Dopaminergic regulation of fear extinction learning

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04264
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Neurophysiology / General neuroscience
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Johansen Joshua 国立研究開発法人理化学研究所, 脳科学総合研究センター, チームリーダー (80625351)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: Dopamine / Extinction / Fear

Outline of Final Research Achievements

We examined the contribution of the ventral tegmental area (VTA) dopamine system to fear extinction learning. During fear conditioning, animals learn that an auditory tone stimulus predicts the occurrence of an aversive event (shock) and animals exhibit fear behaviors to the tone following learning. If the tone is presented repeatedly in the absence of the aversive event fear responses are reduced through extinction. We found that optogenetic inhibition of VTA-dopamine neurons during the shock omission period of extinction blocked extinction learning as well as biochemical signatures of neural plasticity in the extinction learning system. Furthermore, we discovered that a specific population of dopamine neurons projecting to the nucleus accumbens were responsible for this effect. These results reveal an unappreciated role for the dopamine reward system in extinguishing fear memories and suggest novel treatment avenues for fear related psychiatric disorders.

Free Research Field

Neuroscience