parts?

About the cloning issue – I agree with Mary’s post in which she, citing the importance of experience in the development of personality, talks about how identical DNA might not necessarily make for identical behavior in humans. It seems to me that we might finally be able to put the brain = behavior and nature vs. nuture debates to rest when humans are cloned and we start doing some controlled experiments to determine the effect of environment on behavior.

Name:  peffin
Date:  2002-02-19 08:54:45
Message Id:  1072
I think that Gabby brought up an interesting example supporting brain = behavior.

"Instead of going from A to B to C, the signal goes directly from A to C."

Action potential can be used as a measure of how fast one thinks. Yet not everyone thinks at the same speed. So she suggested that there are "short-cuts" in the nervous system.
This causes me to wonder, how are these new paths formed? How long does it take someone to repeat an action (physically or mentally) for the brain to recognize a short-cut?

Name:  Kathryn
Subject:  Michelle Tahmoush's Paper Topic
Date:  2002-02-19 09:44:13
Message Id:  1073
Michelle's paper topic really got me thinking about whether medications like Prozac actually work. I agree that psychiatry is not as exact in prescribing medications as other fields of medicine, but I think that this is due to the fact that there aren't any precise tests or diagnostic tools that would allow the psychiatrist to diagnose a patient with certainty. What I mean by this is that a psychiatrist can't just take a throat culture or a blood sample and send it to the lab to find out if the patient suffers from depression. Since there isn't a precise way to this, I think this is why the psychiatrist must experiment with medications -- they don't seem to have any other choice. Everyone's brain has the same chemicals, but they may have different amounts and different medications would effect their brains in different ways. That is why Prozac works for some people and not others. Of course I think that some people who take Prozac are experiencing the placebo effect. These people probably want the medicine to work so they believe that it does. However I think that these people are the minority. I think that medicines really can and do affect a person's mood and how they feel about themselves. One example that some people can relate to and that proves that chemicals affect the brain is how alcohol or drugs affects the brain. When someone is drunk, they feel and act very differently than they normally do. The same idea applies to drugs such as cocaine. While cocaine is illegal now and it is not considered to have medicinal purposes, at point it was used for medicinal purposes. Sigmund Freud prescribed it to many of his patients and he considered it to be a wonder drug. Of course we know more about it's damaging effects now and know that it is not a very effective medicine. However if chemicals like these affect the brain and how the person feels, then it makes sense that a drug like Prozac would do the same for some people. However it doesn't work the same for everyone which is why the psychiatrist must experiment with different antidepressants. Yet I think it is possible to find a drug that affects the brain in a way that helps the person feel better. However this needs to be a choice between the doctor and the patient based only on how the medicine makes the patient feel. What I object to is the drug companies advertising these medications on TV. This makes people think that a certain medication will solve all their problems and this might not be true. People respond differently to different treatments and the psychiatrist probably has more knowledge about these options than the patient. This is why I don't think it is a good idea for the patient to walk in and request a medication because it could increase the placebo effect, and make it seem as if the drug has no medicinal value since so many people would be on the wrong medication.
Name:  Sarah Eberhardt
Subject:  Cloned kitten
Date:  2002-02-19 17:16:29
Message Id:  1078
The experiment of cloning a kitten, and its results, provide strong evidence that the characteristics of an individual (i.e. behavior), are much more strongly influenced by its environment than by its inherent genetic layout. The example of fur patterns cited in class is just the start of this. If this cat has a frightening experience with a dog, it will likely be wary of dogs throughout its life, even if the animal from which it was cloned was quite friendly to dogs; if fed on canned food, the clone may (if it has enough intelligence), learn to respond to the sound of a can opener, even if the original animal ate dry food and therefore reacted to the sound of kibble falling into a dish. These things are examples of learning, pathways in the brain connecting in different ways because of the different experiences of the two genetically identical cats.

But how different can these animals become? Many domestic animals are bred to be relaxed around people and other animals; if a “friendly gene” is shared by the cats, then does this mean that biologically, both must retain a certain amount of amiability towards their fellow creatures, no matter how traumatizing their experience? What about intelligence? The two may each hear the sounds of their personal dinners, but are they both limited by the same IQ, perhaps to the point of being unable to connect the noises to impending dinner?

The “least wrong” answer I have come up with so far is this: the cloned cats are given the same framework, the same physical capabilities, within which to work. To put it more simply, each has access to the same number of puzzle pieces. How they put them together, and how successful the end result is, relies nearly entirely upon the cats’ personal experiences.

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