Finals are around the corner, and many of us cope with extra study hours and gallons of coffee. As the day progresses, the brain uses its ATP, and the result is a buildup of adenosine. This biomolecule exits neurons and attached to two receptors, A1 and A2. A1 is responsible for decreasing the feeling of alertness, and the A2 receptor helps induce sleep. As a person recovers ATP through the night, the adenosine no longer binds to these receptors, and a signal to sleep is no longer present (Medicurio, 2017).
However, caffeine is an analog of adenosine. It binds to the receptors, competitively inhibiting the adenosine. Although it does not activate these receptors, the signal to sleep is never sent, as is the signal to decrease alertness (Medicurio, 2017). This mechanism allows a person to be alert and awake much longer, but as we have learned in physiology, the body is dynamic (Campisi, 2019). When people drink coffee often, they increase the amount of A1 and A2 receptors on the neuron surface. This is why it takes more coffee to get the same alert effect for a person who is a frequent coffee drinker (Medicurio, 2017).
A study published in the Journal of Psychopharmacology provided evidence that participants' reading speed was significantly increased as a result of caffeine intake. Even more interestingly, the participants with more significant sleep deprivation fared better on reading speed. One could argue that this is a great reason to stay up all night before an exam and drink copious amounts of coffee, but the study also shows that there is no increase in memory (Franceschini et al., 2019)!
Campisi, J. Homeostasis 8.26 [PDF document]. Retrieved from Lecture Notes Online Website: https://worldclass.regis.edu/d2l/le/content/238981/viewContent/3337560/View
Franceschini, S., Lulli, M., Bertoni, S., Gori, S., Angrilli, A., Mancarella, M., Puccio, G., & Facoetti, A. (2019). Caffeine improves text reading and global perception. Journal of Psychopharmacology. doi: 10.1177/0269881119878178.
Medicurio. (2017, April 6). Caffeine and Adenosine Receptors [Video file]. Retrieved from https://www.youtube.com/watch?v=jOfquPE1cnU
Christa,
ReplyDeleteLike other college students, I tend to drink coffee multiple times throughout the day to help me when I am in my physiological low point. After drinking the caffeine, I often feel more awake and alert while being able to focus on my assignments. A study completed in 2016 set out to test the effects of caffeine on memory performance in college students during their non optimal time of the day in the early morning (Sherman, Buckley, Baena & Ryan, 2016). Results showed that there was no significant difference between caffeinated college students and decaffeinated students in terms of wakefulness ratings, but there was a significant difference in memory performance between the two groups (Sherman, Buckley, Baena & Ryan, 2016). These results support the conclusion that caffeine benefits cognition during non-optimal conditions.
However, in terms of pulling an all nighter and drinking coffee before an exam you might want to reconsider. Sleep deprivation has been known to cause hippocampal disfunction, which is the area of the brain that involved in long term memory. Memory consolidation is a process in which information is stored in the brain and involves the processes of synaptic consolidation and synaptic consolidation (Havekes & Abel, 2017). Both of these processes are modulated by sleep and when an individual is sleep deprived there are negative effects on the hippocampus. This can be seen by the loss of synaptic plasticity as well as the degradation of cAMP and spine loss (Havekes & Abel, 2017).The decreased ability to store memories therefore could lead to a lower performance on exams.
References:
Havekes, R., & Abel, T. (2017). The tired hippocampus: the molecular impact of sleep deprivation on hippocampal function. Current opinion in neurobiology, 44, 13-19.
Sherman, S. M., Buckley, T. P., Baena, E., & Ryan, L. (2016). Caffeine enhances memory performance in young adults during their non-optimal time of day. Frontiers in psychology, 7, 1764.
Christa,
ReplyDeleteThis is a really interesting and relevant topic for the majority of us college students (especially considering that I'm sipping on a cup of coffee as I write this). For all the caffeine that I consume, I was never quite sure of the underlying mechanism behind how it affects the body. One study that I found concluded that caffeine intake 6 hours prior to going to bed has significant disruptive effects on sleep (Drake, Roehrs, Shambroom, & Roth, 2013). I know that I have been guilty on multiple occasions of consuming caffeine well within that 6-hour window, so I'm sure that the quality of my sleep has been compromised even without me always realizing it. It is really interesting that people who frequently consume caffeine actually up-regulate the A1 and A2 receptors on the surface of their neurons; I wonder if these individuals with a higher number of these receptors feel the alert effects of caffeine for a shorter amount of time and are able to have normal night of sleep after having caffeine at the 5 or 4 hour limit rather than 6 hours?
Resources:
Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. Journal of Clinical Sleep Medicine : JCSM : Official Publication of the American Academy of Sleep Medicine, 9(11), 1195–1200. https://doi.org/10.5664/jcsm.3170
Christa,
ReplyDeleteThis study is interesting and is also relevant to the working populations who tend to use caffeine as their morning wakeup habit. Hopefully the public can be aware of this information and use it to cut back on coffee addiction. But I am also curious on the effects of caffeine on students taking Dextroamphetamine / Amphetamine derivatives. How the physiological and biological systems and components affect each other? Especially since the statistics of ADHD in college students have increased and also the abuse of this drug among college to grad students is on the rise.
Resource
H. staff. (2016, February 16). Adderall abuse on the rise among young adults, Johns Hopkins study suggests. Retrieved December 3, 2019, from https://hub.jhu.edu/2016/02/16/adderall-abuse-rising-young-adults/.
Resources