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Subsaturation of the N‐methyl‐D‐aspartate receptor glycine site allows the regulation of bursting activity in juvenile rat nigral dopamine neurons
Author(s) -
Destreel Geoffrey,
Seutin Vincent,
Engel Dominique
Publication year - 2019
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.14491
Subject(s) - nmda receptor , excitatory postsynaptic potential , pars compacta , bursting , neurotransmission , dopamine , postsynaptic potential , substantia nigra , neuroscience , glycine , glutamate receptor , chemistry , biology , inhibitory postsynaptic potential , receptor , dopaminergic , biochemistry , amino acid
The activation of N‐methyl‐D‐aspartate receptors ( NMDAR s) in substantia nigra pars compacta ( SN c) dopamine ( DA ) cells is central to generate the bursting activity, a phasic signal linked to DA ‐related behaviours via the change in postsynaptic DA release. NMDAR s are recruited during excitatory synaptic transmission by glutamate release, but the glycine site level of occupancy of these receptors during basal action potential‐dependent activity is not known for SN c DA neurons. We explored NMDAR ‐dependent signals during exogenous applications of co‐agonists in midbrain slices from juvenile rats. We found that both glycine and D‐serine strengthened the NMDAR ‐dependent component of excitatory postsynaptic currents ( EPSC s) in a concentration‐dependent manner. EPSC s were also increased by endogenous glycine via the blockade of the glycine transport. The glycine site of NMDAR s contributing to synaptic transmission is therefore subsaturated. The behaviourally relevant burst firing was more sensitive to exogenous D‐serine and endogenous glycine than to exogenous glycine. The mechanisms regulating the availability of the co‐agonists exert consequently a critical influence on the excitability of DA neurons via NMDAR s. The modulation of the phasic firing in DA neurons by ambient NMDAR co‐agonists may be important for nigral information processing and downstream motor‐related behaviour.