ABSTRACT
The regulation of fear memories is critical for adaptive behaviors and dysregulation of these processes is implicated in trauma- and stress-related disorders. Treatments for these disorders include pharmacological interventions as well as exposure-based therapies, which rely upon extinction learning. Considerable attention has been directed toward elucidating the neural mechanisms underlying fear and extinction learning. In this review, we will discuss historic discoveries and emerging evidence on the neural mechanisms of the adaptive regulation of fear and extinction memories. We will focus on neural circuits regulating the acquisition and extinction of Pavlovian fear conditioning in rodent models, particularly the role of the medial prefrontal cortex and hippocampus in the contextual control of extinguished fear memories. We will also consider new work revealing an important role for the thalamic nucleus reuniens in the modulation of prefrontal-hippocampal interactions in extinction learning and memory. Finally, we will explore the effects of stress on this circuit and the clinical implications of these findings.
ABSTRACT
Traumatic events result in vivid and enduring fear memories. Suppressing the retrieval of these memories is central to behavioral therapies for pathological fear. The medial prefrontal cortex (mPFC) and hippocampus (HPC) have been implicated in retrieval suppression, but how mPFC-HPC activity is coordinated during extinction retrieval is unclear. Here we show that after extinction training, coherent theta oscillations (6-9 Hz) in the HPC and mPFC are correlated with the suppression of conditioned freezing in male and female rats. Inactivation of the nucleus reuniens (RE), a thalamic hub interconnecting the mPFC and HPC, reduces extinction-related Fos expression in both the mPFC and HPC, dampens mPFC-HPC theta coherence, and impairs extinction retrieval. Conversely, theta-paced optogenetic stimulation of RE augments fear suppression and reduces relapse of extinguished fear. Collectively, these results demonstrate a role for RE in coordinating mPFC-HPC interactions to suppress fear memories after extinction.
Subject(s)
Fear , Midline Thalamic Nuclei , Rats , Male , Female , Animals , Midline Thalamic Nuclei/physiology , Rats, Long-Evans , Fear/physiology , Prefrontal Cortex/physiology , Hippocampus/physiology , Extinction, Psychological/physiologyABSTRACT
The current semi-experimental pilot study was conducted to investigate the effects of dance and movement therapy methods (DMTM) on compassion satisfaction, burnout, and compassion fatigue in nurses using a pre-/posttest design. Nurses (N = 8) with low compassion satisfaction, high burnout, and high compassion fatigue participated in eight sessions of DMTM. Upon completion of the program, average compassion satisfaction levels increased, and burnout and compassion fatigue levels decreased. Although further testing with larger samples is necessary, preliminary results indicate DMTM is effective for addressing compassion satisfaction, burnout, and compassion fatigue in nurses. [Journal of Psychosocial Nursing and Mental Health Services, 58(4), 43-51.].
