Suppression of exaggerated neuronal oscillations by oxytocin in a rat model of Parkinson’s disease

Abstract

Abstract.Increased oscillatory activity has been demonstrated in the basal ganglia of Parkinson's disease (PD) patients. The aim of the present study was to evaluate the effects of oxytocin (OT) on local field potentials (LFPs) in a rotenone-induced rat model of PD. Adult male Sprague-Dawley rats were unilaterally injected with rotenone (3 µg/µl in DMSO) into the left substantia nigra pars compacta whereas vehicle group was received only DMSO. PD-developed rats were then administered either OT (160 µg/kg/day, i.p.) or saline for three weeks. Following treatment period, LFPs were recorded from the left striatum of freely moving rats and neuronal cell loss was evaluated by Nissl staining. We found significant increase in all frequency bands except delta in saline group when compared with vehicle (p < 0.0005), while treatment of OT prevented these alterations in electroencephalography (EEG) recordings. Besides, histopathological evaluation of the striatal sections revealed a significant cell loss (p < 0.005), whereas administration of rats with OT significantly lessened the neuronal death. These findings suggest that injury of dopaminergic neurons triggers exaggerated neuronal oscillations in the striatum and oxytocin may have some inhibitory effects on neuronal activity in PD.

Heteromerization of Dopamine D2 and Oxytocin Receptor in Adult Striatal Astrocytes

“…Consistently, a reduction of the number of OT-immunoreactive neurons in the hypothalamus of PD patients [97], and the ability of OT to influence locomotor activity at the level of the substantia nigra [98], possibly suggest that a decrease of OT levels in the brain areas receiving oxytocinergic projections may play a role in the motor disabilities in PD patients [98]. Accordingly, OT was reported to possess neuroprotective effects on rotenone-induced PD in rats [99,100] or in MPTP-treated mice [101]. In fact, OT could allow the astrocytic D2 receptor's activation by low extracellular levels of dopamine and could rescue the reduced activation of the D2 receptors (by a defective dopaminergic transmission in PD).…”

Electrophysiological evaluation of oxytocin’s effects on basolateral amygdala

“…[21] Erba ve ark. [22,23] rotenon ile oluturulan Parkinson modelinde oksitosinin sinir koruyucu etkilerini ve Parkinsonda artan striatal elektriksel aktivite artıını azalttı¤ını göstermilerdir. Erba ve ark.…”