Parkinson's disease (PD) is a neurological condition representing the second most common neurodegenerative disorder after Alzheimer's disease. Although the cause of neuronal degeneration is not known, it is accepted that the motor symptoms of PD are due to the degeneration of dopaminergic neurons in the pars compacta of the substantia nigra. In addition, PD is also characterized by the manifestation of non-motor symptoms that may occur even before the motor symptoms, which may be due to impaired function in the noradrenergic and/or serotonergic systems. However, the exact role and mechanisms of involvement of these systems in the pathogenesis and pathophysiology of the disease remain to be determined.

The proposed issue invites papers across, but not limited to, the following themes:

• Is there a role of the noradrenergic and/or serotonergic system in the pathophysiology of motor symptoms

• Is there a role of the noradrenergic and/or serotonergic system in the pathophysiology of non-motor symptoms

• Are there any novel drugs targeting these monoaminergic systems in the treatment of PD

• Is there any potential role of noradrenaline in neuroprotection against dopaminergic neurodegeneration

• Are the noradrenergic and serotonergic systems involved in the mechanism of L-Dopa-induced dyskinesia in PD

Keywords: Parkinson’s disease; dopamine; noradrenaline; serotonin; cell death; neuroprotection; motor symptoms; non-motor symptoms; risk-factors in PD