Departing the Vacuousness
Started by Uman2, September 25, 2018, 08:14:55 PM
Quote from: xSilverPhinx on September 28, 2018, 05:51:24 PMYou got me there, I have no idea. I'm guessing that it's not the case that there's absolutely no contamination.
QuoteHowever, when compared to the pharmacological approach, in which you basically inject a drug into the desired area of the brain, it will act on many, many cells in that region, even ones that wouldn't have been recruited anyway. Even so, you can still see behavioural effects that indicate more or less what is likely happening. Problem is there are compensatory netowrks that also come into play, but I won't ramble on about that...
QuoteSo, in comparison, optogenetics and even chemogenetics (DREADDs - you might like that name ) are far "cleaner" than the pharmacological approach.Pharmacology is what I have to work with, but I dream of an opportunity to possibly spend some time in a lab with money to spare and has the whole optogenetic toolkit at their disposal.
QuoteYes, there are loads of physiological differences between neurons that are activated, and at different time points too. For instance, the Early Immediate Genes I mentioned earlier result in proteins that are expressed by only the neurons that were recruited. We can see those too, using immunohistology techniques. One such gene is FOS, which encodes for the c-fos protein. This is a section of a rat hippocampus (proportionally larger than ours). The red/orangy cells are ones which were last recruited during a behavioural task, which express the early immediate gene protein, c-fos. The green dots are neurons and blue dots are the nuclei of neurons and glial cells. I could stare at that image all day.
Quote Funnily enough, that was the debate/argument that Golgi and Ramón y Cajal ("father of neuroscience") had at the turn of the 20th century. Golgi believed that everything was continuous while Cajal said that cells were discrete units, not continuously joined. Cajal was right, but both were awarded the Nobel prize. https://en.wikipedia.org/wiki/Reticular_theory Ah, I had to list the distinction between two types of synapse in the entry exam for my master's...let's see if I can still remember:There are two types of synapses, electrical, which are in physical contact with eachother and there are no neurotransmitters, and chemical, in which there is a cleft between them and neurotransmitters are necessary to get the signal across. In invertebrates, synapses are mostly electrical whereas in vertebrates they're mostly chemical. Electrical synapses are bidirectional whereas chemical synapses go only in one direction, from the presynaptic neuron to the postsynaptic neuron, though there are the so-called 'atypical neurotransmitters', such as endocannabinoids that go in the inverse direction (yes, our systems produce cannabinoids ). What else... Electrical synapses are faster than chemical ones. But if they're faster, then why have chemical synapses in the first place, and why do 'more evolved' animals such as vertebrates have more chemical synapses? One answer is that chemical synapses are regulated. They're more complex, but there are more 'steps' along the way that can be inhibited, facilitated or modulated, resulting in a larger behavioural repertoire.
QuoteAs for the ratties, yes, they are heroic. One of my labmates even added them in the acknowledgement part of his thesis. I thought that was awesome.
QuoteWhile animal experimentation is a controversial topic (my family, for instance, does not approve), all experiments have to be approved by an ethics committee made up of people from many backgrounds before they can be done. You have to be rigorous in your justification for using animals before you can use them. That's why scientists have to be 'salespeople' as well, you have to 'sell' your idea to others all the time.
QuoteMemories tend to become more generalised when they become more dependent on cortical structures. They lose detail, and become more 'semantic'. This means that they do lose some precision, and some researchers have proposed it is a form of forgetting, but I think not. Generalisation is not the same as forgetting. Implanting memories? I don't think it's theoretically possible to 100% transfer a memory because everyone's brain in different in their connections, memories are coloured by perception as well, and attention...I don't know. I'll have to look into that. It would be cool if it were possible, though!
Quote from: Ecurb Noselrub on July 25, 2013, 08:18:52 PMIn Asmo's grey lump, wrath and dark clouds gather force.Luxembourg trembles.