The Effect of Cannabidiol (CBD) on the Short-Term Memory of young Drosophila melanogaster Research that is focused on memory is prominent in modern times because age-related memory loss is a The beneficial properties of cannabidiol (CBD) are being studied and celebrated. Recent scientific evidence shows that CBD can help promote better memory function.
The Effect of Cannabidiol (CBD) on the Short-Term Memory of young Drosophila melanogaster
Research that is focused on memory is prominent in modern times because age-related memory loss is a growing issue throughout the world. Previous research has suggested that cannabidiol (CBD) can improve the memory of the elderly suffering from neurodegenerative diseases. However, the effect that CBD has on the memory of young people has not been extensively studied. Here we show that CBD does not improve the short-term memory of young male D. melanogaster. Our finding has contradicted the known knowledge of how CBD could potentially be used for memory loss. Our results suggest that exposure to CBD may result in impairment of the short-term memory and cause erratic behavior in young organisms. These outcomes could be a starting point for future study on the effect that CBD may have on young humans.
Memory plays a major role in adapting to a habitat and acquiring various skills. Learning is essential for memory, and memory allows organisms to recall the information they learned and use it whenever they need to. There are two main types of memories pertaining to humans: long-term and short-term memory (Cowan, 2008). Long-term memory is a remembrance of events that have taken place at an early time of one’s life and cannot be forgotten easily. Short-term memory is the remembrance of actions or events that have occurred recently and can be forgotten quickly (Cowan, 2008). There are important factors that can cause damage to short-term memory such as aging, physical injury, and substance abuse. Short-term memory impairment increases as humans age. Throughout the world, there is an estimate of 50 million people with dementia. This number is expected to grow by 10 million cases every year (World Health Organization, 2020).
Substance abuse has been a growing issue throughout the world. One of these substances is Cannabis, found in the Cannabis sativa plant, and is commonly known as Marijuana. Two major components found in Cannabis are Cannabidiol (CBD), which is not a mind-altering component and Tetrahydrocannabinol (THC), which is a mind-altering component (Schoeler and Bhattacharyya, 2013). CBD has several positive effects on the human body, such as reducing neuroinflammation, reducing brain damage caused by neurodegenerative diseases, promoting the production of new neurons in the brain, and raising levels of synaptic plasticity in the brain (Maroon and Bost, 2018). However, there are negative effects of CBD which include irritability, extreme tiredness, and nausea (Grinspoon, 2018). Previous studies have stated that CBD can improve the memory of people over the age of 65 with neurodegenerative diseases (McGuire et al., 2017). Currently, there is not a large amount of research on how CBD affects the memory of people under the age of 25 years old.
The current study aims to test if CBD improves the short-term memory of young male Drosophila melanogaster, commonly known as fruit flies. This organism is ideal for this study as it is easy to maintain, and it reproduces fairly quickly. Drosophila also have a short life span, which allows us to study short-term memory in a limited period of time. We hypothesized that exposure to CBD may improve the short-term memory of the male D. melanogaster when the aversive phototaxic suppression assay (APSA) is performed.
Materials & Methods
Fly stock and rearing conditions
A wildtype D. melanogaster Oregon R is used in this study. Flies were reared in tubes containing cornmeal media. They were flipped into fresh media every three weeks and were kept in a 20oC chamber. For this study, we used flies that were up to two weeks old.
Pilot Study: Testing the Amount of CBD To Use
Prior to performing the experiment, the amount of CBD oil (Fisher Scientific, 1 mg/mL CBD in 1 mL ethanol or methanol) that the flies were exposed to was determined by exposing the flies to fly food that contained differing amounts of CBD. The flies consumed food that contained 0.4 mL, 0.2 mL, 0.1 mL, 0.075 mL, or 0.050 mL of CBD. The CBD was mixed into the food along with 2 mL of water. Based on our data, we decided that 0.050 mL of CBD (0.025 M CBD solution) was appropriate for our experiment. The control was the same amount of ethanol without CBD.
Pilot Study: Testing the Experimental Apparatus
Figure 1. This apparatus used for the phototaxis test and APSA test. Quinine hydrochloride solution was applied on the inside of the lighted tube (left). It was used to test whether the fly was sighted or not, was used for the learning and short-term memory tests.
The efficiency of the experimental apparatus we made for the current study was tested (Fig.1). Tube 1 contained 1.8 g of fly food, 2 mL of 1MΩ water, and 0. 05 mL of CBD solution. Tube 2 contained 1.8 g of fly food, 2 mL of 1MΩ water, and 0.05 mL of 95% ethanol as the control. The fly food containing ethanol was used as our control because the CBD was dissolved in ethanol. The students transferred 3 young flies into each tube, so they were exposed to these food conditions for 24 hours, and then the Aversive Phototaxic Suppression Assay was performed on each fly for 6 trials.
Your browser does not support the video tag.
The phototaxis test examines an organism’s innate ability to move towards light (Nakamura and Yamashita, 1997). Each fly was transferred into a dark tube, which was covered in aluminum foil, and then the room was made dark. The fly was allowed to acclimate to the dark for 1 minute. Another tube was then connected to the dark tube, and a light was flashed from above on to the tube that was not covered in aluminum foil (lighted tube). The fly was given the option to move to the lighted tube or stay in the dark tube. The fly that was positively phototaxic moved towards the light (Nakamura and Yamashita, 1997) if they were sighted within 30 seconds. We performed the phototaxis test to eliminate the blind flies (or those with abnormal visual function) for the APSA.
Aversive Phototaxic Suppression Assay (APSA)
Your browser does not support the video tag.
This test trained the fly to remain in the dark side of the apparatus (Seugnet et al., 2009). Prior to the Aversive Phototaxic Suppression Assay (APSA), the flies were exposed to either diets (CBD-infused food or control food) for 24 hours. Then they were starved for 6 hours before starting the Aversive Phototaxic Suppression Assay. In this assay, two plastic tubes were used, one was covered in aluminum foil to create darkness and the other one was left uncovered. The uncovered tube was coated with a 1M solution of quinine hydrochloride, a bitter substance that repels the flies (Hayes et al., 2015). Each fly was transferred to the dark tube, the room was made dark, and the fly was allowed to acclimate to the dark for 1 minute. The uncovered tube containing quinine was then connected to the dark tube. A white light from a smartphone device was flashed on the uncovered tube and immediately a timer was started when the two tubes were connected. The timer was stopped once the fly touched the quinine on the lighted side of the tube. The students performed 10 trials and after each trial, the fly was tapped back into the dark tube and was allowed to rest for 30 seconds and re-acclimate to the darkness. After the learning test was performed, the flies were starved again for 6 hours so that their short-term memory could be tested. The memory test was just one trial. It is the same procedure as the learning test to determine if the flies remember what they had learned 6 hours ago.
First, we measured how many trials it took for the young male flies to learn. To do this, we performed the APSA (Materials and Methods). During the 10 trials, the flies exposed to the control food did not show a significant change until the 7th trial (Fig. 2b). There was a significant difference after the 8th trial. We interpreted this as the flies in the control group learned at the 8th trial. In the CBD treatment group, we found that the flies did not show a significant change throughout all 10 trials (Fig. 2c). We interpreted this as the flies in the CBD group did not learn at all.
We found that there was a wide variation of average avoidance times for each trial. (Fig. 2c) This could be the result of the CBD effect on the flies. We observed that some of the young male flies that were exposed to the CBD-infused food had very erratic behavior, which is described by abnormal movements of the flies, while others had sluggish or normal behavior. This could explain why the average avoidance times varied.
Second, we tested the effect of CBD on their short-term memory. To do this, the flies were starved for 6 hours and then the APSA was repeated once (Materials and Methods). We found that the flies exposed to the control food did not surpass the threshold avoidance time (Table 1). We interpreted this as the flies not remembering what they had learned. In the CBD treatment group, we could not calculate a threshold avoidance time because the flies did not learn throughout the 10 trials of the learning test. Therefore, since the flies did not learn, it is impossible for them to have remembered.
Table 1: Table shows the results of the memory test for flies exposed to control and CBD-infused food. The threshold avoidance time for the control group was 112.9 s. The threshold avoidance time was calculated by taking the average of the averaged trials that the flies learned in. (Threshold for control flies: average of the mean trials 8, 9, and 10). The flies whose avoidance times passed this threshold remembered what they learned. According to the learning test results, none of the control flies remembered what they learned. The flies exposed to CBD-infused food did not learn, so they do not have a threshold avoidance time. Since the flies did not learn, they did not remember.
This study focuses on the effect of CBD on young male D. melanogaster’s short-term memory. In order to do this, APSA was performed to observe whether a CBD-infused diet improved their learning or not. Using the APSA, 10 trials were conducted for the learning test, and then a 6-hour starvation gap was given before performing only one trial of the APSA again to test their memory. Figure 2 shows the results of the APSA tests for the control and CBD treated flies. We hypothesized that the CBD group would learn quicker than the control group. However, our results showed that the flies in the CBD group did not learn at all. Fig.1b shows a graph of the 10 trials of the learning test for the flies exposed to control food. The results of the Kruskal-Wallis test showed that trials 1-7 showed no significant learning in the flies (p>0.05), and trials 8-10 showed no significant learning in the flies (p>0.05). A Mann-Whitney test was done comparing trials 1-7 to trials 8-10 (p<0.05). This shows that the flies did not learn at the 8th trial as the control flies did. Also, since the results of the learning test in the CBD treated flies was erratic, we concluded that the flies did not learn at all during the 10 trials.
Fig.1c shows a graph of the 10 trials of the learning test for the flies exposed to CBD-infused food. The results of the Kruskal-Wallis test showed that trials 1-7 had no significant learning in the flies (p>0.05), and trials 8-10 showed no significant learning in the flies (p>0.05). A Mann-Whitney test was done comparing trials 1-7 to trials 8-10 (p>0.05). This shows that the flies did not learn at the 8th trial as the control flies did. Also, since the results of the learning test in the CBD treated flies was erratic, we concluded that the flies did not learn at all during the 10 trials.
Figure 2: Results of the Phototaxic Suppression Assay. a) Graph comparing the average avoidance times for each trial in the learning tests for male D. melanogaster in the control and CBD diets. b) Graph showing the 10 trials of the learning test for the flies exposed to control food (n=3). The p-values show that the flies learned at trial 8 (p<0.05). c) Graph showing the 10 trials of the learning test for the flies exposed to CBD-infused food (n=4). The p-values show that the flies did not learn at any trial.
Finally, we repeated one trial of the APSA 6 hours after the learning tests to determine if the flies remembered what they had learned. The threshold avoidance time for the flies exposed to the control food was 112.9 seconds (Table 1). Since none of the flies exposed to the control food surpassed the threshold avoidance time during the memory test, we conclude that none of them remembered what they had learned. A possible reason for this could be that the ethanol had a psychiatric effect on the flies that impaired their short-term memory. For the CBD group, it was impossible to calculate a threshold avoidance time because they did not learn. As a result, we cannot make conclusions about the CBD treated flies’ memory since they did not learn. However, it is interesting to note that fly 1 and fly 2 had a higher avoidance time compared to fly 3 and fly 4 (Table 1). Here, 2 groups can be seen, one group where there is high avoidance time and one group where the avoidance time is low. We assume there may be a psychiatric effect on each fly causing each one to behave differently compared to another fly. The CBD may not be 100% pure and may contain another major component of cannabis called tetrahydrocannabinol (THC) which has a mind-altering effect. This may be a reason why the flies behaved in a contrasting manner. Another factor could be that the flies may have had a genetic variation that was contributing to affecting each fly differently.
We conclude that CBD has an inhibitory effect on the short-term memory of male Drosophila melanogaster as they did not learn during the learning test nor did they remember during the memory test. We found that time was an essential component to perform this experiment. We were also researching other variables such as sex difference and age difference, but our sample size was too small due to the death of many flies.
The authors would like to thank Dr. Kwangwon Lee and Dr. Nathan Fried for their guidance and support, Sarah Johnson for ordering supplies, Taqdees Gohar for assisting with the experimental plan, and Harjit Khaira for providing fly supplies and advice.
Hayes, J.E., Feeney, E.L., Nolden, A.A., and McGeary, J.E. (2015). Quinine Bitterness and Grapefruit Liking Associate with Allelic Variants in TAS2R31. Chem. Senses 40, 437–443.
Ki, Y., and Lim, C. (2019). Sleep-promoting effects of threonine link amino acid metabolism in Drosophila neuron to GABAergic control of sleep drive. ELife 8, e40593.
Nakamura, T., and Yamashita, S. (1997). Phototactic Behavior of Nocturnal and Diurnal Spiders: Negative and Positive Phototaxes. Zoolog. Sci. 14, 199–203.
Seugnet, L., Suzuki, Y., Stidd, R., and Shaw, P.J. (2009). Aversive phototaxic suppression: evaluation of a short-term memory assay in Drosophila melanogaster. Genes Brain Behav. 8, 377–389.
Wong, R., Piper, M.D.W., Wertheim, B., and Partridge, L. (2009). Quantification of Food Intake in Drosophila. PLoS ONE 4.
McGuire, P., Robson, P., Cubala, W.J., Vasile, D., Morrison, P.D., Barron, R., Taylor, A., and Wright, S. (2017). Cannabidiol (CBD) as an Adjunctive Therapy in Schizophrenia: A Multicenter Randomized Controlled Trial. AJP 175, 225–231.
Schoeler, T., and Bhattacharyya, S. (2013). The effect of cannabis use on memory function: an update. Subst. Abuse Rehabil. 4, 11–27.
Does CBD Affect Memory Function?
Recent studies show that a single dose of CBD can have a multitude of benefits for the user.
CBD, or cannabidiol, is known to help reduce symptoms associated with muscle and joint swelling, ease skin irritations, aid in disrupted sleep cycles, relieve tension, and support mental health.
With these incredible effects of CBD, it will not enact a psychotropic effect on the body and mind like another cannabinoid derived from the Cannabis sativa plant, Δ-9-Tetrahydrocannabinol (THC).
Instead of causing psychoactive effects, CBD has a more subtle effect on the brain that can benefit our wellbeing and even play a role in memory function.
How Does CBD Work Within The Body?
Both THC and CBD interact with the body’s endocannabinoid system (the ECS), which helps regulate balance throughout the body’s multiple systems.
The endocannabinoid system uses naturally produced chemical messages known as endocannabinoids to communicate.
These endocannabinoids can bind with cannabinoid receptors (CB receptors) found in the brain and the nervous system to activate various biological functions, such as increased hormone production, working memory, or brain cell activity within the hippocampus.
How Is CBD Different From THC?
While THC and CBD share the same molecular formula makeup, which is 21 carbon atoms, 30 hydrogen atoms, and two oxygen atoms, their molecular arrangement sets them apart. Their molecular mass is nearly identical, but a slight variation in their molecular formation leads the two to play very different roles within the ECS.
CBD cannot be psychoactive because of how it is built. The molecular structure will not allow it to bind with the endocannabinoid system’s CB1 receptors the way THC does. This allows the two phytocannabinoids to affect the brain in different ways.
While THC can have the reputation of causing memory loss, recent studies have revealed that CBD might have the opposite effect. It is a non-intoxicating substance that can improve memory retention consolidation.
How Does CBD Improve Memory Function?
CBD is a chemical compound that is naturally derived from the cannabis plant. It hosts many practical medical and therapeutic health benefits without producing the high or potentially harmful feelings associated with THC’s psychoactive effects, such as psychosis, nervousness, paranoia, or increased heart rate.
While CBD doesn’t bind directly with CB receptors in the brain, it can still support endocannabinoids that do bind with cannabinoid receptors, and has been found to interact with other receptors and neurotransmitters throughout the brain.
The effect of cannabidiol (CBD) function within the brain is believed to help improve memory function and prevent memory deficits in several ways.
CBD is considered neuroprotective, meaning it can help protect the neurons responsible for maintaining cognitive function from damage or degeneration. This can play an essential role in memory function and support those with memory and cognitive impairment.
A 2016 study found sufficient evidence that regular cannabis use can help slow or potentially reverse the loss of memory function associated with dementia by helping protect vital neurotransmitters and brain tissue. The study also found that CBD may support memory function and reduce memory impairment by helping increase the connection between brain cells. These results have been validated by clinical trials and research from additional laboratories.
As an antioxidant, CBD can help reduce oxidative stress within the body, which is known to damage healthy cells. Research has shown that oxidative stress can help reduce memory processing and retention by degrading brain cells.
Memory function capabilities decrease as more oxygen is released inside of the brain. CBD’s antioxidant properties can help reduce problems associated with oxygen stress. By utilizing CBD, brain functions that are negatively impacted by increased oxygen levels in the brain can be improved.
The body also becomes less capable of combating oxidative stress on its own as we age, meaning our cells have less natural protection from oxidative stress over time. By reducing the risk of oxidative stress as we age, CBD can help protect our brain cells, which in turn protects our memory function.
Reduce Stress Levels
High stress levels can impact memory function. When we are stressed, our brains have more trouble creating short-term memories and have a more challenging time translating short-term memories into long-term ones.
The good news is that using CBD can relieve the user from feelings of stress, tension, and discomfort from physical movement. For someone living with certain health conditions, the common effects of cannabis include helping ease the symptoms of stress and tension, improving motor functions, and reducing memory decline.
The soothing properties of CBD suppress agitation, allowing the user to calmly focus on the tasks at hand. This can help the brain better recall memories, as it takes away the stress associated with the struggle to remember.
Using CBD can also relieve symptoms associated with memory disturbances. When the brain’s immune cells fail to clear dead brain cells, blockages in neural pathways occur. The more swelling there is, the more significant the impact will be.
Swelling in the brain has been associated with neurodegenerative disorders, cognitive decline, and memory loss. But thanks to its anti-swelling properties, CBD can help reduce swelling and increase blood flow in the brain, helping to reduce the risk of memory loss.
Limonene Terpenes And Memory Function
Terpenes are compounds found in nature, particularly in plants, responsible for their fragrance, taste, and medical properties.
Limonene terpenes, which are terpenes derived from citrus fruit, are the second most widely distributed terpenoid found in nature. These terpenes are bio-identical to CBD that are from a cannabis or hemp plant.
Limonene terpenes that are transformed into essential oils have been utilized as a holistic remedy for centuries. Regular usage can improve the quality of life in many different ways, especially for those struggling with memory function.
Scientific clinical studies suggest that citrus oil, due to the limonene terpenes, has soothing effects on the body and mind comparable to the impact of CBD derived from cannabis or hemp. It is a very safe ingestible substance that is also shown to soothe the gastrointestinal process for improved digestion.
Citrus oil also has been shown to have a calming effect on the mind, allowing for relaxation and improved focus. This will overall help with maintaining healthy memory function.
Scents trigger the olfactory system, which controls the body’s sense of smell. The olfactory sensors then trigger the emotional and memory centers of the brain. This is why smell is so closely related to memory and nostalgia. Just breathing in limonene terpenes in a citrus essential oil can evoke a calming response throughout the body.
Peels CBD Oil: CBD Without the THC
Using CBD has been shown to improve cognitive facial recognition skills when administered alone, without any THC compounds or impurities added. The addition of hemp, THC, pesticides, heavy metals, and mycotoxins are all too commonly present in CBD products that are derived from the cannabis plant.
These additions can detrimentally alter sought-after results regarding using CBD to aid memory function. That is why it is vital to do your research and choose a product that is as healthy and clean of impurities as possible.
Peels CBD Oil is made from terpenes found in orange peels. It is a natural substance that is absolutely guaranteed to be the purest and safest CBD oil on today’s market.
Peels CBD is known as nature-identical, which means it is the same as CBD found in a cannabis or hemp plant. Due to its origin being orange peels, there is zero hemp or THC content in its formula.
This pure tincture will allow for optimal benefits for the user in that additional and detracting ingredients and compounds will not muddle.
Peels CBD is odorless and tasteless in its raw form. In addition to organic medium-chain triglycerides (MCT) oil (from coconut), our tinctures have a distinctive citrus flavor and aroma due to our organic, natural citrus flavor. There is no hemp or cannabis-related smell or taste because our CBD is not derived from either of those sources.
Like CBD derived from the cannabis plant, both kinds describe a cannabinoid made through synthesis, which is chemically and molecularly identical to the same cannabinoid found in nature.
Our process of taking CBD from natural inputs guarantees zero THC and hemp content in our products. Everything that goes into the process is found in nature, and everything that comes out of our process is found in nature.
How To Use Peels CBD
Peels CBD Oil comes in tincture form, which is a concentrated herbal extract. Simply place a dropper full of CBD under your tongue, release your preferred dosage, and then hold it under the tongue for 30-60 seconds before consumption. This will speed up the absorption time in the body.
Try adding your CBD drops into your coffee, breakfast, or morning smoothie. With sublingual administration, CBD can begin to release its effects after only 30 minutes.
When consumed with food or drink, they will take the same amount of time as ingesting an edible. Since CBD is a fat-soluble compound, taking CBD with a high-fat meal will increase absorption.
CBD And Daily Life
CBD emits benefits that soothe the body and calms the mind. Regular CBD use supports full-body wellness.
Physically, CBD has been known to soothe joint discomfort and muscle tension temporarily. This is especially wonderful if you are an athlete or prone to recurring aches.
Mentally, CBD brings peace and calm to the stress hormones in the body, allowing you to think clearer and focus on your tasks at hand. It relieves the stress response in the body and creates a literal inner sense of balance, or homeostasis, within.
CBD is also used to help get a good night’s rest. While smaller doses of CBD are used as wakefulness and focusing agents, a slightly larger dose has been shown to have sedative effects.
As the brain works on memory processing and storage while you sleep, quality slumber is essential to the brain’s optimal memory function. By falling asleep and staying asleep, you set your brain up for success in its memory comprehension and storage systems.
CBD supports sleep by removing discomfort in the mind and body, creating a relaxed sense of peacefulness. It eases tension in the head, neck, and achy muscles or joints.
Emotionally and mentally, CBD will soothe any feelings of stress that might keep you up at night.
While there is still so much research that needs to be conducted regarding the relationship between CBD and memory, scientific studies support the findings that CBD increases region-specific blood flow in the brain, something that had previously been disputed.
By increasing blood flow to specific areas of the brain, those brain systems will be able to function quickly and efficiently.
Since it is safe and generally well tolerated with minimal side effects, it is an excellent option for a holistic and natural CBD treatment.
The nature of CBD is complex, and so much is still yet to be discovered. However, these scientific findings can advance further research in a range of medical conditions characterized by how the brain processes memory and function.