Memory performance decreases with increasing age. Cannabis can reverse these ageing processes in the brain. This was shown in mice by scientists at the University of Bonn with their colleagues at The Hebrew University of Jerusalem (Israel). Old animals were able to regress to the state of two-month-old mice with a prolonged low-dose treatment with a cannabis active ingredient. This opens up new options, for instance, when it comes to treating dementia. The results are now presented in the journal Nature Medicine.
Like any other organ, our brain ages. As a result, cognitive ability also decreases with increasing age. This can be noticed, for instance, in that it becomes more difficult to learn new things or devote attention to several things at the same time. This process is normal, but can also promote dementia. Researchers have long been looking for ways to slow down or even reverse this process.
Scientists at the University of Bonn and The Hebrew University of Jerusalem (Israel) have now achieved this in mice. These animals have a relatively short life expectancy in nature and display pronounced cognitive deficits even at twelve months of age. The researchers administered a small quantity of THC, the active ingredient in the hemp plant (cannabis), to mice aged two, twelve and 18 months over a period of four weeks.
Afterwards, they tested learning capacity and memory performance in the animals – including, for instance, orientation skills and the recognition of other mice. Mice who were only given a placebo displayed natural age-dependent learning and memory losses. In contrast, the cognitive functions of the animals treated with cannabis were just as good as the two-month-old control animals. “The treatment completely reversed the loss of performance in the old animals,” reported Prof. Andreas Zimmer from the Institute of Molecular Psychiatry at the University of Bonn and member of the Cluster of Excellence ImmunoSensation.
Years of meticulous research
This treatment success is the result of years of meticulous research. First of all, the scientists discovered that the brain ages much faster when mice do not possess any functional receptors for THC. These cannabinoid 1 (CB1) receptors are proteins to which the substances dock and thus trigger a signal chain. CB1 is also the reason for the intoxicating effect of THC in cannabis products, such as hashish or marihuana, which accumulate at the receptor. THC imitates the effect of cannabinoids produced naturally in the body, which fulfil important functions in the brain.
“With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces,” says Prof. Zimmer. “When the activity of the cannabinoid system declines, we find rapid ageing in the brain.”
To discover precisely what effect the THC treatment has in old mice, the researchers examined the brain tissue and gene activity of the treated mice. The findings were surprising: the molecular signature no longer corresponded to that of old animals, but was instead very similar to that of young animals. The number of links between the nerve cells in the brain also increased again, which is an important prerequisite for learning ability. “It looked as though the THC treatment turned back the molecular clock,” says Zimmer.
Next step: clinical trial on humans
A low dose of the administered THC was chosen so that there was no intoxicating effect in the mice. Cannabis products are already permitted as medications, for instance as pain relief. As a next step, the researchers want to conduct a clinical trial to investigate whether THC also reverses ageing processes in the brain in humans and can increase cognitive ability.
The North Rhine-Westphalia science minister Svenja Schulze appeared thrilled by the study: “The promotion of knowledge-led research is indispensable, as it is the breeding ground for all matters relating to application. Although there is a long path from mice to humans, I feel extremely positive about the prospect that THC could be used to treat dementia, for instance.”
Publication: A chronic low dose of delta9-tetrahydrocannabinol (THC) restores cognitive function in old mice, Nature Medicine, DOI: 10.1038/nm.4311
Prof. Andreas Zimmer
Institute of Molecular Psychiatry
University of Bonn
Tel. +49 (0)228/6885300
Johannes Seiler | idw - Informationsdienst Wissenschaft
Usher syndrome: Gene therapy restores hearing and balance
25.09.2017 | Institut Pasteur
MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer
25.09.2017 | Case Western Reserve University
Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
26.09.2017 | Life Sciences
26.09.2017 | Physics and Astronomy
26.09.2017 | Information Technology