title: Periaqueductal Gray Neuronal Activities Underlie Different Aspects of Defensive Behaviors.
abstract: Defense is a basic survival mechanism when animals face danger. Previous studies have suggested that the midbrain periaqueductal gray (PAG) is essential for the generation of defensive reactions. Here we showed that optogenetic activation of neurons in the PAG in mice was sufficient to induce a series of defensive responses (including running, freezing, and avoidance). However, the endogenous neural dynamics of the PAG underlying defensive behaviors still remain elusive. Using chronic extracellular recording, we recorded the spiking activities of PAG neurons in freely behaving mice exposed to natural threats (rats). We observed that there exist distinct neuronal subsets within the PAG participating in respective detection (risk assessment) and response (flight) aspects of defensive behaviors. Our results demonstrate the important role of PAG neuronal activities in the control of different aspects of defensive behaviors, and provide novel insights for investigating defense from an electrophysiological perspective.
  
  
  
  Defense is crucial for animals' survival in nature. Here, using optogenetic stimulation and in vivo recording in behaving mice reacting to threats, we explored the role of the midbrain periaqueductal gray (PAG) in defense. We show that optogenetic activation of PAG neurons is sufficient to elicit different aspects of defensive responses. Consistently, the present study provides in vivo evidence demonstrating that activity of the population of dorsal PAG neurons is activated during defense. Also, different subpopulations of units recorded in the dorsal PAG participate in distinct aspects of defensive behaviors. These findings help us understand the role of the PAG in animal behavior at the single neuron level.
authors.affiliation: Institute of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and Graduate School of University of Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Hanfei
authors.identifier: 0000-0002-5034-9935
authors.initials: H
authors.lastname: Deng
authors.affiliation: Institute of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and Graduate School of University of Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Institute of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and zuorenwang@ion.ac.cn.
authors.forename: Zuoren
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003213:Conditioning, Psychological; D003674:Defense Mechanisms; D005239:Fear; D005786:Gene Expression Regulation; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics; D018408:Patch-Clamp Techniques; D010487:Periaqueductal Gray / Q000166:cytology*; D051381:Rats; D020318:Rats, Long-Evans; D012243:Rhodopsin / Q000235:genetics / Q000378:metabolism; D014005:Tinea; D014161:Transduction, Genetic
chemical_list: D002135:Calcium-Binding Proteins; C581829:Camk2n1 protein, rat; D002352:Carrier Proteins; D008164:Luminescent Proteins; D012243:Rhodopsin
keywords: defensive behavior; electrophysiology; innate behavior; optogenetics; periaqueductal gray