Graduate Student, National Centre for Biological Sciences


Stress has debilitating effects on the physiology on an animal – often leading to conditions like Post-Traumatic Disorder (PTSD), where exposure to a single episode of severe stress or trauma leads to delayed symptoms including increase in anxiety and hyper-function of the amygdala. In a pre-clinical translational model of PTSD, a single, acute episode of stress in male rats causes a like-wise increase in anxiety and dendritic spines in the amygdala, 10 days after stress but not 1 day later. This suggests that the effects develop over time, hence prompting the question if the delayed effects in this model could be prevented by intervening after exposure to acute stress. We found that a single-dose intervention with a classical anxiolytic after stress prevented both behavioural and cellular changes from happening 10 days later. In addition, when acute stress was followed by another brief stress-exposure immediately afterwards, it showed similar preventive effects as well. The mechanism of these dual modes of prevention are currently being examined to better understand the possible approaches that could eventually translate to therapeutic intervention strategies.


Using Neuroscience to Help Understand Fear and Anxiety: A Two-System Framework.

Abstract: Tremendous progress has been made in basic neuroscience in recent decades. One area that has been especially successful is research on how the brain detects and responds to threats. Such studies have demonstrated comparable patterns of brain-behavior relationships underlying threat processing across a range of mammalian species, including humans. This would seem to be an ideal body of information for advancing our understanding of disorders in which altered threat processing is a key factor, namely, fear and anxiety disorders. But research on threat processing has not led to significant improvements in clinical practice. The authors propose that in order to take advantage of this progress for clinical gain, a conceptual reframing is needed. Key to this conceptual change is recognition of a distinction between circuits underlying two classes of responses elicited by threats: 1) behavioral responses and accompanying physiological changes in the brain and body and 2) conscious feeling states reflected in self-reports of fear and anxiety. This distinction leads to a "two systems" view of fear and anxiety. The authors argue that failure to recognize and consistently emphasize this distinction has impeded progress in understanding fear and anxiety disorders and hindered attempts to develop more effective pharmaceutical and psychological treatments. The two-system view suggests a new way forward.

Pub.: 10 Sep '16, Pinned: 23 Jun '17