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Dopamine D1 receptor inhibition of NMDA receptor currents mediated by tyrosine kinase‐dependent receptor trafficking in neonatal rat striatum
Author(s) -
Tong Huaxia,
Gibb Alasdair J.
Publication year - 2008
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2008.158931
Subject(s) - dopamine receptor d1 , dopamine receptor d2 , nmda receptor , striatum , dopamine , dopamine receptor , chemistry , receptor , ror1 , receptor tyrosine kinase , microbiology and biotechnology , medicine , neuroscience , endocrinology , biology , biochemistry , platelet derived growth factor receptor , growth factor
NMDA receptors are of particular importance in the control of synaptic strength and integration of synaptic activity. Dopamine receptor modulation of NMDA receptors in neonatal striatum may influence the efficacy of synaptic transmission in the cortico‐striatal pathway and if so, this modulation will affect the behaviour of the basal ganglia network. Here, we show that in acute brain slices of neonatal (P7) rat striatum the dopamine D1 receptor agonist SKF‐82958 significantly decreases NMDA receptor currents in patch‐clamp whole‐cell recordings. This inhibition is not abolished by application of a G protein inhibitor (GDP‐β‐S) or irreversible G protein activator (GTP‐γ‐S) suggesting a G protein‐independent mechanism. In addition, intracellular application of protein tyrosine kinase inhibitors (lavendustin A or PP2) abolished D1 inhibition of NMDA currents. In contrast, in older animals (P28) D1 receptor activation produces a potentiation of the NMDA response which suggests there is a developmental switch in D1 modulation of striatal NMDA receptors. Single‐channel recordings show that direct D1 receptor inhibition of NMDA receptors cannot be observed in isolated membrane patches. We hypothesize that D1 inhibition in whole‐cell recordings from neonatal rats may be mediated by a change in NMDA receptor trafficking. Consistent with this hypothesis, intracellular application of a dynamin inhibitory peptide (QVPSRPNRAP) abolished D1 inhibition of NMDA receptor currents. We therefore conclude that a tyrosine kinase‐dependent alteration of NMDA receptor trafficking underlies D1 dopamine receptor‐mediated down‐regulation of NMDA receptor currents in medium spiny neurons of neonatal rat striatum.