Dear Colleagues,

Dopamine (DA) plays a vital role in normal brain processes including memory, motor behavior and reward. Loss of dopaminergic neurons in the substantia nigra contributes to Parkinson's disease, while overactive dopaminergic signaling is an important factor in the positive symptoms of schizophrenia. Hence, dopamine receptors (DRS) are primary targets in the treatment of neurodegenerative diseases such as schizophrenia, Parkinson's disease and Huntington's disease.

DRs are categorized into two classes according to the signals they mediate: D1-like (D1, D5) and D2-like (D2, D3, D4) receptors. DA acts on these receptor families to modulate cellular excitability and synaptic plasticity in a circuit-specific manner, thus ultimately controlling motor behaviors. It has been speculated that cAMP is the primary messenger for DRs in dopamine signaling. However, the complexity in DR crystal structure and signaling provides exciting new avenues for the discovery of antipsychotic drugs. Although current drugs can effectively treat the positive symptoms of schizophrenia, these medications are less effective at treating negative symptoms and cognitive deficits. Hence, there is a critical need to discover and develop novel therapies. The aim of this special issue is to provide an update on the current research status of DRs and on novel trends in this field and future perspectives.

Dr. Pradeep Paudel

Guest Editor