Loneliness affects both mental and physical health, but counter intuitively it can also result in a decreased desire for social interaction
In order to take a closer look at the mechanics of this contradiction, and for the purpose of analyzing social behavior during lock down, scientists at both the Sainsbury Wellcome Centre, and the Wolfson Institute, put a spotlight on zebrafish.
For several gruesome months, a large percentage of us have been undergoing the impact of social isolation. At least 50% of the world’s inhabitants have been affected by some type of lock down measures due to COVID-19.
A detailed view of the zebrafish brain can provide important clues for all of us currently experiencing the effects of social isolation.
The scientists’ findings were published in the journal, eLife. These showed that “most zebrafish demonstrate pro-social behaviour, but approximately 10% are ‘loner’ fish who are averse to social cues and demonstrate different brain activity than their pro-social siblings. However, even typically social zebrafish avoid social interaction after a period of isolation.”
Welcome Fellow Elena Dreosti, Postdoctoral Research Fellow Thomas Ryan; Dr Adam Kampff and Sir Henry Dale, along with the help of two PhD students, set about on a mission to determine “whether the brain activity of isolated zebrafish mimics that of loner fish or whether other forces were at play.”
Investigating the Effects of Isolation
The scientists’ game plan involved a two-day process of isolating typically social zebrafish from the other fish. During this period of time, the researchers looked at the brain activity of the other fish and made a comparison with that of the zebrafish. The zebrafish showed a dislike for social interaction without being isolated. “The isolated fish demonstrated sensitivity to stimuli and had increased activity in brain regions related to stress and anxiety. [However], these effects of isolation were quickly overcome when the fish received a drug that reduces anxiety.”
Interestingly, the region of the brain responsible for social rewards (the hypothalamus), showed the main differences between the loner fish and their siblings. In fact, during social exposure, the hypothalamus of the loner fish, did not show the same activation pattern as its regular counterparts, thus implying that at times of social interaction, loner fish do not sense rewards in the same manner as typical fish.
Conversely, the fish which were lonely, and showed normal social behaviour while kept in isolation demonstrated hypersensitivity to stimuli and activation of brain regions associated with stress and anxiety. Lonely fish experienced actively negative outcomes from social interaction whereas loner fish simply did not experience reward.
The End of Lock down
While we will not all emerge from lock down as loners, some people will be anxious about their normal social lives. To that end, when life finally comes back to normal, we need to be mindful of this new anxiety and sensitivity, while at the same time, be determined to reclaim our healthy, normal, fun social existence.