Dr. David Anderson

And she found remarkably

that when mice are socially isolated for two weeks, there is this massive upregulation of tachykinin-2 in their brain.

In fact, if you tag the peptide with a green fluorescent protein from a jellyfish genetically, the brain looks green when the mice are socially isolated because there's so much of this stuff released.

and she went on to show that that increase in tachykinin is responsible for the effect of social isolation to increase aggressiveness and to increase fear and to increase anxiety and in fact there are drugs that block the receptor for tachykinin which were tested in humans

and abandoned because they had no efficacy in the tests that they were analyzed for.

If you give those drugs to a socially isolated mouse, it blocks all of the effects of social isolation.

It blocks the aggression, it blocks the increased fear and the increased anxiety.

And that Moriel described it, the mice just look chill.

It's not a sedative, which is really important.

It's not that the mice are going to sleep.

Most remarkably is once you socially isolate a mouse and it becomes aggressive, you can never put it back in its cage with its brothers from its litter because it will kill them all overnight.

But if you give it this drug, which is called osonotan, that blocks tachykinin-2,

that mouse can be returned to the cage with its brothers and will not attack them and seems to be happy about that for the rest of the time.

So this is an incredibly powerful effect of this drug.

And I've been really interested in trying to get pharmaceutical companies to test this drug, which has a really good safety profile

in humans, in testing it in people who are subjected to social isolation stress or bereavement stress, but it's just very difficult for economic reasons to find a way to get somebody to test that.

This goes back to something called the somatic marker hypothesis that was proposed by Antonio Damasio, who is a neurologist at USC.

The idea that our subjective feeling of a particular emotion

is in part associated with a sensation of something happening in a particular part of our body, the gut, the heart.

If there is a physiology underlying these heat maps, it could reflect increased blood flow to these different structures.