まとめ
エタノールは,カエルの神経筋肉の交差点にあるニコチンアセチルコリン受容体の機能に影響します. 生理学的に重要な濃度であっても,アルコールはアセチルコリンに対する受容体の反応を変化させます.
科学分野:
- 神経科学は神経科学である.
- 薬理学 薬理学とは
- 分子生物学は分子生物学である.
背景:
- アルコールの中枢神経系への影響の分子メカニズムは,ほとんど不明のままである.
- エタノールが軸索のアクションポテンシャルに与える影響は,中央効果を引き起こす濃度をはるかに超える濃度を必要とする.
- エタノールは,カエルの神経筋肉の交差点にあるニコチンアセチルコリン受容体の開閉時間を増加させることが示されています.
研究 の 目的:
- エタノールが,カエルの神経筋結節のポストシナプス膜に及ぼす影響を調査する.
- エタノールがアセチルコリンとその受容体間の相互作用にどのように影響するかを理解する.
主な方法:
- アセチルコリン受容体 (ACh) とACH受容体のバランス状態の投与量反応曲線の測定.
- モデルシステムとしてカエルの神経筋肉の交差点を利用する.
主要な成果:
- エタノールは,ACh受容体の機能的性質を大幅に変化させます.
- 生理学的に許容されるエタノール濃度 (0.2%) は,ACH受容体の投与量反応曲線に測定可能な影響を及ぼします.
結論:
- エタノールは,シナプス後のニコチンアセチルコリン受容体の機能に直接影響を与えます.
- これらの発見は,関連する濃度でのアルコールの神経学的効果の分子機構の洞察を提供します.
関連する概念動画
01:29Excitatory 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...
01:26Chemical 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...
01:29Neuromuscular Junction And Blockade
The site of chemical communication between a motor neuron and a muscle fiber is called the neuromuscular junction (NMJ). The end of the motor neuron at the NMJ divides into a cluster of synaptic end bulbs. The cytoplasm of these bulbs consists of synaptic vesicles enclosing acetylcholine molecules, the principal neurotransmitter released at the NMJ. The region opposite the synaptic bulb that ends in the muscle fiber is called the motor end plate, which has acetylcholine receptors. Within the...
01:29Relaxation of Skeletal Muscles
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
01:26Chemical 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...
01:28Integration 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...