Oscillations of gene expression and physiological activity in suprachiasmatic nucleus (SCN) neurons result from auto-regulatory feedback loops of circadian clock gene transcription factors. In the present experiment, we have determined the pattern of PERIOD1, PERIOD2 and CLOCK expression within neuroendocrine dopaminergic neurons (NDNs) of ovariectomized (OVX) rats. We have also determined the ...

Replacement of the degenerated dopamin-ergic input by grafted dopamine (DA) producing cells has been proposed as an effective therapy for Parkinson's disease (PD). However, results from clinical application of fetal DA grafts were rather disappointing since transplantation resulted only in slight functional improvement/1/. Prolonged treatment with L-dopa or DA agonists might, via stimulation of...

background: parkinson’s disease (pd) is a common neurodegenerative disease resulting from the degeneration of dopaminergic (da) neurons in the substantia nigra pars compacta (snc). increasing evidence demonstrated that mice treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp) suffered impairments in motor functions associated with disruption of da neurons in snc conceiv...

Trehalose, as a natural disaccharide, is known as an autophagy inducer. The neuroprotectiveeffects of trehalose in the rat model of Parkinson′s disease were the aim of the present study.Parkinson′s disease model was induced by injecting 6-hydroxydopamine (6-OHDA) in thestriatum of male Wistar rats. Apomorphine-induced behavior and substantia nigra neuronalcounts were app...

background: oleuropein is a phenolic compound which is present in the olive leaf extract. the purpose of the present study was to investigate the neuroprotective effect of oleuropein as an antioxidant agent on the substantia nigra in aged rats. methods: twenty 18-month-old wistar rats (450-550 g) were randomly divided into control and experimental groups. the experimental group received a daily...

background and objective: parkinson's disease (pd) is characterized by a progressive loss of dopaminergic neurons in substantia nigra. in recent years, there have been interests in the role of the free radical damage in pd. cinnamon and its derivative, cinnamaldehyde acts as powerful antioxidant and anti-inflammatory agents. this research focused on the effects of cinnamon extract and cinn...

The relatively few dopaminergic (DA) neurons in the mammalian brain regulate many important neural functions, including motor integration, neuroendocrine hormone release, cognition, emotive behaviors and reward. A number of laboratories, including ours, have contributed to unravel the mechanisms of DA phenotype induction and maturation and elucidated the role of epigenetic factors involved in s...

Parkinson's disease (PD) is characterized by the selective vulnerability of the nigrostriatal dopaminergic circuit. Recently, loss-of-function mutations in the PTEN-induced kinase 1 (PINK1) gene have been linked to early-onset PD. How PINK1 deficiency causes dopaminergic dysfunction and degeneration in PD patients is unknown. Here, we investigate the physiological role of PINK1 in the nigrostri...

Increasing attention is now focused on reduced dopaminergic neurotransmission in the forebrain as participating in depression. The present paper assessed whether effective antidepressant (AD) treatments might counteract, or compensate for, such a change by altering the neuronal activity of dopaminergic neurons in the ventral tegmental area (VTA-DA neurons), the cell bodies of the mesocorticolim...

Dysfunctions of dopaminergic homeostasis leading to either low or high dopamine (DA) levels are causally linked to Parkinson's disease, schizophrenia, and addiction. Major sites of DA synthesis are the mesencephalic neurons originating in the substantia nigra and ventral tegmental area; these structures send major projections to the dorsal striatum (DSt) and nucleus accumbens (NAcc), respective...