There he worked on the physiology of hemidecorticated animals and neurovegetative control, with several important physiologists, such as Phillip Bard, Carl Richter and Vernon Mountcastle.
Under Covian's able and humane leadership, the Department would grow to become one of the main excellence centers of research and education in Latin America, with an excellent scientific staff, with prominent researchers such as Eduardo Krieger, Renato Migliorini, César Timo-Iaria, José Antunes Rodrigues, José Venâncio Pereira Leite and fellow Argentines Maria Carmelo Lico, Andrés Negro-Vilar and Ricardo F. Marseillan.
Covian's main achievement in neurophysiology was the systematic study, with a large group of collaborators, of the neural basis of thirst, of neuroendocrine regulation of hydroelectrolytic homeostasis, and of appetitive behavior, i.e., the behavior which permit animals to seek and to ingest particular foodstuffs or diet components, an activity which depends on many external and internal factors.
The animal model used by Covian's group was the selective ingestion of water versus salt water in albino Norwegian rats, which they investigated with many approaches and tools, such as after lesions and stimulations of the central nervous system, measurement of metabolic activity, manipulation of the activity of the endocrine system, the effect of several kinds of drugs, etc.
He retired at the mandatory age of 70, as a professor emeritus, but continued to appear regularly his office in the department Honored by his many colleagues, pupils and friends, Covian died on February 5, 1992, following complications of a stroke.