TY - JOUR T1 - Impairment of Catecholamine Systems during Induction of Long-Term Potentiation at Hippocampal CA1 Synapses in HPC-1/Syntaxin 1A Knock-out Mice JF - The Journal of Neuroscience JO - J. Neurosci. SP - 381 LP - 389 DO - 10.1523/JNEUROSCI.2911-11.2012 VL - 32 IS - 1 AU - Tatsuya Mishima AU - Tomonori Fujiwara AU - Takefumi Kofuji AU - Kimio Akagawa Y1 - 2012/01/04 UR - http://www.jneurosci.org/content/32/1/381.abstract N2 - The membrane protein HPC-1/syntaxin 1A is believed to play a key role in synaptic vesicle exocytosis, and it was recently suggested to be required for synaptic plasticity. Despite evidence for the function of HPC-1/syntaxin 1A in synaptic plasticity, the underlying cellular mechanism is unclear. We found that although fast synaptic transmission and long-term depression were unaffected, HPC-1/syntaxin 1A knock-out (STX1A−/−) mice showed impaired long-term potentiation (LTP) in response to theta-burst stimulation in CA1 hippocampal slices. The impairment in LTP was rescued by the application of forskolin, an adenylyl cyclase activator, or more robust stimulation, suggesting that cAMP/protein kinase A signaling was suppressed in these mice. In addition, catecholamine release from the hippocampus was significantly reduced in STX1A−/− mice. Because HPC-1/syntaxin 1A regulates exocytosis of dense-core synaptic vesicles, which contain neuromodulatory transmitters such as noradrenaline, dopamine and 5-HT, we examined the effect of neuromodulatory transmitters on LTP induction. Noradrenaline and dopamine enhanced LTP induction in STX1A−/− mice, whereas catecholamine depletion reduced LTP induction in wild-type mice. Theses results suggest that HPC-1/syntaxin 1A regulates catecholaminergic systems via exocytosis of dense-core synaptic vesicles, and that deletion of HPC-1/syntaxin 1A causes impairment of LTP induction. ER -