PT  - JOURNAL ARTICLE
AU  - Quentin Montardy
AU  - Zheng Zhou
AU  - Xuemei Liu
AU  - Zhuogui Lei
AU  - Pengyu Zeng
AU  - Chen Chen
AU  - Yuanming Liu
AU  - Kang Huang
AU  - Mengxia Wei
AU  - Liping Wang
TI  - Glutamatergic and GABAergic neuronal populations in the dorsolateral Periacqueductual Gray have different functional roles in fear conditioning
AID  - 10.1101/781187
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 781187
4099  - http://biorxiv.org/content/early/2019/09/27/781187.short
4100  - http://biorxiv.org/content/early/2019/09/27/781187.full
AB  - It is though that only a subset of brain structures can encode emotional states. This can be investigated though a set of properties, including the ability of neurons to respond to a conditioned stimulus (CS) preceding an aversive unconditioned stimulus (US). The dorsolateral periacqueductal gray (dPAG) is a midbrain structure though to have an essential role in coordinating defensive behaviors in response to aversive stimulation. But its ability of dPAG neurons to encode a CS following fear conditioning as not been sufficiently studied.Here we used calcium imaging by fiber photometry to record the activity of dPAGVGluT2+ and dPAGGAD2+ neuronal populations during unconditioned and conditioned aversive stimulation. Then, following an unconditioned stimulation we performed a retrieval experiment to quantify memory-like responses of dPAG neurons. This shown that whilst both dPAGVGluT2+ and dPAGGAD2+ neuronal populations respond to direct US stimulation, and to CS stimulation during conditioning, only the dPAGVGluT2+ population persisted in responding to the CS stimulation during retrieval. Finally, to better understand dPAGVGluT2+ and dPAGGAD2+ connectivity patterns, we performed a cell specific monosynaptic retrograde rabies virus tracing experiment. This revealed that different patterns of fibers projects to dPAGVGluT2+ and dPAGGAD2+, further complementing our recording showing divergences between PAGVGluT2+ and dPAGGAD2+ populations.