Glutamate-Mediated Primary Somatosensory Cortex Excitability Correlated with Circulating Copper and Ceruloplasmin

Figure 1

MEG primary sensorimotor cortex excitability indexes. Top left: in a representative subject, the superimposition of all left rolandic region channels in the [−20, 100] ms period, 0 being the moment of the galvanic stimulus arrival to the right median nerve at wrist. Top right: the position of the ECDs explaining the cerebral activation in correspondence to the M20 (white circle) and M30 (black circle) components is projected onto a suitable axial magnetic resonance image slice, through integration on the basis of individual anatomical landmarks. Bottom: schematic representation of currents subtending M20 and M30 generators in a suitable sagittal section of primary sensory and motor areas. Orange arrow indicates current induced by EPSP and purple arrow the effect of IPSP. Circles represent the position of the corresponding equivalent current dipole. The M20 component is mainly generated by EPSPs impinging on pyramidal neurons in area 3b and is mediated by glutamate neurotransmitters. The currents associated with the IPSPs impinging on pyramidal neurons in 3b area are mediated by GABA neurotransmitter and are added to the EPSPs onto BA4 pyramidal neurons to give rise to M30 component.