Control pigeons showed high mRNA levels of the glutamatergic NMDA receptor subunits GRIN1 and GRIN2B and the AMPA receptor subunits GRIA2 and GRIA3, while from the monoaminergic receptors, the dopaminergic DRD1A receptor subtype showed the highest concentration in the HF. This evidence concerns the gene GRIN2B and hydrops fetalis.