Phrenic motoneuron expression of serotonergic and glutamatergic receptors following upper cervical spinal cord injury

► Motoneuron neurotransmitter receptor mRNA levels increase after spinal cord injury. ► Serotonergic 5-HTR2a receptors increase ~ 8-fold 14 days post-C2 hemisection. ► Glutamatergic NMDA receptors increase ~ 16 fold by 21 days post-C2 hemisection. ► Motoneuron expression of 5-HTR2a and 5-HTR2c receptors is positively correlated. ► Motoneuron expression of AMPA and NMDA receptors is negatively correlated.