Erythropoietin is implicated in the regulation of the neural control of breathing. Unilateral micro-injection of erythropoietin in the Locus coeruleus attenuates the hypercapnia-induced hyperpnea. Unilateral micro-injection of erythropoietin in the Locus coeruleus has a long-term effect in the attenuation of the hypercapnia-induced hyperpnea.