Niamh McGuinness is a PhD candidate at the Trinity College of Neuroscience. Her studies are focused on the role of endocannabinoids in Alzheimer’s disease. Alzheimer’s affects 1/20 people over the age of 65 and ⅕ people over the age of 80. Niamh informs us that Alzheimer’s is caused by a widespread loss of neurons, a cell found in the brain. Neurons in the part of the brain associated with memory are specifically affected, hence the cognitive decline associated with Alzheimer’s.
The death of these neurons is caused by small toxic aggregates of a protein called amyloid beta or more colloquially plaques. Alzheimer’s disease is driven by the production of amyloid beta or plaques. The plaques gather around neurons causing them to die. Amyloid beta also causes tau protein hyperactivity. Tau protein is linked with two different kinds of lesions. These are:
Neurofibrillary tangles and amyloid plaques protein buildups. They occur naturally during the ageing process, but the amount of these in Alzheimer’s patients is much higher. Amyloid plaques (senile plaques) are made of small beta amyloid deposits. Beta amyloid slowly become stick together and eventually develop into plaques.
Tau protein is formed in neurofibrillary tangle (NFT). Nerve cells or neurons have something called microtubules. In Alzheimer’s patients the molecules divide into filaments and these become tangled. These tangles are called neurofibrillary tangles.
The plaque also interferes with the lysosome. The lysosome is the recycling centre of the brain. As such, it contains chemicals, called hydrolytic enzymes, to break down the waste of the cells. The hydrolytic enzymes are within the lysosome membrane which has a proton pump to maintain its acidic environment. The plaques cause these lysosome contents to spill into the neuron and thus kill it.
The lysosome is a subcellular organelle (part of a cell) and is found in all cells with a nucleus. Lysosome serves an essential purpose. It is responsible for the digestion of macromolecules, old cell parts, and microorganisms. Macromolecules include things like:
Cannabinoids are found in most complex plants and animals. However, the most famous cannabinoids, cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC)our endocannabinoid system (ECS). The ECS maintains bodily homeostasis when balanced. The ECS controls mood, appetite, memory, skin care, our immune system, etc. We are able to increase our cannabinoid level to reach homeostasis by ingesting medical cannabis. It has been found that cannabinoids can slow the breakdown of the lysosome in Alzheimer’s. Alzheimer’s patients with rapidly declining cognitive ability, have a simple solution of medical cannabis could elongate their life and increase their memory preservation.
In the cases of neuroinflammatory disorders, including Parkinson’s disease, Huntington’s disease and multiple sclerosis, far more is known about the role of the endocannabinoid system. In the case of Alzheimer’s disease there is a low availability of animal models that are relevant to the human disease. There is also a general complexity of Alzheimer’s compare to that of other neurological disorders. Even with the lack of research, the small levels of available data suggest the ECS plays a role in Alzheimer’s disease similar to the role it plays in other neurodegenerative diseases. Novel studies into medical cannabis are being launched more and more. As more research on Alzheimer’s and cannabis is published, we await news on the potentiality for cannabis to greatly improve the quality of these patients lives.