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Calcium‐activated non‐selective cation currents are involved in generation of tonic and bursting activity in dopamine neurons of the substantia nigra pars compacta
Author(s) -
Mrejeru Ana,
Wei Aguan,
Ramirez Jan Marino
Publication year - 2011
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.2011.206631
Subject(s) - pars compacta , substantia nigra , neuroscience , bursting , dopamine , chemistry , nmda receptor , transient receptor potential channel , glutamatergic , bapta , medium spiny neuron , glutamate receptor , dopaminergic , biology , receptor , striatum , biochemistry
Non‐technical summary The loss of dopamine‐containing neurons within the substantia nigra has been implicated in Parkinson's disease. Thus, the question why these neurons are particularly vulnerable to excitotoxicity has received considerable attention. Under physiological conditions dopamine neurons can generate a burst of activity that seems to require NMDA receptors and that is activated by high frequency glutamatergic inputs. Here, we show in a brain slice preparation of mice that NMDA receptor activation further excites the neurons by recruiting a calcium‐activated non‐selective cation current ( I CAN ) and we hypothesize that I CAN is specifically mediated by a transient receptor potential (TRP) channel. We used RT‐PCR methods to confirm expression of TRPM2 and TRPM4 mRNA in substantia nigra pars compacta. We propose that I CAN is selectively activated during burst firing to boost NMDA currents and allow plateau potentials. This boost mechanism may render DA cells vulnerable to excitotoxicity.