Cannabis: Olfactory Sensory System
By Dr. Denise A. Valenti at IMMAD, LLC
The goal of this activity is to demonstrate how simple identification tests of olfaction function using a set of twelve food odorants in extract form purchased from a local grocery store can be used as test of olfaction functioning. We tested four volunteers undosed and then dosed with their own cannabis products. The odorants are lemon, orange, lime, anise, peppermint, rum, butter (popcorn), cake batter, banana, maple, coconut, and raspberry. The food odorants of coconut and peppermint have been identified as being specific to COVID related olfactory dysfunction. Anosmia, or loss of smell is a common consequence of injury to the head and as well as an early sign of serious diseases, including Alzheimer’s Disease and Parkinson’s Disease. More recently anosmia is associated with the earlier variants of COVID and may be a long-term consequence.
Under an approved IRB specific to olfaction, we tested four volunteers already participating in unrelated research within the lab for cannabis research. The volunteers were first familiarized with each odor and then tested under blindfold for each odor. The procedure is done using a simple long cotton swab dipped into a sample of the odorant. The swab is then brought slowly to the nose and a recording is made of the distance of first detection of an odor, regardless of nature of the correctness of response. The volunteers then self-dosed under an IRB approved opportunistic dosing protocol and returned the lab and were retested.
The literature reports decreased functioning in olfactory response with cannabis use. We identified an increase in response ability, but a decrease in sensitivity. The trend (the use of only four volunteers does not allow for a project to be powered adequately) was for a decreased distance of response and a quicker response. But there was a poor ability to detect similar odors.
The use of cannabis changes sensory systems dopaminergic lateral sensitivity response in the retina. The same changes in dopaminergic response are likely going on in other sensory systems, including olfaction. This is evident in the trend toward poorer response to odors that would require neuroprocessing within lateral cell receptors such as dopaminergic cells.