| Project/Area Number |
13831011
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生体生命情報学
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| Research Institution | Kyoto Sangyo University |
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Principal Investigator |
ITO Hiroyuki Kyoto Sangyo University, Faculty of Engineerings, Professor, 工学部, 教授 (80201929)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2001: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | unitary event / synchronus firing / spike synchrony / lateral geniculate nucleus / visual cortex / oscillatory activities / tetrode / correlated firing / 視覚情報処理 / 多細胞同時記録 / 多側膝状体 / 時空間解析 / スパイク統計 |
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| Research Abstract |
Several studies have shown that cells in the visual cortex (A17) of the cat display stimulus-evoked oscillatory firings (30-60Hz) and synchronization among multiple cells. Previously we reported that the cells in the lateral geniculate nucleus (LGN) also showed stimulus evoked synchronous oscillatory firings of higher frequency range (60-100Hz). The difference in their frequency ranges suggested that the oscillatory activity in the cortex was not likely to derive from that in the LGN. On the other hand, Gray et al. reported a transient nature of the synchronization of the oscillatory local field potentials in the cortex, that is, the transition between asynchronous and synchronous states could occur within a trial duration. For further comparison of the synchronization between the two areas, we investigated whether such temporal modulation (non-stationarity) exists also in the -synchronization in the LGN. Since the traditional method of the cross-correlogram loses any information on the non-stationarity by the temporal averaging ovei-the trial duration, we adopted the unitary event (UE) analysis to trace the dynamics of the spike synchrony. We found that also in the LGN, a reasonable portion of synchronous activities was non-stationary even under the presentation of the stationary spot stimulus. The modulation of the number of the UEs had apparently different time scale (less than a few hundred milliseconds) from the rate modulations of the two cells. This result may suggest that the synchrony plays a different functional role from the firing rate in the visual information processing. Furthermore, the unitary event analysis was applied to the spike trains of individual trials. We found a rather large variability and transiency in both the magnitude and the duration of the unitary events over different trials.
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