Chapter 6, page 100- When they say focus on mechanism,but it cannot be considered part of evolution, I am not sure what that means. The nervous system is a product of evolution, so how are the mechanisms so different? Chapter 6, page 102, for a resting neuron, the active ion channels are closed, but the passive are open. There was a good explanation of why K+ is more permeable to other ions, but I guess I am still a little confused on how this works. Chapter 6, page 106, As mentioned on page 100, there are three different kinds of neurons. On page 106, they describe the two different kinds of synapse. does it matter what kind of neuron goes to which synapse?
Q1: Basically it's because mechanism is a proximate question. We're going to start off looking at things at the level of the individual and how the nervous system makes it more likely that particular responses occur--and for stimuli to be perceived--rather than looking at how these systems evolve (although we'll get to that when we look at ultimate questions!). Q2: We'll go over APs more tomorrow. If it's still confusing, let me know after I talk about them.
1) Chapter 6, page 101: I was wondering, if the wind-sensitive hairs on cockroaches allows them to escape from predators in such a successful manner (being able to escape about 90, 150, or 180 degrees away from the threat due to gusts of wind), then why don't other animals also have this mechanism? It seems that most mammals would just run away from the source of the threat, without this specific escape pathway. 2) Chapter 6, page 104: I was just curious as to why the sodium channels cannot be reopened right away after an action potential? I have heard this many times before, but can not recall a specific reason why this is the case? 3) Chapter 6, page 106-107: On the topic of how neuromodulators cause voltage changes that occur over a slower time course than those caused by "traditional" neurotransmitters, I was wondering if there was a benefit to voltage changes occurring at a slower rate?
Q1: That's how the cockroaches perceive the threat. You're right, it may not be the most advantageous in all animals (think how close a predator might have to be for this to work in something bigger than a cockroach!) and that's why we see other strategies. Q2: They can't be reopened right away because there's something called the channel-inactivating segment that moves into the channel and keeps it from opening again. The channel is inactive and can't be reopened for as long as the membrane is depolarized. It works this way because this is how action potentials stay unidirectional (so the message travels instead of coming back, does that make sense?). Q3: We'll talk about this more when we talk about hormones.
Ch6: P100: 1) Does the size of the creature play into the response and reaction time? Or is the speed of neurons firing across CNS and PNS not vary greatly in different sized bodies? Ch6: P 105: 2) When is an Electrical synapse used over chemical synapse? Meaning, what kinds of stimuli trigger electrical synapse of chemical synapse specifically? Ch6: P 107: 3) Page 107 describes how sound travels. How distorted do sound waves become when you only hear an echo? Are waves and direction askew because of it? Does it become unreliable judgement when birds only try t navigate off of echoing sound?
Chp 6, page 100- I don't understand how mechanisms are not a part of evolution. They allow the evolutionary change to occur, so wouldnt they have evolved to do this? Or did they always have the ability and it is the ability itself that evolved and the mechanism just helps? Chp6, page 104- Are both chemical and electrical synapses triggered by action potentials or is it just chemical? Chp 6, page 106- the book talked about voltage changing, obviously there has to be a specific level maintained to support life. is there a point that the voltage change occurs to slowly and firing doesn't occur? It's probably not important, but I love "what ifs".
Chapter 6, page 100: I'm a little confused about the cockroach example. It says that it has hairlike receptors that are sensitive to wind, and when they feel wind it transmits to the cockroach running away. If that's the case, is there a habituation point with the wind? Wind movement from predators and just wind in general are pretty similar, so wouldn't they just run constantly and waste energy?
Chapter 6, page 104: In talking about neural pathways, the saying goes "use it or lose it" is this the same for animals? Would they have pathways that they end up not using?
Chapter 6, Page 111: For the Barn Owl example, it talks about how it mainly uses sound to detect prey. It said that it's eyes are fixed into its sockets, which makes sense why they are so keen on using hearting to get food, but I was curious as to why their eyes are fixed into the socket. I feel like they would be even better hunters if they weren't,so was this trait always present in the owl or was it inherited over generations? How could the fixed eyes be an advantage or disadvantage?
Chapter 6, page 100: It says that at the base of each of the wind sensitive hairs on the cetrcus is a single sensory neuron that relays important information from the environment to the nervous system, if multiple neurons fire at once would the cockroach respond to the strongest single before it pays attention to the weaker neuron single?
chapter 6, page 104, i was wondering if more complex behaviors such as courtship behaviors will have a higher amount of synaps's to a neuron than a more basic behavior such as foraging behaviors would have?
chapter 6, page 105: if Electrical synapses cause behaviors such as the flight response of an animal due to the presence of a predator then what specific behaviors would a chemical synapse cause in an animal?
chapter 6, pahge 111: it states that hunting owls are able to locate and capture their prey in complete darkness, then goes on to tell how in an experiment a hunting owl was able to capture a skittering leaf across a ground, how can it tell the difference between the noises of a skittering leaf or leafs and a mouse in the wild, in other words is it harder for hunting owls in the wild to detect the location of their prey when there is a lot of changing environmental conditions such as strong winds?
Chapter 6, page 103: The textbook states that when the membrane becomes slightly polarized, some Na+ channels open. If the depolarization is great enough, voltage sensitive sodium channels open, and Na+ rushes in. Is there a different result depending on how quickly the Na+ enters the cell? Chapter 6, page 105: The book states that electrical synapses are less common than chemical ones. Why is that? I would think that a quick response would be favored over one that takes longer. Chapter 6, page 116: I don't think I'm clear on long-term depression. It occurs after a slow train of stimuli, opposite of LTP. Is this saying it is used so infrequently that it becomes weak?
Chapter 6, page 104: I am curious about ions and action potentials. I know that action potentials are triggered by the influx of ion, but im curious that if action potentials will still fully occur if there is still an influx of ions but it is just a small amount. Chapter 6, page 117; not fully related to neurogenesis in general but i'm curious about certain parts of the brain in animals. Can animals experience aphasia? Can neurogenesis be partial? Can there be a partial forming of neurons? Would there be partial signs of the behavior related to the neurons? Chapter 6, page 122: Can muscles still interact and function properly if there is a mutation or problem with the neurons? I know that neurons relay the movement of muscles but are there other ways around it?
Chapter 6, page 100- When they say focus on mechanism,but it cannot be considered part of evolution, I am not sure what that means. The nervous system is a product of evolution, so how are the mechanisms so different?
ReplyDeleteChapter 6, page 102, for a resting neuron, the active ion channels are closed, but the passive are open. There was a good explanation of why K+ is more permeable to other ions, but I guess I am still a little confused on how this works.
Chapter 6, page 106, As mentioned on page 100, there are three different kinds of neurons. On page 106, they describe the two different kinds of synapse. does it matter what kind of neuron goes to which synapse?
Q1: Basically it's because mechanism is a proximate question. We're going to start off looking at things at the level of the individual and how the nervous system makes it more likely that particular responses occur--and for stimuli to be perceived--rather than looking at how these systems evolve (although we'll get to that when we look at ultimate questions!).
DeleteQ2: We'll go over APs more tomorrow. If it's still confusing, let me know after I talk about them.
1) Chapter 6, page 101: I was wondering, if the wind-sensitive hairs on cockroaches allows them to escape from predators in such a successful manner (being able to escape about 90, 150, or 180 degrees away from the threat due to gusts of wind), then why don't other animals also have this mechanism? It seems that most mammals would just run away from the source of the threat, without this specific escape pathway.
ReplyDelete2) Chapter 6, page 104: I was just curious as to why the sodium channels cannot be reopened right away after an action potential? I have heard this many times before, but can not recall a specific reason why this is the case?
3) Chapter 6, page 106-107: On the topic of how neuromodulators cause voltage changes that occur over a slower time course than those caused by "traditional" neurotransmitters, I was wondering if there was a benefit to voltage changes occurring at a slower rate?
Q1: That's how the cockroaches perceive the threat. You're right, it may not be the most advantageous in all animals (think how close a predator might have to be for this to work in something bigger than a cockroach!) and that's why we see other strategies.
DeleteQ2: They can't be reopened right away because there's something called the channel-inactivating segment that moves into the channel and keeps it from opening again. The channel is inactive and can't be reopened for as long as the membrane is depolarized. It works this way because this is how action potentials stay unidirectional (so the message travels instead of coming back, does that make sense?).
Q3: We'll talk about this more when we talk about hormones.
Ch6: P100: 1) Does the size of the creature play into the response and reaction time? Or is the speed of neurons firing across CNS and PNS not vary greatly in different sized bodies?
ReplyDeleteCh6: P 105: 2) When is an Electrical synapse used over chemical synapse? Meaning, what kinds of stimuli trigger electrical synapse of chemical synapse specifically?
Ch6: P 107: 3) Page 107 describes how sound travels. How distorted do sound waves become when you only hear an echo? Are waves and direction askew because of it? Does it become unreliable judgement when birds only try t navigate off of echoing sound?
Chp 6, page 100- I don't understand how mechanisms are not a part of evolution. They allow the evolutionary change to occur, so wouldnt they have evolved to do this? Or did they always have the ability and it is the ability itself that evolved and the mechanism just helps?
ReplyDeleteChp6, page 104- Are both chemical and electrical synapses triggered by action potentials or is it just chemical?
Chp 6, page 106- the book talked about voltage changing, obviously there has to be a specific level maintained to support life. is there a point that the voltage change occurs to slowly and firing doesn't occur? It's probably not important, but I love "what ifs".
Chapter 6, page 100: I'm a little confused about the cockroach example. It says that it has hairlike receptors that are sensitive to wind, and when they feel wind it transmits to the cockroach running away. If that's the case, is there a habituation point with the wind? Wind movement from predators and just wind in general are pretty similar, so wouldn't they just run constantly and waste energy?
ReplyDeleteChapter 6, page 104: In talking about neural pathways, the saying goes "use it or lose it" is this the same for animals? Would they have pathways that they end up not using?
Chapter 6, Page 111: For the Barn Owl example, it talks about how it mainly uses sound to detect prey. It said that it's eyes are fixed into its sockets, which makes sense why they are so keen on using hearting to get food, but I was curious as to why their eyes are fixed into the socket. I feel like they would be even better hunters if they weren't,so was this trait always present in the owl or was it inherited over generations? How could the fixed eyes be an advantage or disadvantage?
Chapter 6, page 100: It says that at the base of each of the wind sensitive hairs on the cetrcus is a single sensory neuron that relays important information from the environment to the nervous system, if multiple neurons fire at once would the cockroach respond to the strongest single before it pays attention to the weaker neuron single?
ReplyDeletechapter 6, page 104, i was wondering if more complex behaviors such as courtship behaviors will have a higher amount of synaps's to a neuron than a more basic behavior such as foraging behaviors would have?
chapter 6, page 105: if Electrical synapses cause behaviors such as the flight response of an animal due to the presence of a predator then what specific behaviors would a chemical synapse cause in an animal?
chapter 6, pahge 111: it states that hunting owls are able to locate and capture their prey in complete darkness, then goes on to tell how in an experiment a hunting owl was able to capture a skittering leaf across a ground, how can it tell the difference between the noises of a skittering leaf or leafs and a mouse in the wild, in other words is it harder for hunting owls in the wild to detect the location of their prey when there is a lot of changing environmental conditions such as strong winds?
Chapter 6, page 103: The textbook states that when the membrane becomes slightly polarized, some Na+ channels open. If the depolarization is great enough, voltage sensitive sodium channels open, and Na+ rushes in. Is there a different result depending on how quickly the Na+ enters the cell?
ReplyDeleteChapter 6, page 105: The book states that electrical synapses are less common than chemical ones. Why is that? I would think that a quick response would be favored over one that takes longer.
Chapter 6, page 116: I don't think I'm clear on long-term depression. It occurs after a slow train of stimuli, opposite of LTP. Is this saying it is used so infrequently that it becomes weak?
Chapter 6, page 104: I am curious about ions and action potentials. I know that action potentials are triggered by the influx of ion, but im curious that if action potentials will still fully occur if there is still an influx of ions but it is just a small amount.
ReplyDeleteChapter 6, page 117; not fully related to neurogenesis in general but i'm curious about certain parts of the brain in animals. Can animals experience aphasia? Can neurogenesis be partial? Can there be a partial forming of neurons? Would there be partial signs of the behavior related to the neurons?
Chapter 6, page 122: Can muscles still interact and function properly if there is a mutation or problem with the neurons? I know that neurons relay the movement of muscles but are there other ways around it?