概括
在Aplysia中,两个内部神经元在单个追随细胞中控制激发和抑制. 一个单一的神经递质,乙胆,对两个不同的受体起作用,产生这些相反的效应.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 神经生理学 神经生理学
背景情况:
- 内神经元在调节神经电路活动中起着至关重要的作用.
- 了解突触传输机制是神经科学的基础.
研究的目的:
- 研究Aplysia中单个内部神经元调解激发和抑制的机制.
- 描述参与这些双重反应的不同后突触受体.
主要方法:
- 来自Aplysia口腔质神经元的电生理学记录.
- 在已识别的内部神经元中,单个动作潜能后的突触潜能分析.
- 乙胆和胆阻断剂的离子化应用.
主要成果:
- 鉴定到的内部神经元在追随细胞中引起了二相 (去极化-超极化) 突触潜能.
- 确定了两个不同的后突触受体,具有不同的逆转潜力和离子导电量.
- 激发性成分涉及导电,而抑制性成分涉及导电.
- 这两种突触潜能成分都被乙胆和特定胆作用剂模仿并差异地阻断.
结论:
- 一个单一的神经递质作用于多种受体类型可以调解相反的突触后效应.
- 这种机制提供了一种复杂的方式来调节Aplysia.的神经元输出.
- 这些受体的差异性质允许微调神经元通信.
相关概念视频
Postsynaptic Potential (PSP)
Postsynaptic potential (PSP) refers to a change in the electrical potential of a neuron when neurotransmitters released by presynaptic neurons bind to postsynaptic receptors. This potential can either be excitatory, leading to depolarization and ultimately action potential generation, or inhibitory, leading to hyperpolarization and suppression of the postsynaptic neuron.
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Integration of Synaptic Events
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...
Excitatory and Inhibitory Effects of Neurotransmitters
When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of specific...
The Synapse
Neurons communicate with one another by passing on their electrical signals to other neurons. A synapse is the location where two neurons meet to exchange signals. At the synapse, the neuron that sends the signal is called the presynaptic cell, while the neuron that receives the message is called the postsynaptic cell. Note that most neurons can be both presynaptic and postsynaptic, as they both transmit and receive information.


