There is a common method to induce schizophrenia-like symptoms in mice that is often used in research. The method involves dosing the mice with a molecule called phenylcyclidine (PCP), better known as the drug angel dust. There are neurological reasons why this drug should cause schizophrenia-like symptoms in mice, and one consequence of its administration is memory loss. Researchers from Denmark recently tested if this memory loss was connected to the microbiome and published their results in Physiology and Behavior.

The researchers devised an experiment where groups of mice were either given PCP or a control. All the mice had their microbiomes tested and underwent a memory test. The scientists discovered that the PCP did heavily change the microbiome, with many genera increasing in abundance, like Roseburia, Dorea, and Odoribacter. In addition, the memory performance also seemed to correlate with the microbiome. As the microbiome rebounded after a 3 week time frame, so did the memory of the mice, even though some other symptoms of the PCP persisted. Finally, the researchers gave some of the mice that were given PCP antibiotics so as to decrease the population of the microbiome. The antibiotics were effective in restoring the memory of the mice even within 3 weeks, suggesting a microbiome connection.

The researchers hypothesize that stress caused from taking PCP may be the root cause of the microbiome shifts and memory loss. Interestingly, some of the bacteria that they identified in the PCP microbiomes had been associated with stress in previous studies. Here at the AMI we don’t like to preach to our readers, but if any of you use PCP and have a big exam coming up, you may want to consider stopping, or at least taking a probiotic.