Research Hit: Stress Changes Brain's Sound Responses
New research shows that chronic stress changes brain responses to low level sounds
Isn’t stress a whole brain response?
Well, yes, kind of. That it alters multiple pathways is well-known and researched. But all brain responses change multiple pathways and understanding these, what precisely and how they are triggered is important. And this research adds another little twist to the stress brain response.
Also of note is that this is in chronic stress situations not acute short-term stress.
So, what changed to sound?
Dr. Jennifer Resnik from Ben-Gurion of the Negev has been researching whether stress impacts basic brain functions apart from the obvious emotional responses that have been well documented.
With a team around Ghattas Bisharat, lead author, they observed brain responses in chronically stressed mice to simple sounds.
They found that the brain’s responses to low level sounds was much reduced but it kept its sensitivity to loud sounds.
Oh, that is interesting and explains a lot.
Yes, it can shift everyday perception of “normal” sounds to only responding to excessive sounds. If we translated this to other senses (which might be a leap of imagination), it suggests lower responses to everyday normal stimuli and only sensitivity to high stimuli.
That could be quite dramatic!
Yes, because this responsivity pattern could also lead to a negative loop and continued stress.
And what was happening in the brain?
This is interesting because the researchers managed to find the precise group of cells that were changing this response.
They found that a group of cells called SST cells became hyperactive. This type of brain cell in the cortex responds and releases certain neurotransmitters that are involved in suppressing responses - here they are suppressing responses to low auditory input.
So SST cells are changing the brain’s responses
Yes, to low level sounds - high levels sounds trigger a normal response.
So the brains of people with chronic stress may be less responsive to low level stimuli and only respond to high level stimuli - which in turn could also impact stress?
Well, this research was only in mice. Further research will confirm whether this is the same in human beings. But it does seem to match our observational impacts of those in chronic stress. As I said we already know that stress changes emotionality and decision-making ability.
Reference
Bisharat G, Kaganovski E, Sapir H, Temnogorod A, Levy T, Resnik J (2025)
Repeated stress gradually impairs auditory processing and perception.
PLoS Biol 23(2): e3003012.
https://doi.org/10.1371/journal.pbio.3003012