| Autor: |
Johnson SB; Interdisciplinary Neuroscience Program, The University of Iowa, Iowa City, IA 52242., Lingg RT; Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA 52242., Skog TD; Interdisciplinary Neuroscience Program, The University of Iowa, Iowa City, IA 52242., Hinz DC; Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA 52242., Romig-Martin SA; Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA 52242., Viau V; Department of Cellular and Physiological Sciences, The University of British Columbia, Vancouver, BC V6T 1Z2, Canada., Narayanan NS; Interdisciplinary Neuroscience Program, The University of Iowa, Iowa City, IA 52242.; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242.; Department of Neurology, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242., Radley JJ; Interdisciplinary Neuroscience Program, The University of Iowa, Iowa City, IA 52242.; Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA 52242.; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242. |
| Abstrakt: |
The question of how the brain links behavioral and biological features of defensive responses has remained elusive. The importance of this problem is underscored by the observation that behavioral passivity in stress coping is associated with elevations in glucocorticoid hormones, and each may carry risks for susceptibility to a host of stress-related diseases. Past work implicates the medial prefrontal cortex (mPFC) in the top-down regulation of stress-related behaviors; however, it is unknown whether such changes have the capacity to buffer against the longer-lasting biological consequences associated with aversive experiences. Using the shock probe defensive burying test in rats to naturalistically measure behavioral and endocrine features of coping, we observed that the active behavioral component of stress coping is associated with increases in activity along a circuit involving the caudal mPFC and midbrain dorsolateral periaqueductal gray (PAG). Optogenetic manipulations of the caudal mPFC-to-dorsolateral PAG pathway bidirectionally modulated active (escape and defensive burying) behaviors, distinct from a rostral mPFC-ventrolateral PAG circuit that instead limited passive (immobility) behavior. Strikingly, under conditions that biased rats toward a passive coping response set, including exaggerated stress hormonal output and increased immobility, excitation of the caudal mPFC-dorsolateral PAG projection significantly attenuated each of these features. These results lend insight into how the brain coordinates response features to overcome passive coping and may be of importance for understanding how activated neural systems promote stress resilience. |
