Frequency Dependence of Excitatory Synaptic Transmission

兴奋性突触传递的频率依赖性

• 批准号: 6685906
• 负责人: LYNN E DOBRUNZ
• 金额: $ 25.38万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6685906
• 关键词: action potentials; brain electrical activity; computational neuroscience; electrophysiology; electrostimulus; hippocampus; interneurons; laboratory rat; neural plasticity; neural transmission; pyramidal cells; synapses; voltage /patch clamp

DESCRIPTION (provided by applicant): At excitatory synapses onto CA1 pyramidal cells, short-term plasticity causes synaptic strength to be modulated over a wide range in response to irregular stimulus patterns such as these synapses receive in vivo. This frequency-dependence of synaptic transmission enables computation at synapses, and determines the content of information transmitted between the pre- and post-synaptic cells. Very little is known, however, about short-term plasticity and frequency-dependence of synaptic transmission at excitatory synapses onto CA1 interneurons. Like CA1 pyramidal cells, interneurons in CA1 receive inputs from CA3 pyramidal cells via Schaffer collateral axons. However, the role of interneurons in the hippocampal circuit is quite different. Since these cells provide critical feed forward inhibition to the CA1 pyramidal cells, the frequency-dependence of their excitatory inputs will be crucial in determining the balance of excitation and inhibition in the circuit. The balance between inhibition and excitation is critical to the hippocampus, a brain region that is highly susceptible to epilepsy. Experiments in this proposal use electrophysiology to compare short-term plasticity and the frequency dependence of synaptic transmission at excitatory synapses onto CA1 interneurons vs. pyramidal cells, using traditional stimulus paradigms and temporally complex stimulus patterns based on in vivo recordings of action potential timing. These experiments will provide information about the role of the postsynaptic target cell in determining presynaptic properties, and how the frequency dependence of synaptic transmission is related to neural coding.

描述（由申请人提供）：在对CA1锥体细胞上的兴奋性突触时，短期可塑性会导致突触强度在广泛的范围内调节，以响应不规则的刺激模式，例如这些突触在体内接收。突触传播的这种频率依赖性可以在突触时进行计算，并确定在突触前和突触后细胞之间传递的信息的内容。然而，关于兴奋性突触在CA1中间神经元上的突触传播的短期可塑性和频率依赖性知之甚少。像CA1锥体细胞一样，CA1中的中间神经元通过Schaffer侧支轴突从CA3锥体细胞接收输入。但是，中间神经元在海马电路中的作用截然不同。由于这些细胞对CA1锥体细胞提供了关键的进食抑制作用，因此其兴奋性输入的频率依赖性对于确定电路中激发和抑制的平衡至关重要。抑制和激发之间的平衡对于海马是高度容易受到癫痫的大脑区域的海马。该提案中的实验使用电生理学来比较兴奋性突触在CA1中间神经元与金字塔细胞上的短期可塑性和突触传播的频率依赖性，并使用传统的刺激范式和基于动作潜在的动作潜在计时的动作记录的传统刺激范式和时间复杂的刺激模式。这些实验将提供有关突触后靶细胞在确定突触前特性以及突触传播的频率依赖性与神经编码有关的信息。