Article
Multidisciplinary Sciences
Ricardo P. Bindi, Cibele C. Guimaraes, Amanda R. de Oliveira, Fernando F. Melleu, Miguel A. X. de Lima, Marcus V. C. Baldo, Simone C. Motta, Newton S. Canteras
Summary: The present study systematically analyzed the afferent and efferent projections of the CUN and investigated its role in fear responses. The CUN was found to be a caudal component of the periaqueductal gray and had strong links with the dorsolateral periaqueductal gray. It was also found to mediate innate antipredatory responses but not learned fear responses.
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
(2023)
Article
Neurosciences
Fernando M. C. V. Reis, Dean Mobbs, Newton S. Canteras, Avishek Adhikari
Summary: This article discusses the central role of the midbrain periaqueductal gray (PAG) in controlling various defensive responses and explores how PAG-centered circuits influence both innate and learned defensive actions in rodents and humans. It highlights the use of traditional methods like lesions, electrical stimulation, and pharmacology, as well as recent advancements in neural activity imaging and anatomical and genetic control methods to gain a better understanding of PAG function.
Article
Acoustics
Yibo Wang, Lili Niu, Wen Meng, Zhengrong Lin, Junjie Zou, Tianyuan Bian, Xiaowei Huang, Hui Zhou, Long Meng, Ping Xie, Hairong Zheng
Summary: This study demonstrated that LIFUS stimulation of the PAG induced defensive behaviors in mice, without causing any injury to the brain tissue. LIFUS may be a novel neuromodulatory tool for treating psychological diseases associated with defensive behaviors.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2021)
Article
Biology
Weisheng Wang, Peter J. Schuette, Mimi Q. La-Vu, Anita Torossian, Brooke C. Tobias, Marta Ceko, Philip A. Kragel, Fernando M. C. Reis, Shiyu Ji, Megha Sehgal, Sandra Maesta-Pereira, Meghmik Chakerian, Alcino J. Silva, Newton S. Canteras, Tor Wager, Jonathan C. Kao, Avishek Adhikari
Summary: The study showed that PMd-cck cells in mice are activated during escape, and inhibition of the PMd decreases escape speed. The PMd-dlPAG circuit is identified as a central node controlling escape behavior in response to threats.
Review
Cell Biology
Priscila Vazquez-Leon, Abraham Miranda-Paez, Kenji Valencia-Flores, Hugo Sanchez-Castillo
Summary: Serotonin is a crucial neurotransmitter that regulates various physiological processes and psychiatric disorders. The periaqueductal gray matter is an important center for defensive behaviors, and electrical stimulation in this region can induce panic, fight-flight, and freezing responses. Serotonergic activity in the periaqueductal gray matter is influenced by other brain areas and the activation of specific receptors, promoting serotonin release. This review emphasizes the role of 5-HT1A and 5-HT2A/C receptors in anxiety, panic, fear, analgesia, and aggression, suggesting their potential for the treatment of mental disorders.
CELLULAR AND MOLECULAR NEUROBIOLOGY
(2023)
Article
Neurosciences
Jeremy Signoret-Genest, Nina Schukraft, Sara L. Reis, Dennis Segebarth, Karl Deisseroth, Philip Tovote
Summary: In this study, the researchers identify rapid microstates that are associated with specific behaviors and heart rate dynamics. These microstates are affected by long-lasting macrostates and reflect context-dependent threat levels. The study also demonstrates that freezing behavior, as a defensive response, is part of an integrated cardio-behavioral microstate mediated by Chx10(+) neurons in the periaqueductal gray. The framework presented in this study allows for a better understanding of complex neural defensive states and their associated functions.
NATURE NEUROSCIENCE
(2023)
Review
Neurosciences
Justin M. Moscarello, Mario A. Penzo
Summary: The article proposes that mutually inhibitory circuits within the central nucleus of the amygdala implement a 'winner-takes-all' mechanism that guides transitions across defensive modes defined by threat-imminence theory.
NATURE NEUROSCIENCE
(2022)
Article
Biology
Mimi Q. La-Vu, Ekayana Sethi, Sandra Maesta-Pereira, Peter J. Schuette, Brooke C. Tobias, Fernando M. C. Reis, Weisheng Wang, Anita Torossian, Amy Bishop, Saskia J. Leonard, Lilly Lin, Catherine M. Cahill, Avishek Adhikari
Summary: This study reveals the role of specific cells in the midbrain periaqueductal gray in regulating defensive behaviors. Activation or inhibition of certain cells can induce either flight or freezing responses, respectively. The activity of these cells is associated with the distance and location of the threat.
Article
Multidisciplinary Sciences
Julia Ruat, Andreas J. Genewsky, Daniel E. Heinz, Sebastian F. Kaltwasser, Newton S. Canteras, Michael Czisch, Alon Chen, Carsten T. Wotjak
Summary: A study found that mice with high anxiety-related behavior emit audible calls, which are sensitive to anxiolytics and controlled by the activity of the periaqueductal gray. These calls can attract both predators and conspecifics, depending on the context.
Article
Neurosciences
Fernando M. C. V. Reis, Jinhan Liu, Peter J. Schuette, Johannes Y. Lee, Sandra Maesta-Pereira, Meghmik Chakerian, Weisheng Wang, Newton S. Canteras, Jonathan C. Kao, Avishek Adhikari
Summary: The study reveals that the dorsal periaqueductal gray (dPAG) uses shared patterns of activity to encode distance and predict defensive behaviors when encountering threats, indicating its crucial role in defensive responses.
JOURNAL OF NEUROSCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Yang Bai, Bryce Grier, Erez Geron
Summary: By studying fear learning in mice, researchers discovered that negative tone responses in the primary motor cortex (M1) are developed after conditioning, depending on the weakening of active dendritic spines during training. Blocking this form of anti-Hebbian plasticity disrupts negative tone responses and freezing. Therefore, reducing the strength of active dendritic spines during memory encoding leads to negative responses in M1, aiding freezing.
Article
Multidisciplinary Sciences
Chen Li, Norma K. Kuhn, Ilayda Alkislar, Arnau Sans-Dublanc, Firdaouss Zemmouri, Soraya Paesmans, Alex Calzoni, Frederique Ooms, Katja Reinhard, Karl Farrow
Summary: Behavioral flexibility relies on the directed routing of sensory information. In the superior colliculus, inhibitory projection neurons projecting to different targets modulate responses to visual threats. By tracing neural connections and conducting recordings, it was found that these inhibitory neurons form separate populations projecting to the lateral geniculate nucleus (LGN) and the parabigeminal nucleus (PBG), receiving different inputs. Inhibiting LGN-projecting Gad2 neurons increased freezing behavior, while inhibiting PBG-projecting Gad2 neurons increased escaping behavior, indicating context-specific effects on behavior.
Article
Neurosciences
Li-Feng Yeh, Takaaki Ozawa, Joshua P. Johansen
Summary: The dorsolateral subregion of the PAG (dlPAG) plays a key role in memory formation in response to aversive events, while the ventrolateral PAG (vlPAG) does not have the same effect. In addition, specific populations of thalamus-projecting dlPAG neurons projecting to the anterior paraventricular thalamus (aPVT) can affect aversive learning, but do not impact previously learned defensive behaviors.
Article
Chemistry, Analytical
Botao Lu, Penghui Fan, Yiding Wang, Yuchuan Dai, Jingyu Xie, Gucheng Yang, Fan Mo, Zhaojie Xu, Yilin Song, Juntao Liu, Xinxia Cai
Summary: Defense is the basic survival mechanism of animals when facing dangers. This study found that the neuronal activities of dPAG play a crucial role in controlling different types of predator odor-evoked innate fear/defensive behaviors, with stronger activation during the flight stage. The results provide guidance for predicting defense behavior.
Review
Neurosciences
Yu-Ting Tseng, Bernhard Schaefke, Pengfei Wei, Liping Wang
Summary: Animals need to balance defensive responses against predators with other adaptive behaviors. Accumulating evidence suggests that endocrine, immune, gastrointestinal, and reproductive systems play important roles in modulating behavioral responses to threat. Understanding the interconnected network between the brain and body is crucial for appropriate defensive responses to threats.
NATURE REVIEWS NEUROSCIENCE
(2023)