Linked Life Data

18691636

Source:http://linkedlifedata.com/resource/pubmed/id/18691636

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-9-15
pubmed:abstractText
Noradrenaline (NA) modulates glutamatergic and GABAergic transmission in various areas of the brain. It is reported that some alpha2-adrenoceptor subtypes are expressed in the cerebellar cortex and alpha2-adrenoceptors may play a role in motor coordination. Our previous study demonstrated that the selective alpha2-adrenoceptor agonist clonidine partially depresses spontaneous inhibitory postsynaptic currents (sIPSCs) in mouse cerebellar Purkinje cells (PCs). Here we found that the inhibitory effect of clonidine on sIPSCs was enhanced during postnatal development. The activation of alpha2-adrenoceptors by clonidine did not affect sIPSCs in PCs at postnatal days (P) 8-10, when PCs showed a few sIPSCs and interneurons in the molecular layer (MLIs) did not cause action potential (AP). In the second postnatal week, the frequency of sIPSCs increased temporarily and reached a plateau at P14. By contrast, MLIs began to fire at P11 with the firing rate gradually increasing thereafter and reaching a plateau at P21. In parallel with this rise in the rate of firing, the magnitude of the clonidine-mediated inhibition of sIPSCs increased during postnatal development. Furthermore, the magnitude of the clonidine-mediated firing suppression in MLIs, which seemed to be mediated by a reduction in amplitude of the hyperpolarization-activated nonselective cation current, I(h), was constant across development. Both alpha2A- and alpha2B-, but not alpha2C-, adrenoceptors were strongly expressed in MLIs at P13, and P31. Therefore, the developmental enhancement of the clonidine-mediated inhibition of sIPSCs is attributed to an age-dependent increase in AP-derived sIPSCs, which can be blocked by clonidine. Thus, presynaptic activation of alpha2-adrenoceptors inhibits cerebellar inhibitory synaptic transmission after the second postnatal week, leading to a restriction of NA signaling, which is mainly mediated by alpha1- and beta2-adrenoceptors in the adult cerebellar neuronal circuit.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
156
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
143-54
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:18691636-Action Potentials, pubmed-meshheading:18691636-Adrenergic alpha-Agonists, pubmed-meshheading:18691636-Aging, pubmed-meshheading:18691636-Animals, pubmed-meshheading:18691636-Animals, Newborn, pubmed-meshheading:18691636-Cell Differentiation, pubmed-meshheading:18691636-Cerebellar Cortex, pubmed-meshheading:18691636-Clonidine, pubmed-meshheading:18691636-Female, pubmed-meshheading:18691636-Inhibitory Postsynaptic Potentials, pubmed-meshheading:18691636-Interneurons, pubmed-meshheading:18691636-Male, pubmed-meshheading:18691636-Mice, pubmed-meshheading:18691636-Mice, Inbred C57BL, pubmed-meshheading:18691636-Neural Inhibition, pubmed-meshheading:18691636-Norepinephrine, pubmed-meshheading:18691636-Organ Culture Techniques, pubmed-meshheading:18691636-Protein Isoforms, pubmed-meshheading:18691636-Purkinje Cells, pubmed-meshheading:18691636-Receptors, Adrenergic, alpha-2, pubmed-meshheading:18691636-Synaptic Transmission
pubmed:year
2008
pubmed:articleTitle
Developmental enhancement of alpha2-adrenoceptor-mediated suppression of inhibitory synaptic transmission onto mouse cerebellar Purkinje cells.
pubmed:affiliation
Neuronal Circuit Mechanisms Research Group, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. hironom@brain.riken.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't