Abstract
Medium spiny projection neurons (MSNs) are the main neuronal population in the neostriatum. MSNs are inhibitory and GABAergic. MSNs connect with other MSNs via local axon collaterals that produce lateral inhibition, which is thought to select cell assemblies for motor action. MSNs also receive inhibitory inputs from GABAergic local interneurons. This work shows, through the use of the paired pulse protocol, that somatostatin (SST) acts presynaptically to regulate GABA release from the terminals interconnecting MSNs. This SST action is reversible and not mediated through the release of dopamine. It is blocked by the SST receptor (SSTR) antagonist ciclosomatostatin (cicloSST). In contrast, SST does not regulate inhibition coming from interneurons. Because, SST is released by a class of local interneuron, it is concluded that this neuron helps to regulate the selection of motor acts.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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6-Cyano-7-nitroquinoxaline-2,3-dione / metabolism
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Action Potentials / physiology
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Animals
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Corpus Striatum / cytology
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Corpus Striatum / metabolism*
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Excitatory Amino Acid Agonists / metabolism
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Excitatory Amino Acid Antagonists / metabolism
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Inhibitory Postsynaptic Potentials / physiology*
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N-Methylaspartate / metabolism
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Neurons / cytology
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Neurons / metabolism*
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Patch-Clamp Techniques
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Presynaptic Terminals / metabolism*
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Rats
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Rats, Wistar
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Somatostatin / metabolism*
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Valine / analogs & derivatives
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Valine / metabolism
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / metabolism
Substances
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Excitatory Amino Acid Agonists
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Excitatory Amino Acid Antagonists
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Somatostatin
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N-Methylaspartate
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6-Cyano-7-nitroquinoxaline-2,3-dione
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2-amino-5-phosphopentanoic acid
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
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Valine