I was going to go with the Parkison’s disease question because I thought it would be more interesting to discuss, but then when I read chapter 4 in the Pinel (2006) text I had to choose this one. Pinel (2006) offers the basic description of the difference between agonist and antagonist drugs as being that one type facilitates neurotransmitter interactions (agonists) while the other inhibits neurotransmitter interactions (antagonistic). In terms of agonists the two examples that the Pinel (2006) text gives are cocaine and benzodaizapines. Others that come to mind are nicotine, muscarine, l-dopa, and nerepinephrine.
There are just as many antagonists, such as apomorphine, curare, resparine, atropine, and my favorite botulinum toxins. I thought that it was interesting that the Pinel text refers to Botulinum toxin as BOTOX, which is a misnomer. BOTOX is actually a trade name for a particular type of botulinum toxin, type A to be specific, that is owned by one drug company. Additionally the text suggests that BOTOX is created by a bacterium often found in spoiled foods. While it is true that botulinum toxin can be found here, BOTOX, is actually only developed in a lab from the Clostridium botulinum bacteria. Additionally, while botulinum toxin contains only the neurotoxin itself, BOTOX actually contains both the toxin, as well as a heavey chain protein molecule which is what allows it to be transferred nonsystemincally into humans through injections. What is also of intestest that differentiates Botulinum toxin(s), I use plural because there are actually many of them, from BOTOX is the manner in which it affects neurotransmitter release. BOTOX is unique in the fact that it binds at the neuromuscluar junction and then severes SNAP-25 at the synaptic cleft thus preventing vesicles from their ability to release acetylcholine (Truong & Jost, 2006). There are actually several different types of commercially available botulinum toxins in addition to BOTOX, these...