在Aplysia突触中,先前和后突触机制的参与导致了Aplysia突触的前性和后性强化
J X Bao1, E R Kandel, R D Hawkins
1Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
概括
隔膜后强化 (PTP) 是一种突触可塑性的形式,通常被视为突触前. 这项研究揭示了PTP还涉及后突触机制,挑战了长期以来仅存在的前突触理论.
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
- 突触性可塑性 突触性可塑性
背景情况:
- 隔膜后增强 (PTP) 是一种成熟的短期突触可塑性的形式.
- 传统上,PTP仅归因于影响神经递质释放的前突触机制.
研究的目的:
- 为了研究在Aplysia感觉运动神经元突触中PTP背后的精确机制.
- 为了确定PTP是否仅涉及突触前组件,或者突触后因素是否有所贡献.
主要方法:
- 实验使用Aplysia感觉运动神经元突触在细胞培养中.
- 进行了胆剂的先和后注射.
- 诱导了 postsynaptic 超极化以评估其对 PTP 的影响.
主要成果:
- 预突触合酶降低了PTP,增加了自发刺激后突触潜力的频率,但不是振幅.
- 快速化剂的后交互注射也减少了PTP.
- 后突触超极化同样减少了PTP,表明后突触参与.
结论:
- 这些突触中的PTP并非完全由突触前机制调解.
- 一个后突触诱导机制对PTP有显著的贡献.
- 这些发现需要对短期突触可塑性的理解进行修订.
相关概念视频
Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Hebbian LTP
LTP can occur when presynaptic neurons...
Hebbian LTP
LTP can occur when presynaptic neurons...
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...
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...
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...


