Dopamine-dependent tuning of striatal inhibitory synaptogenesis.
Dopaminergic projections to the striatum, crucial for the correct functioning of this brain region in adulthood, are known to be established early in development, but their role is currently uncharacterized. We demonstrate here that dopamine, by activating D(1)- and/or D(2)-dopamine receptors, decreases the number of functional GABAergic synapses formed between the embryonic precursors of the medium spiny neurons, the principal output neurons of the striatum, with associated changes in spontaneous synaptic activity. Activation of these receptors reduces the size of postsynaptic GABA(A) receptor clusters and their overall cell-surface expression, without affecting the total number of clusters or the size or number of GABAergic nerve terminals. These changes result from an increased internalization of GABA(A) receptors, and are mediated by distinct signaling pathways converging at the level of GABA(A) receptors to cause a transient PP2A/PP1-dependent dephosphorylation. Thus, tonic D(1)- and D(2)-receptor activity limits the extent of collateral inhibitory synaptogenesis between medium spiny neurons, revealing a novel role of dopamine in controlling the development of intrinsic striatal microcircuits.
Goffin
Darren
D
Department of Pharmacology, The School of Pharmacy, University of London, London, United Kingdom.
Ali
Afia B
AB
Rampersaud
Nazir
N
Harkavyi
Alexander
A
Fuchs
Celine
C
Whitton
Peter S
PS
Nairn
Angus C
AC
Jovanovic
Jasmina N
JN
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D003342:Corpus Striatum / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011940:Receptor Aggregation / Q000502:physiology; D011954:Receptors, Dopamine / Q000378:metabolism; D011963:Receptors, GABA-A / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D011954:Receptors, Dopamine; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; D010749:Phosphoprotein Phosphatases; D004298:Dopamine