Oxytocin facilitates the induction of long-term potentiation in the accessory olfactory bulb.
When female mice are mated, they form a memory to the pheromonal signal of their male partner. Several lines of evidence indicate that the neural changes underlying this memory occur in the accessory olfactory bulb (AOB) at the first stage of the vomeronasal system. The formation of this memory depends on the mating-induced release of noradrenaline in the AOB. In addition to noradrenaline, the neuropeptide oxytocin (OT) is also released within the central nervous system during mating. Because OT has been implicated in social memory and its receptors are expressed in the AOB, we hypothesized that OT might promote the strength of synaptic transmission from mitral to granule cells in the AOB. To test this hypothesis, we analyzed the lateral olfactory tract-evoked field potential that represents the granule cell response to mitral cell activation and its plasticity in parasagittal slices of the AOB. Of the 10-, 20-, 50-, and 100-Hz stimulations tested, the 100-Hz stimulation was optimal for inducing long-term potentiation (LTP). OT paired with 100-Hz stimulation that only produced short-term potentiation enhanced LTP induction in a dose-dependent manner. OT-paired LTP was blocked by both the selective OT antagonist desGly-NH(2),d(CH(2))(5)[Tyr(Me)(2),Thr(4)]-ornithine vasotocin and the N-methyl-d-aspartate (NMDA) receptor antagonist dl-2-amino-5-phosphonovaleric acid. These results indicate that OT can function as a gate to modulate the establishment of NMDA receptor-dependent LTP at the mitral-to-granule cell synapse in the AOB.
Fang
Long-Yun
LY
Department of Physiology, Kochi Medical School, Nankoku, Kochi 783-8505, Japan.
Quan
Rong-Dan
RD
Kaba
Hideto
H
D000818:Animals; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009833:Olfactory Pathways / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques; D010121:Oxytocin / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D012724:Sex Attractants / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D014668:Vasotocin / Q000031:analogs & derivatives / Q000494:pharmacology; D019147:Vomeronasal Organ / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D012724:Sex Attractants; D010121:Oxytocin; D014668:Vasotocin