Instinctive behaviorsare vital to the survival oforganisms, includingfeeding, mating, fighting and hunting.Those behaviorsare considered to be stereotypedevolutionarily, which respond quickly to external stimuli and ensure rapid and stable responses to instinctive behaviors.However, instinctive behaviors also need to be adjusted in real time according to the environment to ensure the flexibility of behaviors when the animal to deal with complex environmental stimuli.On November 11, 2021, Nature Communications published online the research results of the collaboration between Professor Haohong Li and Professor Wei Shen (Shanghai University of Science and Technology)："Periaqueductal Gray Neurons Encode the Sequential Motor Program in Hunting Behavior of Mice".The research team elucidatesthelateral periaqueductal gray (LPAG) neurons encode the basic rules of hunting in animals, and propose the concept of encoding sequentially of instinctive behavior in mammals for the first time.
Sequential encoding of motor programs is essential for behavior generation.The sequential neuronal activity has been established in the hippocampus and motor cortex during memory or decision-makingtasks, which is essential for navigation planning and motor generation. However, the neural substrate underlying instinctive behavioral sequences such as that in hunting is still mostly unknown. In this study,in vivosingle-unit recordings, optrode recordings and photogenetic manipulation are used to elucidate the neural mechanism.In vivosingle-unit recordings indicate that LPAGneuron ensembles displaye a sequential activity pattern to the preytarget, and the activity is time-locked to different hunting actions. Optroderecordings and photoinhibition demonstrate that LPAGVgatneurons are required for the preydetection, chase and attack, while LPAGVglut2neurons are selectively required for the attack. Together, LPAG neurons form multiple clusters that control hunting actions and encode different hunting phases respectively. These hunting command modules can form more advanced sequence instructions to guide the action sequence of hunting.
Scheme of LPAG encodingthe sequential motor program in hunting
The LPAG receives GABAergic inputsfrom key brain regions involved in hunting, including thecentral amygdala(CeA),thelateral hypothalamus (LH), and theZonaincerta(ZI). How these inputs affect the formation of thedynamic predatory sequence in the LPAG is largely unknown. Totest the effect of distinct inputs on the hunting sequence, the studyperformedin vivosingle-unit recordings on LPAG neurons after input-specific lesions during predatory hunting. Lesions of LPAG afferents differentially affect LPAG neuronal activityin predatory phases and destroy thesequential activity pattern intact, which affected the hunting behavior. In summary, the study reveals the mechanism by which LPAGneuronalensembles encode hunting action sequences. This encoding method not only ensures the accuracy and stability of the action output, but also ensures the flexibility of the animal to deal with the changes of the external environment, thus improving the success rate of animal hunting. Meanwhile, it might provide aframework for decoding complex instinctive behaviors, such as feeding, mating, fighting and hunting.
Dr. Hong Yu, Dr. Xinkuan Xiang and Dr. Zongming Chen are the co-first authors of this paper, and Professor Haohong Li thelastcorresponding author.The first unit is Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology. This study was supported by National Key Research and Development Program of China (2019YFA0801900), the Innovation Fund of Wuhan National Laboratory of Optoelectronics (WNLO), National Natural Science Foundation of China (31671105; 91857104 and 31771169), Science Fund for Creative Research Group of China (61721092), CAMS Innovation Fund for Medical Sciences (2019-I2M-5-057), Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions (NYKFKT20190017).
Link to the paper: https://www.nature.com/articles/s41467-021-26852-1
