Serine Racemase and D-serine in the Amygdala Are Dynamically Involved in Fear Learning
| Autor: | Kevin Muszynski, Kerry J. Ressler, Joseph T. Coyle, Kendall Taylor Presti, Inna Radzishevsky, Darrick T. Balu, Cathy C.Y. Huang, Herman Wolosker, Guia Guffanti |
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| Rok vydání: | 2018 |
| Předmět: |
Adult
Male 0301 basic medicine Conditioning Classical Racemases and Epimerases Biology Amygdala Article Extinction Psychological Stress Disorders Post-Traumatic Serine Mice 03 medical and health sciences 0302 clinical medicine medicine Animals Humans Fear conditioning Biological Psychiatry Cellular localization Neurons Fear processing in the brain Fear Extinction (psychology) Immunohistochemistry 030104 developmental biology medicine.anatomical_structure Serine racemase NMDA receptor Neuroscience 030217 neurology & neurosurgery Genome-Wide Association Study |
| Zdroj: | Biological Psychiatry. 83:273-283 |
| ISSN: | 0006-3223 |
| Popis: | Background The amygdala is a central component of the neural circuitry that underlies fear learning. N-methyl-D-aspartate receptor–dependent plasticity in the amygdala is required for pavlovian fear conditioning and extinction. N-methyl-D-aspartate receptor activation requires the binding of a coagonist, D-serine, which is synthesized from L-serine by the neuronal enzyme serine racemase (SR). However, little is known about SR and D-serine function in the amygdala. Methods We used immunohistochemical methods to characterize the cellular localization of SR and D-serine in the mouse and human amygdala. Using biochemical and molecular techniques, we determined whether trace fear conditioning and extinction engages the SR/D-serine system in the brain. D-serine was administered systemically to mice to evaluate its effect on fear extinction. Finally, we investigated whether the functional single nucleotide polymorphism rs4523957, which is an expression quantitative trait locus of the human serine racemase (SRR) gene, was associated with fear-related phenotypes in a highly traumatized human cohort. Results We demonstrate that approximately half of the neurons in the amygdala express SR, including both excitatory and inhibitory neurons. We find that the acquisition and extinction of fear memory engages the SR/D-serine system in the mouse amygdala and that D-serine administration facilitates fear extinction. We also demonstrate that the SRR single nucleotide polymorphism, rs4523957, is associated with posttraumatic stress disorder in humans, consistent with the facilitatory effect of D-serine on fear extinction. Conclusions These new findings have important implications for understanding D-serine–mediated N-methyl-D-aspartate receptor plasticity in the amygdala and how this system could contribute to disorders with maladaptive fear circuitry. |
| Databáze: | OpenAIRE |
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