OrganEx, Sleep & Memory, Cardiomyocytes & Exercise, and L9LS

Last Week in Medicine

Melih Gönenli
3 min readAug 7, 2022
Photo by Piron Guillaume on Unsplash


When our cells lack oxygen for a certain time, they eventually die, but we can reoxygenate them before it happens. This has a side effect, unfortunately, called ischemia-reperfusion injury. The “BrainEx” technology, invented by Vrselja et al. uses a cytoprotective perfusate to restore cellular functions in pig brains with reduced reperfusion injury.

What’s new is a paper on Nature that adapts BrainEx to other organs, called “OrganEx”. Andrijevic et al. created a new perfusate for the whole body. They were able to perfuse a pig’s organs for 6 hours.

If human studies can be made, these experiments can change organ transplantation methods, cardiac arrest and stroke treatment strategies, and the determination of death.

Sleep and Memory

As a known fact, sleep is crucial to memorise what we learnt throughout the day. But what mechanism relies behind this process was not known before. A new paper on The Journal of Neuroscience written by Tadros and Bazhenov, provides a model for this.

Their study says that, on non-REM sleep phase, memory traces learned in awake were replayed. This provokes new relational memories.

Cardiomyocytes and Exercise

Cardiomyocytes, cells in our hearts, have limited capacity to renew. Especially with age, this ability becomes less and less. Researchers found that with exercise, cardiomyocyte production can be induced in the young adult mouse heart.

Same researchers, Lerchenmüller et al. wrote a new paper on Circulation that says cardiomyogenesis can be simulated in aged mice too. They compared 5 aged sedentary mice with 5 aged exercised mice and found that cardiomyogenesis is significantly higher in exercised ones. They say “… exercise induces pathways related to circadian rhythm, irrespective of age”.

A new paper on NEJM written by Wu et al. introduces a new anti-malarial monoclonal antibody, L9LS. They present phase 1 results. They applied L9LS intravenously or subcutaneously to healthy adults. Within 2–6 weeks, 17 L9LS participants and 6 control participants underwent controlled malaria infection. Results say, 15 participants who received L9LS were protected. Parasitemia was developed in 2 L9LS participants and all control participants.

Ketamine is used for inducing general anaesthesia, treating pain, depression etc. and moderately addictive. Simmler et al. founded that ketamine is low-addictive by a dopamine-driven positive reinforcement.

Unlike cocaine and other addictive drugs, Ketamine does not induce synaptic plasticity. Distinctly it has a dual action of disinhibition of dopamine neurons and termination of the same mechanism.