Hippocampal Fyn activity regulates extinction of contextual fear.

Tomoko Isosaka, Satoshi Kida, Tomoko Kohno, Kotaro Hattori, Shigeki Yuasa

Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.

Neuroreport 2009 Oct 28

filter terms:

Contextual fear memory is attenuated by reexposure of animals to a context alone without pairing it with an unconditioned stimulus, a phenomenon referred to as fear extinction. Here, we report that Fyn tyrosine kinase in the hippocampus is involved in the extinction of contextual fear. We inhibited Src-family tyrosine kinases in the dorsal hippocampus by stereotaxic injection of an inhibitor, PP2, and observed facilitation of extinction. We then biochemically analyzed dorsal hippocampal tissue during extinction training, and found that activated Fyn was significantly downregulated among the Src-family tyrosine kinases examined. These findings suggest that downregulation of Fyn activity facilitates the extinction of contextual fear.

Citation

Tomoko Isosaka, Satoshi Kida, Tomoko Kohno, Kotaro Hattori, Shigeki Yuasa. Hippocampal Fyn activity regulates extinction of contextual fear. Neuroreport. 2009 Oct 28;20(16):1461-5