Neuralink, Elon Musk’s backed Brain Computer Interface company, is looking for a clinical trial director. Indeed, they have dozens of open positions and a very attractive website. This company aims at building a BCI system that can be used to help patients communicating through text and daily life devices. Initially, Musk has proposed that with this device, one could top up one’s own brain capacity. However, this seems to be more suited as the topic of science fiction than of real-life. Hence, the goal has been tweaked down a notch.
As with any other medical component, medical devices must go through highly regulated control and scrutiny. Among others, it must be shown that the device does not disturb brain homeostasis. This is quite difficult to prove, as (per figure below) it is quite easy to disturb the brain. Imagining a surgery to implant a device like the “link”, neuronal death and blood-brain-barrier dysfunction (opening) starts within minutes of the 1st procedure. Moreover, all other cells are affected within hours, with the activation of astrocytes and microglia, and scarization being the most important aspects. Not surprisingly, the immune system gets activated very early on as well, with macrophages and neutrophils being on the first line of response. A consequence of normal process of macrophage is that these cells become tissue resident macrophages. In the brain, it means that they become “microglia-like”, which makes a chronological timeline of events difficult to understand. As an example, if a device that has been implanted for four months has triggered an immune response at three months, when you collect the samples at 3.5 or 4 months, most macrophages that were triggered with the first event will now have differentiated into microglia – a typical brain cell. Hence, based on this observation alone, one would not be able to detect a problem.
Even if most of these processes tend to stabilize over-time, they stabilize away from their basal level. Hence, appropriate control groups and time points must be chosen, so to understand the impact of a new device in brain homeostasis.