bioeng_admin
2004-10-12 20:15:43
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학과 세미나를 아래와 같이 개최하오니 많이들 참석하여 주시기 바랍니다.
- 아 래 -
- 발표자: Keun-Hang Yang (양근향 박사, NIH 연구원)
- 세미나 제목:
Inhibition Modifies the Effects of Slow Calcium-Activated
Potassium Channels on Epileptiform Activity in a Neuronal
Network Model
- 일 자: 7월 6일 화요일 4시
- 장 소: 정문술빌딩 2층 217호
- 초 록:
Inhibition Modifies the Effects of Slow Calcium-Activated Potassium Channels on Epileptiform Activity in a Neuronal Network Model
Keun-Hang Yang 1,2, Piotr J. Franaszczuk2, and Gregory K. Bergey2
1Laboratory of Neural Control, Section on Developmental Neurobiology, National Institute of Neurological Disorders and Stroke
National Institutes of Health, Bethesda, Maryland, USA
2Department of Neurology, Johns Hopkins Epilepsy Center, Johns Hopkins
University School of Medicine, Baltimore, Maryland, USA
Abstract
Generation of epileptiform activity typically results from a change in the balance between network excitation and inhibition. Experimental evidence indicates that alterations of either synaptic activity or intrinsic membrane properties can produce increased network excitation. The slow Ca2+ - activated K+ currents (sIAHP) are important modulators of neuronal firing rate and excitability and have important established and potential roles in epileptogenesis. While the effects of changes of sIAHP on individual neuronal excitability are readily studied and well established, the effects of such changes on network behavior are less well known. The experiments here, utilize a defined small network model of multicompartment pyramidal cells and an inhibitory interneuron, to study the effects of changes on sIAHP on network behavior. The benefits of this model system include the ability to observe activity in all cells in the network and the effects of interactions of multiple simultaneous influences. In the model with no inhibitory interneuron, increasing sIAHP results in progressively decreasing burst activity. Adding an inhibitory interneuron changes the observed effects; at modest inhibitory strengths, increasing sIAHP in all network neurons actually results in increased network bursting (except at very high values). The duration of the burst activity is influenced by the length of delay in a feedback loop, with longer loops resulting in more prolonged bursting. These observations illustrate that the study of potential antiepileptogenic membrane effects must be extended to realistic networks. Network inhibition can dramatically alter the observations seen in pure excitatory networks.
- 아 래 -
- 발표자: Keun-Hang Yang (양근향 박사, NIH 연구원)
- 세미나 제목:
Inhibition Modifies the Effects of Slow Calcium-Activated
Potassium Channels on Epileptiform Activity in a Neuronal
Network Model
- 일 자: 7월 6일 화요일 4시
- 장 소: 정문술빌딩 2층 217호
- 초 록:
Inhibition Modifies the Effects of Slow Calcium-Activated Potassium Channels on Epileptiform Activity in a Neuronal Network Model
Keun-Hang Yang 1,2, Piotr J. Franaszczuk2, and Gregory K. Bergey2
1Laboratory of Neural Control, Section on Developmental Neurobiology, National Institute of Neurological Disorders and Stroke
National Institutes of Health, Bethesda, Maryland, USA
2Department of Neurology, Johns Hopkins Epilepsy Center, Johns Hopkins
University School of Medicine, Baltimore, Maryland, USA
Abstract
Generation of epileptiform activity typically results from a change in the balance between network excitation and inhibition. Experimental evidence indicates that alterations of either synaptic activity or intrinsic membrane properties can produce increased network excitation. The slow Ca2+ - activated K+ currents (sIAHP) are important modulators of neuronal firing rate and excitability and have important established and potential roles in epileptogenesis. While the effects of changes of sIAHP on individual neuronal excitability are readily studied and well established, the effects of such changes on network behavior are less well known. The experiments here, utilize a defined small network model of multicompartment pyramidal cells and an inhibitory interneuron, to study the effects of changes on sIAHP on network behavior. The benefits of this model system include the ability to observe activity in all cells in the network and the effects of interactions of multiple simultaneous influences. In the model with no inhibitory interneuron, increasing sIAHP results in progressively decreasing burst activity. Adding an inhibitory interneuron changes the observed effects; at modest inhibitory strengths, increasing sIAHP in all network neurons actually results in increased network bursting (except at very high values). The duration of the burst activity is influenced by the length of delay in a feedback loop, with longer loops resulting in more prolonged bursting. These observations illustrate that the study of potential antiepileptogenic membrane effects must be extended to realistic networks. Network inhibition can dramatically alter the observations seen in pure excitatory networks.
