Protocol for two models of behavioral transition from action to no-action when facing prolonged uncontrollable experience in mice.

Uncontrollability could lead to behavioral adjustment or even giving up when facing repeated failure. Here, we detail a protocol to study the behavioral transition from action to no-action induced by prolonged uncontrollable experiences in mice. We describe the behavioral devices, video analysis, and the exponential learning curve fitting for mathematical assessment. We perform further validation experiments evaluating locomotor, social, and anxiety-/depression-like behaviors. This approach helps study neural mechanisms underlying adaptive decision-making when facing repeated failure. For complete details on the use and execution of this protocol, please refer to Li et al.1.

A neural circuit for regulating a behavioral switch in response to prolonged uncontrollability in mice.

Persistence in the face of failure helps to overcome challenges. But the ability to adjust behavior or even give up when the task is uncontrollable has advantages. How the mammalian brain switches behavior when facing uncontrollability remains an open question. We generated two mouse models of behavioral transition from action to no-action during exposure to a prolonged experience with an uncontrollable outcome. The transition was not caused by pain desensitization or muscle fatigue and was not a depression-/learned-helplessness-like behavior. Noradrenergic neurons projecting to GABAergic neurons within the orbitofrontal cortex (OFC) are key regulators of this behavior. Fiber photometry, microdialysis, mini-two-photon microscopy, and tetrode/optrode in vivo recording in freely behaving mice revealed that the reduction of norepinephrine and downregulation of alpha 1 receptor in the OFC reduced the number and activity of GABAergic neurons necessary for driving action behavior resulting in behavioral transition. These findings define a circuit governing behavioral switch in response to prolonged uncontrollability.

[Estimated cosmic radiation doses for flight personnel].

Objective. To calculate individual annual cosmic radiation effective dose for monitored flight personnel. Method. With the help of aircraft flight information from flight performance manual, software CARI-6 developed by U.S. Federal Aviation Administration was used to calculate the effective dose of galactic cosmic radiation along the air lines, and to calculate the effective dose rate on the ground in Urumuqi, then individual annual cosmic radiation dose on flight personnel was estimated from the data calculated by CARI-6. Result. The annual cosmic radiation dose on the ground at Urumuqi was 0.420 mSv a-1. The average effective dose rate of all flights of Xinjiang Airlines from 1997 to 1999 was 2.381 microSv h -1(0.33-3. 64 microSv h-1). Average annual cosmic radiation dose on flight personnel was 2.193 mSv a-1 (0.887-4.419 mSv a-1). Conclusion. Annual individual doses of all monitored flight personnel are well below the limit 20 mSv a-1 recommended by International Commission on Radiological Protection (ICRP).