Nat Commun and Xiong Wei's research team analyze the "shocked" neural circuit

EditorEnzyme Beauty We are often "shocked" by sudden sounds and touches around us.
This behavior is called startle reflex
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This is a highly conservative instinctive defensive behavior possessed by mammals.
It occurs before other defensive actions such as freezing, flight, and fighting take place
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A sudden sound or tactile stimulus can quickly induce the startle reflex within a few milliseconds.
The emergence of this reflex can urgently mobilize many reactions of the body, such as muscle contraction, adrenaline soaring, heart rate increase, etc.
, as a follow-up further defense Be prepared for the response
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Abnormal startle reflex behavior is closely related to mental diseases such as Post-traumatic stress disorder (PTSD) and panic disorder (PD)
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Although the importance of the startle reflex is self-evident, the basic neural circuits that control the startle reflex are currently unclear
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On November 04, 2021, Professor Xiong Wei's research group from the Department of Life Sciences and Medicine of the University of Science and Technology of China published a new research result online in Nature Communications, titled A brainstem reticulotegmental neural ensemble drives acoustic startle reflexes
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In this work, the researchers discovered the neural circuit of cochlear nucleus-pontine caudal reticular nucleus-spinal cord motor neuron by means of optogenetic, chemical genetic manipulation, in vivo electrophysiological recording and loop tracing.
It plays an important role in regulating startle reflex behavior
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Researchers first used c-fos staining and in vivo calcium signal recording and found that sound-induced startle reflex (ASR) causes glutamatergic neurons in the pontine caudal nucleus (Reticulotegmental nucleus, RtTg) Activated by a large amount, the calcium signal is significantly enhanced (Figure 1)
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Subsequently, the researchers used optogenetic and chemical genetic methods and found that specific activation of RtTg glutamatergic neurons can induce typical startle reflex behavior in mice, while specific inhibition of RtTg glutamatergic neurons can reduce small The startle reflex of the rat does not affect other behaviors such as motor coordination, gait, and perception
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Figure 1.
When sound stimulation induces startle reflex, glutamatergic neurons in mouse RtTg are activated.
Next, the researchers traced the virus upstream and downstream of the RtTg nucleus and found that RtTg directly received from the cochlear nucleus (Cochlear nucleus, CN), where CN is the first-level receiving nucleus where sound information enters the brain
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Optogenetic/chemical genetic specific activation/inhibition of CN-RtTg projection can induce/inhibit the startle reflex in mice (Figure 2)
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The results of further virus tracking experiments showed that the RtTg neurons that received CN input directly projected to Spinal motor neurons, and finally completed the control of the neck and limb muscles
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Figure 2.
The RtTg nucleus receives direct projections from the CN of the cochlear nucleus.
In summary, this study identified a RtTg-mediated neural circuit that controls the startle reflex (Figure 3).
The results of the study have deepened our instinctive defense behavior.
The understanding of the mechanism also provides a new direction for the follow-up study of abnormal startle reflex behaviors in diseases such as post-traumatic stress disorder and panic disorder
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Figure 3.
Schematic diagram of the neural circuit that controls the startle reflex.
The corresponding author of this paper is Professor Xiong Wei from the Department of Life Sciences and Medicine, University of Science and Technology of China
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Dr.
Weiwei Guo and Dr.
Sijia Fan are the co-first authors of the paper
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This research also received great help from Professor Zhou Yifeng and Professor Xue Tian from the University of Science and Technology of China, and Professor Li Yulong from Peking University
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Original link: http://doi.
org/10.
1038/s41467-021-26723-9 Plate maker: Notes for reprinting on the 11th [Non-original article] The copyright of this article belongs to the author of the article.
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