Glutamate-mediated primary somatosensory cortex excitability correlated with ceruloplasmin in healthy subjects

Objective: To investigate the biological processes linked to metal
homeostasis which underlie glutamate-mediated neurotrasmission of the
primary somatosensory cortex, as marked by the neuronal pool generating
the earliest component (M20) of somatosensory field evoked (SEF) by right
median nerve stimulation at wrist.
Method: Thirty-four healthy right-handed subjects (51±22 years)
underwent a magnetoencephalography (MEG) examination. A source reconstruction
algorithm was applied to assess the amount of synchronously
activated neurons subtending the M20 and the following SEF component
(M30), which is generated by two independent contributions of gabaergic
and glutamatergic transmission. Serum copper, ceruloplasmin, nonceruloplasmin-
bound copper ('free'), iron, transferrin and zinc levels
were evaluated.
Results: Total copper and ceruloplasmin negatively correlated with the
M20 ECD strength. A transferrin M20 ECD strength correlation only
approached significance.
Conclusion: This pilot study showed that copper homeostasis, rather than
iron or zinc status seems to be involved in the physiological activities
of glutamate-mediated neurotransmission of the primary somatosensory
cortex.