Am I spacing out..? or is it because of my genes?
When I was in high school, I was always interested about the effects that certain neuromodulators had on behaviour. One of the areas that intrigued me the most were the areas of learning & memory. I always had trouble remembering a lot of the critical facts I needed to know for assignments or exams & I wanted to find the root of that. When I was in my senior year, I learned about the study done on the function of acetylcholine on memory in rats by Martinez & Kesner (1991). This study revolutionized my view of the field of psychology (neuropsychology and neurobiology in particular) because it scientifically strengthened a belief that I had even before I started taking psychology academically — that memory was influenced by biological factors beyond our control.
In their study, Martinez and Kesner (1991) used lab rats in order to test the role of acetylcholine on the formation and subsequent storage of memory. What Martinez & Kesner (1991) did is that they injected one group of rats with scopolamine, which blocks acetylcholine receptor proteins on the post-synaptic neuron, meaning that no acetylcholine related nerve impulses are sent through the neuron. The second group was injected with physostigmine, an antagonist of acetylcholinesterase, which cleans up acetylcholine rom receptor proteins on the post-synaptic membranes. Physostigmine being injected into the post-synaptic membrane means that acetylcholine reuptake would be prohibited, predicting that memory formation and storage in the 2nd group of rats would be stronger. The third group was not injected at all and in some cases were injected with a placebo, meaning that there would not be an expected change in behavior. The experiment was a classic laboratory experiment with 3 controlled variables: the complexity of the maze the rats had to go through, the 3 different neurotransmitter (or placebo) conditions and the different neurotransmitter quantities. The results that Martinez & Kesner (1991) received were that the rats that were injected with scopolamine took the longest in order to complete the maze (because they were incapable of remembering it), while the rats that were injected with physostigmine were the fastest to complete the maze. The rats in the placebo group were in between the two other groups in terms of speed. These results show that acetylcholine and acetylcholinesterase (as well as physostigmine and scopolamine) have a role in memory formation and storage in rats, but through triangulation Martinez & Kesner deduced that these neurotransmitters had an effect on memory formation & storage in humans as well.
This blog revolutionized my view of psychology and it is the reason as to why I study psychology today. The implications related to this study not only extend to non-homosapien animals but also to humans. This study could provide major advancements into the fields of attention hyperactivity disorder (ADHD) and also in the field of memory & concentration, which would restructure the way we view memory in both humans and non-human animals. It is critical for people to understand the effects of these neurotransmitters and neuromodulators in order for people like me to find out if they are merely memory defective or if they have a serious problem in the synthesis or expression of neuromodulators in their system. The beauty of memory is fascinating, but when someone has a defect it is imperative to know the effects that that has on human behavior, learning & memory.
