A preclinical trial shows thatmain psychoactive compound in marijuana, the cannabinoid THC, improves learning and age-related memory deficits, at least in mice. These are the conclusions of the study published in the journal Nature Medicine by researchers from the University of Bonn Andras Bilkei-Gorzo and Andreas Zimmer.
The results also show that, on the contrary, the same treatment with this drug, which has a great addictive potential,would negatively affect behavior, memory and performance during learning in theyoung rodents.
The key to this effect, positive during aging and negative in earlier stages of life, would lie in the composition of plant THC itself and its analogy with certain substances that regulate the brain's immune system in a natural way, such asendocannabinoids, with whom THC would interact when consuming cannabis in old age.
Although it is still verysoon to determine if this research can be brought to the human clinic, the use of cannabinoids to treat neurological conditions such as epilepsy is already an active area of research. To these applications would now be added, the role of THC in brain rejuvenation and the treatment of diseases such as Alzheimer's.
“Several studies suggest that the activity of the cannabinoid system protects against brain aging. It is important to highlight that this activity decreases during aging, therefore, in the elderly, THC normalizes cannabinoid signaling ”, researcher Bilkei-Gorzo explained in statements to EL MUNDO.
On the other hand, “if we had a clinical study to find out if the treatment with THC 'rejuvenates' the brain of the elderly in the same way as it does in mice”, has stated Bilkei-Gorzo, “the probability of contracting a disease like that ofAlzheimer'sit could be reduced in patients receiving THC or cannabis treatment. "
A brain defense system
The biological mechanisms that produce aging are largely unknown and constitute one of the last frontiers of neuroscience. Neurodegenerative diseases and deterioration of the brain during this stage of life lead to amemory loss or a decline in thinking and attention span.
The speed with which we get older depends on the balance between the factors that favor the effect of time (errors in the functioning of the organism, mutations, accumulation of toxic substances, or cell death) and aanti-aging protection system that delays it.
In 2011, the team of scientists now led by Andreas Zimmer, a researcher at the Institute of Molecular Psychiatry at the University of Bonn, discovered that this defense mechanism acting in the brain is controlled by theEndocannabinoid System (ECS).
The ECS system encompasses a set of molecules called receptors that mediate communication between cells in the nervous system. The ECS behaves like a director of the nervous immune system, activating it and coordinating the degree of response that must be executed.
In the brain, this immune system is made up of different types of cells that continually inspect the environment in which neurons live. The so-called cells of themicrogliaand some star-shaped cells calledastrocytesassist, repair and sweep away harmful substances that could damage neurons and are acquired during aging.
In the face of a harmful stimulus, the presence of a pathogenic substance, or a lesion in the brain, an alert is triggered that activates the microglia and astrocytes to become operational andrepair the damage.
With age, the functioning of the ECS system can be altered and abnormally stimulate the immune response of the microglia and astrocytes. The consequence is a loss of neurons and inflammation of a part of the brain that is related to memory, thehippocampus. The symptoms are clear: deficit in the ability to learn, to adapt to new situations, and of course, memory loss.
The ECS receptors are also those that are going to be in charge of modulating the effect of psychotropic substances such asTetrahydrocannabinol(THC), which is present in the cannabis plant.
The Zimmer and Bilkei-Gorzo research team has now discovered that this drug restores cognitive function in old mice,returning the hippocampus to a state similar to that seen in young animals. It remains to be determined whether this model can be extrapolated to humans and other species.
“There is a very small difference in the distribution and activity of the cannabinoid system ofdifferent mammals. Only the density of cannabinoid receptors within brain areas shows some variability ”, has concluded Bilkei-Gorzo.Ecoportal.net
By Mar de Miguel, El Mundo