Parkinson’s disease (PD) is usually thought of as a motor disorder, although non-motor symptoms may precede the motor manifestations and are a key component of the PD. Among these, depression and anxiety are most prevalent symptoms and caused a greater symptomatic burden in women than in men. A dysfunctional serotonin (5-HT) system is generally considered a risk factor for depression. We propose the ventromedial prefrontal cortex (vmPFC)-dorsal raphe nucleus (DR) circuit as the key player underlying depressive/anxious disorders in PD, by virtue of its reciprocal connectivity. Female mice overexpressing human alpha-synuclein mutant A53T (h-α-Syn) were evaluated in 5-HT neurons of the DR at 4 and 8 weeks. Several behavioral tests were performed to assess anxiety and depressive phenotype. Neuronal activity of infralimbic (IL) and prelimbic (PL) cortex was assessed in awake head-fixed mice using a multichannel probe and a virtual reality corridor. Synaptic markers and h-α-Syn expression were also examined. Female h-α-Syn mice developed an anxiety-like phenotype and anhedonia, which was reversed by ketamine. In parallel, h-α-Syn mice also showed alterations in synaptic markers (SV2A, MAP-2, BDNF) and changes in PL and IL electrophysiological neuronal activity, which may contribute to neuropsychiatric symptoms.h-α-Syn overexpression in DR 5-HT neurons in female mouse model triggers alteration in the activity of vmPFC-DR circuit, which in turn result in depressive/anxiety-like phenotype.Support: PID2022-141700OB-I00 MCIN/AEI/ 10.13039/501100011033 and “ERDF A way of making Europe”;AGAUR_SGR21-01358 Generalitat de Catalunya;2023 BBRF Young Investigator Grant(31547); Margarita Salas grants for the training of young doctors (University of Valencia, MS21-132).