Brain Escape Switch !

This is just a short post to update you on groundbreaking science that shows great promise.

This research published only two days ago and undertaken by the Sainsbury Welcome Centre part of the University College London involves a study currently on mice that may have implications for people like myself who suffer with anxiety and those with PTSD .

Researchers and Neuroscientists think that they have located the bidirectional switch or at least the neuron’s that turn on and off , in effect regulates the threat response and controls the escape response in mice .

Scientists looked at the area of the brain that is known to be hyper sensitive in anxiety and trauma sufferers called the periaqueductal gray (PAG). This a brain region that plays a critical role in autonomic  function, motivated behaviour and behavioural responses to threatening stimuli.(It has enkephalin -producing cells that suppress pain, as well as the learning and action of defensive and aversive behaviours).

Scientists have discovered that this area is constantly firing , they further discovered that they might be able to dial up or down these firing neuron’s.

The mice used in this research seemed to link their escape behaviour to past experience. Escape behaviour state the researchers , is not constant it can be adapted , its not fixed. Also they noted that experience reflected on how long the escape behaviour lasted for. This could have implications for those with anxiety or PTSD noted Professor Tiago Branco the lead Scientist in the study .

The initial work was done in a dish ( in vitro ) and looked at how escape behaviour is controlled by the brain . They noticed that the PAG inhibitory neuron’s always fired when not receiving any other external input. This area is also directly connected to the excitatory neuron’s ,…… these play a very important part of the escape process.

If you can imagine that the body is primed for escape , there are inhibitory neuron’s that down regulate this escape network . However just before the mice tried to escape a group of cells were found to express lower activity thus allowing the inhibition to be removed and the escape initiated . Its a bit like a racing dog in a cage before a race , the dog is primed and ready to go but the gate of the cage is close the dog can see the bait being dragged down the track , but it can do nothing as the gate is closed . Suddenly the gate retracts and the dog shoots off .

Another group of cells then come into play , slowly increasing they let the mice know when to stop , they let the mice know they have reached safety , the dog is put back in the cage with a bone and a pat.

Further study using light to control the activity of the neuron’s ( optogenetics ) manipulated these neuron’s to excite or inhibit ( turn up or down) .When they turned up the PAG inhibitory neuron the likelihood of escape behaviour decreased , this also worked in reverse causing the chances of escape to increase. This confirmed that the PAG could be dialled up or down.

Researcher’s also noted that they could change when the mice felt safe , they managed to keep the escape response going even after a place of safety and made the mice feel safe when they had not escaped.

I had to write this up , even though research on this was only published a few days ago at the time of this post . It’s really exciting news for us anxiety sufferers. If a molecular pathway is discovered that would allow drugs to be used to turn up or down this fear response that would be game changing for anxiety and PTSD sufferers.

Just to go over that point one more time …scientist think they have found the area that switches our escape to safety response on and off !

I encourage you to read the research at in Current Biology: ‘Tonically active GABAergic neurons in the dorsal periaqueductal gray control instinctive escape in mice’ DOI: 10.1016/j.cub.2024.05.068