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Communication networks in the brain: neurons, receptors, neurotransmitters, and alcohol.

Lovinger DM - Alcohol Res Health (2008)

Bottom Line: Hundreds of molecules are known to act as neurotransmitters in the brain.Neuronal development and function also are affected by peptides known as neurotrophins and by steroid hormones.It focuses on neurotransmitters with important roles in acute and chronic alcohol effects on the brain, such as those that contribute to intoxication, tolerance, dependence, and neurotoxicity, as well as maintained alcohol drinking and addiction.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Integrative Neuroscience at the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland.

ABSTRACT
Nerve cells (i.e., neurons) communicate via a combination of electrical and chemical signals. Within the neuron, electrical signals driven by charged particles allow rapid conduction from one end of the cell to the other. Communication between neurons occurs at tiny gaps called synapses, where specialized parts of the two cells (i.e., the presynaptic and postsynaptic neurons) come within nanometers of one another to allow for chemical transmission. The presynaptic neuron releases a chemical (i.e., a neurotransmitter) that is received by the postsynaptic neuron's specialized proteins called neurotransmitter receptors. The neurotransmitter molecules bind to the receptor proteins and alter postsynaptic neuronal function. Two types of neurotransmitter receptors exist-ligand-gated ion channels, which permit rapid ion flow directly across the outer cell membrane, and G-protein-coupled receptors, which set into motion chemical signaling events within the cell. Hundreds of molecules are known to act as neurotransmitters in the brain. Neuronal development and function also are affected by peptides known as neurotrophins and by steroid hormones. This article reviews the chemical nature, neuronal actions, receptor subtypes, and therapeutic roles of several transmitters, neurotrophins, and hormones. It focuses on neurotransmitters with important roles in acute and chronic alcohol effects on the brain, such as those that contribute to intoxication, tolerance, dependence, and neurotoxicity, as well as maintained alcohol drinking and addiction.

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Related in: MedlinePlus

Schematic drawing of a synapse between two neurons. Synaptic vesicles contain a neurotransmitter (NT) and release it when their membranes fuse with the outer cell membrane. Neurotransmitter molecules cross the synaptic cleft and bind to receptors known as ligand-gated ion channels (LGICs) and G-protein–coupled receptors (GPCRs) on the postsynaptic neuron. GPCRs on the presynaptic neuron’s axon terminal alter the function of voltage-gated ion channels and modulate neurotransmitter release. Neurotransmitter transporters remove neurotransmitter molecules from the synaptic cleft so that they can be repackaged into vesicles.
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f2-arh-31-3-196: Schematic drawing of a synapse between two neurons. Synaptic vesicles contain a neurotransmitter (NT) and release it when their membranes fuse with the outer cell membrane. Neurotransmitter molecules cross the synaptic cleft and bind to receptors known as ligand-gated ion channels (LGICs) and G-protein–coupled receptors (GPCRs) on the postsynaptic neuron. GPCRs on the presynaptic neuron’s axon terminal alter the function of voltage-gated ion channels and modulate neurotransmitter release. Neurotransmitter transporters remove neurotransmitter molecules from the synaptic cleft so that they can be repackaged into vesicles.

Mentions: Individual neurons usually are completely separated from one another by their outer cell membranes and thus cannot directly share electrical or chemical signals. The exception to this situation is the so-called electrical synapse, in which ion-conducting pores made from proteins called connexins connect the intracellular compartments of adjacent neurons, allowing direct ion flow from cell to cell (Kandel et al. 2000). This form of interneuronal communication is much less common in the mammalian CNS than chemical transmission and will not be discussed any further. Rather, the focus will be on chemical interneuronal communication involving the release of a neurotransmitter from one neuron, which alters the activity of the receiving neuron. This chemical communication usually occurs at a specialized structure called a synapse, where parts of the two cells are brought within 20 to 50 nanometers of one another (see figure 2). The neuron that releases the chemical is called the presynaptic neuron. A specialized structure at the tip of the axon of the presynaptic neuron, termed the axon terminal, contains small packets known as vesicles, which are filled with neurotransmitter molecules. When an action potential reaches the axon terminal and stimulates a rise in the concentration of calcium, this ion stimulates the vesicle to fuse with the cell membrane and release the neurotransmitter into the small synaptic gap between cells.


Communication networks in the brain: neurons, receptors, neurotransmitters, and alcohol.

Lovinger DM - Alcohol Res Health (2008)

Schematic drawing of a synapse between two neurons. Synaptic vesicles contain a neurotransmitter (NT) and release it when their membranes fuse with the outer cell membrane. Neurotransmitter molecules cross the synaptic cleft and bind to receptors known as ligand-gated ion channels (LGICs) and G-protein–coupled receptors (GPCRs) on the postsynaptic neuron. GPCRs on the presynaptic neuron’s axon terminal alter the function of voltage-gated ion channels and modulate neurotransmitter release. Neurotransmitter transporters remove neurotransmitter molecules from the synaptic cleft so that they can be repackaged into vesicles.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3860493&req=5

f2-arh-31-3-196: Schematic drawing of a synapse between two neurons. Synaptic vesicles contain a neurotransmitter (NT) and release it when their membranes fuse with the outer cell membrane. Neurotransmitter molecules cross the synaptic cleft and bind to receptors known as ligand-gated ion channels (LGICs) and G-protein–coupled receptors (GPCRs) on the postsynaptic neuron. GPCRs on the presynaptic neuron’s axon terminal alter the function of voltage-gated ion channels and modulate neurotransmitter release. Neurotransmitter transporters remove neurotransmitter molecules from the synaptic cleft so that they can be repackaged into vesicles.
Mentions: Individual neurons usually are completely separated from one another by their outer cell membranes and thus cannot directly share electrical or chemical signals. The exception to this situation is the so-called electrical synapse, in which ion-conducting pores made from proteins called connexins connect the intracellular compartments of adjacent neurons, allowing direct ion flow from cell to cell (Kandel et al. 2000). This form of interneuronal communication is much less common in the mammalian CNS than chemical transmission and will not be discussed any further. Rather, the focus will be on chemical interneuronal communication involving the release of a neurotransmitter from one neuron, which alters the activity of the receiving neuron. This chemical communication usually occurs at a specialized structure called a synapse, where parts of the two cells are brought within 20 to 50 nanometers of one another (see figure 2). The neuron that releases the chemical is called the presynaptic neuron. A specialized structure at the tip of the axon of the presynaptic neuron, termed the axon terminal, contains small packets known as vesicles, which are filled with neurotransmitter molecules. When an action potential reaches the axon terminal and stimulates a rise in the concentration of calcium, this ion stimulates the vesicle to fuse with the cell membrane and release the neurotransmitter into the small synaptic gap between cells.

Bottom Line: Hundreds of molecules are known to act as neurotransmitters in the brain.Neuronal development and function also are affected by peptides known as neurotrophins and by steroid hormones.It focuses on neurotransmitters with important roles in acute and chronic alcohol effects on the brain, such as those that contribute to intoxication, tolerance, dependence, and neurotoxicity, as well as maintained alcohol drinking and addiction.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Integrative Neuroscience at the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland.

ABSTRACT
Nerve cells (i.e., neurons) communicate via a combination of electrical and chemical signals. Within the neuron, electrical signals driven by charged particles allow rapid conduction from one end of the cell to the other. Communication between neurons occurs at tiny gaps called synapses, where specialized parts of the two cells (i.e., the presynaptic and postsynaptic neurons) come within nanometers of one another to allow for chemical transmission. The presynaptic neuron releases a chemical (i.e., a neurotransmitter) that is received by the postsynaptic neuron's specialized proteins called neurotransmitter receptors. The neurotransmitter molecules bind to the receptor proteins and alter postsynaptic neuronal function. Two types of neurotransmitter receptors exist-ligand-gated ion channels, which permit rapid ion flow directly across the outer cell membrane, and G-protein-coupled receptors, which set into motion chemical signaling events within the cell. Hundreds of molecules are known to act as neurotransmitters in the brain. Neuronal development and function also are affected by peptides known as neurotrophins and by steroid hormones. This article reviews the chemical nature, neuronal actions, receptor subtypes, and therapeutic roles of several transmitters, neurotrophins, and hormones. It focuses on neurotransmitters with important roles in acute and chronic alcohol effects on the brain, such as those that contribute to intoxication, tolerance, dependence, and neurotoxicity, as well as maintained alcohol drinking and addiction.

Show MeSH
Related in: MedlinePlus