Nearly one million people living in the U.S. suffer from Parkinson’s disease (PD), a chronic disorder of the central nervous system that affects movement. PD can be treated by various means, none of which can reverse the effects of the disease.

Researchers at Emory University in Atlanta, for the first time, systematically recorded neural activity in the striatum, the part of the brain that deals with cognitive and motor functions. The study published Monday in the Proceedings of the National Academy of Sciences, revealed that these two functions are compromised in PD patients causing neuron-firing abnormalities.

Researchers compared the striatal recordings of people with PD and the striatal recordings of patients diagnosed with other neurological disorders with corresponding findings in primates.

“We found profound changes in the activity of striatal projection neurons in patients with PD, which highlighted the striatal role in circuit dysfunction,” lead researcher for the study Stella Papa said in a statement. The current basal ganglia circuit models of PD are based on presumptive changes in the outputs of the dopamine-depleted striatum which were never found in human studies, she said.

“The data we are providing in this new study have long been due and weigh significantly in the interpretation of striatal mechanisms in basal ganglia circuits and their contribution to the pathophysiology of PD,” Papa added.

Researchers are now investigating the physiological and molecular mechanisms that take part in the abnormal neuron-firing. Understanding this, the researchers said, will help in developing target-specific treatments to help people who have PD.