Munc13-2 differentially affects hippocampal synaptic transmission and plasticity.
The short-term dynamics of synaptic communication between neurons provides neural networks with specific frequency-filter characteristics for information transfer. The direction of short-term synaptic plasticity, that is, facilitation versus depression, is highly dependent on and inversely correlated to the basal release probability of a synapse. Amongst the processes implicated in shaping the release probability, proteins that regulate the docking and priming of synaptic vesicles at the active zone are of special importance. Here, we found that a member of the Munc13 protein family of priming proteins, namely Munc13-2, is essential for normal release probability at hippocampal mossy fiber synapses. Paired pulse and frequency facilitation were strongly increased, whereas mossy fiber long-term potentiation was unaffected in the absence of Munc13-2. In contrast, transmission at 3 other types of hippocampal synapses, Schaffer-collateral, associational-commissural, as well as inhibitory synapses onto CA3 pyramidal neurons was unaffected by the loss of Munc13-2.
Breustedt
J
J
Neurowissenschaftliches Forschungszentrum, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
Gundlfinger
A
A
Varoqueaux
F
F
Reim
K
K
Brose
N
N
Schmitz
D
D
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D003521:Cyclopropanes / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000235:genetics; D018756:GABA Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology*; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D019599:Mossy Fibers, Hippocampal / Q000187:drug effects / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D011724:Pyridazines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D003521:Cyclopropanes; D004151:Dipeptides; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D011724:Pyridazines; D011810:Quinoxalines; C485549:Unc13b protein, mouse; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C082313:2-(2,3-dicarboxycyclopropyl)glycine; C028929:gamma-glutamylglycine; C049853:gabazine; D002118:Calcium; D005998:Glycine