No, don't worry, psilocybin doesn't make real mushrooms grow in the brain - but structures similar to mushrooms, so-called spines. 

This is what scientists at Yale University found out in a recent study and see in it a further explanation for the therapeutic effects of the active ingredient psilocybin in depression.
But first, what are spines anyway?

They are small protuberances that sit on the surface of the nerve cells in our brain (recognizable as the small bubbles in the enlarged section - slide 1). They play a crucial role in networking and communication between nerve cells, because they are not only responsible for receiving signals from other cells, but can also amplify them.
In short, they support the transmission of information in the brain.

Using a laser scanning microscope, Ling-Xiao Shao et al. 2021, tracked changes in precisely these structures over several days in living mice. They did this by taking high-resolution images of the neurons at different time points (as seen in Slide 2) before and after the administration of a dose of psilocybin.

They found that the number of spines and their overall size increased within 24 hours of psilocybin administration, and these changes were still present a month later (The change can be seen clearly in the example of a cell studied, as shown in Silde 3). 

The scientists were able to show that this resulted in an increase in neuronal connections overall, and at the same time these were on average 10% larger, i.e. the new connections were also stronger.

Since it is known from previous studies that chronic stress and depression in particular lead to a reduction in the number of spines and thus to impaired information transmission, the findings from this study could be an explanation for the lasting therapeutic effects of psilocybin.

What do you think about this?
 

Quelle: Shao, Ling-Xiao, et al. "Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo." bioRxiv (2021).