RT Journal Article
SR Electronic
T1 Neuropsin (KLK8)-Dependent and -Independent Synaptic Tagging in the Schaffer-Collateral Pathway of Mouse Hippocampus
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 843
OP 849
DO 10.1523/JNEUROSCI.4397-07.2008
VO 28
IS 4
A1 Ishikawa, Yasuyuki
A1 Horii, Yoichiro
A1 Tamura, Hideki
A1 Shiosaka, Sadao
YR 2008
UL http://www.jneurosci.org/content/28/4/843.abstract
AB Hippocampal early long-term potentiation (LTP) elicited by a weak (one or two) tetanic stimulus normally fades away within 90 min. Late LTP elicited by strong (four) stimuli lasts >180 min and requires new protein synthesis to persist. If a strong tetanus is injected once into a synapse, even a weak tetanus injected into another synapse can evoke persistent LTP. It was hypothesized that a synaptic tag enables capture of newly synthesized synaptic molecules. Here, we found two synaptic capture mechanisms for a weakly stimulated synapse to acquire persistency (i.e., neuropsin dependent and independent). The single tetanus evokes a neuropsin-dependent form that follows downstream signaling into integrin/actin signal and L-type voltage-dependent Ca2+ channel (LVDCC) pathway. Additionally, a neuropsin-independent form of synaptic capture is evoked by a stronger (two) tetanus than the former. Both forms converging on LVDCC might serve different associative memories depending on their input strength. Our study strongly supports the hypothesis of synaptic tagging and demonstrates that neuropsin-dependent late associativity is particularly important in nonstressful associative memory.