A pharmacological and genetic blockade of the
dopamine D3 receptor (D3R) has shown to be neuroprotective in models of
Parkinson's disease (PD). The
anxiolytic drug buspirone, a
serotonin receptor 1A agonist, also functions as a potent D3R antagonist. To test if
buspirone elicited neuroprotective activities, C57BL/6 mice were subjected to
rotenone treatment (10mg/kg i.p for 21 days) to induce PD-like pathology and were co-treated with increasing dosages of
buspirone (1, 3, or 10 mg/kg i.p.) to determine if the
drug could prevent
rotenone-induced damage to the central nervous system (CNS). We found that high dosages of
buspirone prevented the behavioural deficits caused by
rotenone in the open field test. Molecular and histological analyses confirmed that 10 mg/kg of
buspirone prevented the degeneration of TH-positive neurons.
Buspirone attenuated the induction of interleukin-1β and
interleukin-6 expression by
rotenone, and this was paralleled by the upregulation of arginase-1,
brain-derived neurotrophic factor (
BDNF), and activity-dependent neuroprotective
protein (ADNP) in the midbrain, striatum, prefrontal cortex, amygdala, and hippocampus.
Buspirone treatment also improved mitochondrial function and
antioxidant activities. Lastly, the
drug prevented the disruptions in the expression of two neuroprotective
peptides,
pituitary adenylate cyclase-activating polypeptide (
PACAP) and
vasoactive intestinal peptide (VIP). These results pinpoint the neuroprotective efficacy of
buspirone against
rotenone toxicity, suggesting its potential use as a therapeutic agent in neurodegenerative and
neuroinflammatory diseases, such as PD.