2006 Fiscal Year Final Research Report Summary
Molecular mechanisms of dynamic changes in memory traces
| Project/Area Number |
16300100
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neuroscience in general
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| Research Institution | Kochi University |
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Principal Investigator |
KABA Hideto Kochi University, Faculty of Medicine, Professor, 医学部, 教授 (50136371)
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| Co-Investigator(Kenkyū-buntansha) |
OKUTANI Fumino Kochi University, Faculty of Medicine, Associate Professor, 医学部, 助教授 (10194490)
MURAMOTO Kazuyo Kochi University, Faculty of Medicine, Assistant Professor, 医学部, 助手 (10301798)
TANIGUCHI Mutsuo Kochi University, Faculty of Medicine, Assistant Professor, 医学部, 助手 (10304677)
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| Project Period (FY) |
2004 – 2006
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| Keywords | pheromone / odour / memory / learning / protein phosphatase / oxytocin / long-term potentiation / vomeronasal receptor |
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| Research Abstract |
When a female is mated with a male partner, she forms a memory to the urinary pheromones of the male, thereby preventing his pheromones from inducing pregnancy block. The neural changes underlying this memory occur in the accessory olfactory bulb (AOB), the first relay in the vomeronasal system, depend upon mating-induced enhancement of alpha2-adrenergic transmission in the AOB and involve changes at the reciprocal synapses between mitral and granule cells. In this study, we demonstrate that oxytocin facilitates the induction of long-term potentiation at the mitral-to-granule cell synapse.
We have established a procedure for the co-culture of vomeronasal sensory neurons (VSNs) with AOB neurons. Our data suggest that the differentiation and/or maturation of VSNs and AOB neurons are both stimulated or modified by the co-culture. By examining the expression of V2R-type vomeronasal receptors (VR1 and VR2) and chemosensory responsiveness in the vomeronasal organ cocultured with AOB neurons, we demonstrate that AOB neurons induce the expression of vomeronasal receptors in VSNs, allowing them to function.
On postnatal day 12, young rats show an aversion to an odour to which they had been exposed along with presentations of foot shock on postnatal day 11. By infusing the protein phosphatase 1 (PP1) inhibitor, inhibitor-2 into the olfactory bulb (OB) during odour-shock training, we demonstrate that PP1 is involved in the extinction process of aversive olfactory learning. We have shown that cyclic AMP response element binding protein (CREB) and its phosphorylation in the OB are required for the long-term, but not the short-term, facilitation process of this olfactory learning. CREB phosphorylation has been shown to induce histone acetylation. In this study, we demonstrate that histone acetylation in the OB is involved in the acquisition process of this olfactory learning.
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