Nav: Home

Scientists identify a novel neural circuit mediating visually evoked innate defensive responses

June 12, 2019

Fear overgeneralization (i.e., deficits in the discrimination of safety and threat) is an important pathological characteristic of anxiety-related syndromes such as posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD) and panic disorder.

However, unlike traditional conditioned fear, the mechanism of processing innate fear is largely unknown.

Prof. WANG Liping and his colleagues ZHOU Zheng and LIU Xuemei at the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences revealed that the VTA (ventral tegmental area) GABAergic neural circuit mediates visually evoked innate defensive responses.

In this study, the research group identified for the first time a neural circuit related to the VTAGABA+ neurons that mediates visually evoked innate defensive responses, involving the SC Glut+_ VTAGABA+_ CeA (central nucleus of the amygdala) pathway.

It has been confirmed by neuroscientists that the VTA plays an important role in learned appetitive and aversive behaviors. Interestingly, the researchers revealed that the GABA neurons in VTA were activated by visual threats by fiber photometry. Through viral tracing and both in vivo and in vitro electrophysiological recordings, they showed that VTAGABA+ neurons received direct excitatory inputs from the superior colliculus (SC).

The researchers revealed that VTAGABA+ neurons mediated looming-evoked innate defensive behaviors. These findings demonstrated that SC glutamatergic inputs activated VTAGABA+ neurons and mediated looming-evoked innate defensive behaviors. They further showed that CeA was a downstream target of the SC-VTA GABAergic pathway and it was involved in innate defensive behavior.

This study provides new insights into potential mechanisms of survival across species, as well as the maladaptive behavior in fear- and anxiety-related mental disorders.

The team has been working on the dissection of the neural circuits mediating instinctive emotions for years. In their previous work, they have resolved a novel brain circuit controlling visually evoked innate freezing behaviors via the SC-LP-LA subcortical pathway. They also had pioneering work which first reported that the accelerated innate defensive response to visual threats induced by stress is mediated by the Locus Coeruleus (LC) directed TH+ projections to the SC. The current study published in Neuron is another key milestone in their systematic work.
-end-


Chinese Academy of Sciences Headquarters

Related Fear Articles:

Fear of hospitalization keeps men from talking about suicide
Fear of psychiatric hospitalization is one of the primary reasons that older men -- an age and gender group at high risk for suicide -- don't talk about suicide with their physicians.
Brain activity predicts fear of pain
Researchers applied a machine learning technique that could potentially translate patterns of activity in fear-processing brain regions into scores on questionnaires used to assess a patient's fear of pain.
How to trigger innate fear response?
There are two types of fear: learned versus innate. The latter is known to be induced without any prior experience and is thus naturally encoded in the brain.
Yellowstone's 'landscape of fear' not so scary after all
After wolves were reintroduced to Yellowstone National Park in the mid-1990s, some scientists thought the large predator reestablished a 'landscape of fear' that caused elk, the wolf's main prey, to avoid risky places where wolves killed them.
Stress helps unlearn fear
Stress can have a positive effect on extinction learning, which causes previously learned associations to dissolve.
More Fear News and Fear Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...