title: Long-term depression at olfactory nerve synapses.
abstract: The synapses formed by the olfactory nerve (ON) convey sensory information to olfactory glomeruli, the first stage of central odor processing. Morphological and behavioral studies suggest that glomerular odor processing is plastic in neonate rodents. However, long-term synaptic plasticity, a cellular correlate of functional and structural plasticity, has not yet been demonstrated in this system. Here, we report that ON-->mitral cell (MC) synapses of 5- to 8-d-old mice express long-term depression (LTD) after brief low-frequency ON stimulation. Pharmacological techniques and imaging of presynaptic calcium signals demonstrate that ON-MC LTD is expressed presynaptically and requires the activation of metabotropic glutamate receptors but does not require fast synaptic transmission. LTD at the ON--> MC synapse is potentially relevant for the establishment, maintenance, and experience-dependent refinement of odor maps in the olfactory bulb.
authors.affiliation: Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-0198, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Mutoh
authors.forename: Qi
authors.initials: Q
authors.lastname: Yuan
authors.forename: Thomas
authors.initials: T
authors.lastname: Knöpfel
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D003952:Diagnostic Imaging / Q000379:methods; D018492:Dopamine Antagonists / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D036881:Long-Term Synaptic Depression / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000166:cytology*; D009830:Olfactory Bulb / Q000166:cytology*; D018408:Patch-Clamp Techniques / Q000379:methods; D011810:Quinoxalines / Q000494:pharmacology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013469:Sulpiride / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
chemical_list: D018492:Dopamine Antagonists; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D026941:Sodium Channel Blockers; C474696:methyl-(4-carboxyphenyl)glycine; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D013779:Tetrodotoxin; D008734:Methoxyhydroxyphenylglycol; D016202:N-Methylaspartate; C056639:2-amino-5-phosphopentanoic acid; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D013469:Sulpiride; D014633:Valine; D002118:Calcium; D005998:Glycine; C010117:3,4-dihydroxyphenylglycol