Salt TE; Turner JP; Kingston AE; (1999)
Evaluation of agonists and antagonists acting at Group I metabotropic glutamate receptors in the thalamus in
vivo. Neuropharmacology, 38: 1505-1510.
Recordings were made from single neurones in the ventrobasal thalamus of anaesthetised rats in order to evaluate the
properties of several agonists and antagonists of Group I mGlu receptors. The selective mGlu1 receptor antagonist LY367385
was found to reduce excitatory responses to iontophoretically applied ACPD and DHPG whereas the mGlu5 agonist CHPG
was resistant to antagonism. The antagonists LY367366 and LY393053 reduced responses to all three agonists, but without
reducing responses to NMDA or AMPA. Although AIDA was also found to reduce mGlu agonist-evoked responses, this
antagonist also produced significant reductions in responses to NMDA and AMPA. These data suggest that there are
functional mGlu1 and mGlu5 receptors in the thalamus. Furthermore, LY367385 is a useful tool for investigating mGlu1
functions whereas LY367366 and LY393053 have a broader spectrum of action. The usefulness of AIDA as an antagonist in
physiological experiments would appear to be limited by its effects against NMDA and AMPA.
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