Nigrostriatal Pathway

Summary

The nigrostriatal pathway is a dopaminergic pathway that connects the substantia nigra of the midbrain to the striatum of the forebrain. It plays key roles in motor control as a part of the basal ganglia system. This dopamine pathway is inhibited in Parkinson disease. Impairment of nigrostriatal signaling is also the cause of extrapyramidal symptoms with antipsychotic drugs.

Key Points

• Nigrostriatal Pathway
  • Dopaminergic Pathway
    • Connects the substantia nigra pars compacta (SNc) in midbrain with dorsal striatum (caudate nucleus and putamen) in the basal ganglia
  • Function
    • Motor control
      • Critical in the function of the basal ganglia, regulating voluntary motor movements
  • Lesions
    • Inhibited in Parkinson Disease
      • Degeneration of substantia nigra leads to reduced signaling
    • Inhibited with Extrapyramidal Symptoms (of antipsychotics)
      • D2 antagonism by antipsychotic drugs cause off target inhibition of dopamine signaling in the nigrostriatal pathway, leading to symptoms including dystonia, akathisia, parkinsonism, tardive dyskinesia