A study published in Molecular Psychiatry suggests that certain enzymes in the brain may have a previously unrecognized link to how certain animals form friendships. The researchers wanted to test whether or not there is a genetic basis for the tendency of humans to choose relationships based on similarities, called homophily.
To do this, they studied the three regions of the brain most responsible for social interaction: the hippocampus (center for memory), the cerebral cortex (center responsible for consciousness and self-control), and the limbic system (the area of the brain responsible for emotion and motivation). These researchers believe that a link found within the mice subjects can be extrapolated to explain human emotional interaction and connection.
Michy P. Kelly, the study leader, found that an enzyme released in these parts of the brain, PDE11A-cAMP-CREB (shortened to PDE11a) is related to which mice spend time together.
The results of the experiment show how the mice that did not possess any PDE11A would prefer to interact with other mice without the enzyme. Mice with PDE11A prefer to interact with each other as well. Changes made to the concentration of the enzyme by researchers would also affect the mice and their interaction.
