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14

I'd like to know what is the reference for amoebic learning. I cannot comment directly on this, but there is some evidence for "adaptive anticipation" in both prokaryotes and single-celled Eukaryotes which do not have a nervous system. In the case of E. coli, it has been shown that the bacteria can anticipate the environment it is about to enter. E. coli ...


7

In addition to the excellent response up top (by Poshpaws), one can also imagine how these systems work by looking at recent synthetic examples of single-celled organism memory. It is possible to design various bistable switches using protein pathways, RNAi, or other means that will latch a particular state. In that way, an organism could effectively ...


5

Short answer Temperature differences of 0.02 degrees Celcius can be distinguished, dependent on various factors including experimental conditions and bodily location. Background The ability to discriminate temperature differences depends on whether it is a cooling or heating pulse, the skin temperature, the duration of the temperature stimulus, age, bodily ...


4

An antagonist is a substance that blocks a particular pathway (a receptor). You can therefore test whether a particular drug acts through the opioid system by using an opioid antagonist. If your substance still works despite the presence of the antagonist (which should block the opoiod receptors), you can conclude that it is not working thorough the opioid ...


4

This isn't a case of gene splicing causing different protein variants. In the studies that identified these two functions (GHB sensitivity and riboflavin transport), they were using DNA derived from mRNA (cDNA), which means what was being expressed in their experiments did not have introns, so there was no chance for alternative splicing. This gene has a ...


4

As far as I know there are 5 receptors for far-red and red light which are the phytochroms(phyA-phyE) Its all about the ratio between red and far-red light. Each phytochrom has an inactive(PR) and an active(PFr) conformation. phyA is the only phytochrom which is activated by far-red light, so its active state is PR. (Only if the ratio between red and ...


4

Short answer No, orally taken painkillers act systemically. Background Taking a painkiller orally results in the drug being taken up into the bloodstream by the digestive system. From there it can potentially reach all tissues. In other words, a pain response does not act as a chaperone. A hypothetical drug that would home in on tissues with a pain ...


3

Short answer Slowly adapting mechanoreceptors in the skin mediate the perception of static pressure stimuli, while rapidly adapting skin receptors mediate swiftly changing (e.g., vibratory) stimuli. Background There are various skin receptors. Hairy skin, such as that encountered on the arm, contains at least four specialized mechanoreceptors, namely ...


3

What many drugs and compounds do is bind to cell receptors. These receptors then change shape and various things may happen in the cell as a result (including relaying a message to other cells). Something that binds to a receptor and causes activity is called an agonist. Something that binds to a receptor and causes a partial response is called a partial ...


2

Yes, it does cause lesions in rats, although I don't think it's been observed to do so in humans. See: http://www.druglib.com/druginfo/namenda/description_pharmacology/


2

A mechanical stimulus can act on a tissue with elastic and viscoelastic properties in two ways [1, 2]: distort the cellular membrane which leads to opening of ion channels. create tension on the extracellular matrix or cytoskeleton, to which a ion channel is bound, thus leading to opening of the channel. Stretch-activated ion channels opening leads to ...


2

Most NSAIDs derive their analgesic effects from inhibit the cyclooxygenase (COX) enzymes that produce the prostaglandin-H2 precursor to the prostaglandins that sensitize neurons to pain. Edit: With respect to where this takes place, the COX enzymes are expressed in inflamed tissues as well as constitutively in the stomach and kidney. The prostaglandins ...


1

This review 22 proteins in the NOD like human repetoire. It was published in 2013... The families are broken down into 9 general groups according to their domain composition in Figure 1 from that review. Most of them are not named "NOD".


1

Gi and Gs have a structurally different sub unit in their alpha chain. The receptors for PGE1 and adenosine interact with inhibitory Gi, which contains the same β and γ subunits as stimulatory Gs but a different α subunit (Giα). In response to binding of an inhibitory ligand to its receptor, the associated Gi protein releases its bound GDP and ...


1

This is more of a hypothesis I am not sure if suffocation per se would cause pain. Asphyxia, as RoryM indicated in their comments, can lead to anxiety and panic but not really pain. However, forceful breathing may lead to muscular fatigue which may result in pain. Pain induced by muscle fatigue is called myalgia. Myalgia is possibly triggered by low pH ...


1

Being no expert on pain, I will share some thoughts on the issue. According to the following site(http://www.helpforpain.com/arch2000dec.htm), there are two types of pain: nociceptive and neuropathic pain. Neuropathic pain involves the central and peripheral nervous system, a possibility I would discount due to no apparent link to suffocation. Thus, it is ...


1

I think it's best to break this question up in to two parts: What mutations account for red hair and fair skin in humans How might these same mutations affect pain sensation MC1R variants & red hair The MC1R gene encodes a transmembrane receptor protein (belonging to a very common family of receptors), called melanocortin 1 receptor. It also has ...


1

In protein phosphorylation, the phosphate group transferred from the kinase to the substrate comes almost universally from ATP. However, there is evidence of some protein kinases using GTP as their phosphate source, although they are few and far between.


1

Its fairly common for a gene to have multiple names. I cant say for certain, but Jax and GeneCards also lists them as being synonymous so I would say its safe to say they are the same http://www.informatics.jax.org/marker/MGI:1289288 http://www.genecards.org/cgi-bin/carddisp.pl?gene=SLC52A2 Edit in reply to comment: In higher level Eukaryotes the vast ...


1

I think a lot of your questions try to split the hair; is this happening at the chemical or the histological level and I do get what you're asking, but you should know that the distinction is often not worth making. Pretty much whenever a neuron's involved, the interesting biology is multi-scale. Is the membrane continuous along these tubules, or does ...


1

I think you'll like this article. It's on monoamine release / reuptake inhibition for a host of different psychedelic and empathogenic drugs. This wakefulness inducing effect you describe for LSD is widely reported for all common 5-HT2 mediated psychedelics.


1

You're right, those are all important! There are several good reviews on the mechanism of action antidepressants. I like Molecular Pharmacology, by Nestler, or even Principles of Neural Science, by Kandel. I think a textbook is going to be your best bet, in terms of getting up to speed here, as this is largely an already-researched issue, but here are some ...


1

SSRI's theoretically increase Serotonin levels. Serotonin is an agonist to the 5HT-3 receptors. The 5HT-3a primarily associated with the upper gut and the 5HT-3b with the lower gut. I would guess that theoretically again, SSRI's would tend to increase nausea, emesis, and diarrhea. There may be other effects, but these are the ones I have researched. The ...


1

CB1 and CB2 are indeed particular genes which are present in neurons, but also liver and other tissues. The HGNC website is a good resource for questions like this - HGNC is the international organization that tries to unify and track gene names. The official gene names are CNR1 and CNR2 respectively. Gene names are a bit of a mess, since many genes have ...



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