Calcitriol protection against dopamine loss induced by intracerebroventricular administration of 6-hydroxydopamine.

Calcitriol has been implicated as an agent that has neuroprotective effects in various animal models of diseases, possibly by upregulating glial cell line-derived neurotrophic factor (GDNF). The present study examined the neuroprotective effects of calcitriol in a model of early Parkinson's disease. Rats were treated daily with calcitriol or saline for 7 days before an intraventricular injection of 6-hydroxydopamine (6-OHDA), and then for 1 day or daily for 3(1/2) to 4 weeks after lesioning.

Striatal trophic factor activity in aging monkeys with unilateral MPTP-induced parkinsonism.

Striatal trophic activity was assessed in female rhesus monkeys of advancing age rendered hemiparkinsonian by unilateral intracarotid administration of MPTP. Three age groups were analyzed: young adults (8-9.5 years) n=4, middle-aged adults (15-17 years) n=4, and aged adults (21-31 years) n=7.

Neurotrophic and neuroprotective effects of the neuregulin glial growth factor-2 on dopaminergic neurons in rat primary midbrain cultures.

Glial growth factor-2 (GGF2) and other neuregulin (NRG) isoforms have been shown to play important roles in survival, migration, and differentiation of certain neural and non-neural cells. Because midbrain dopamine (DA) cells express the NRG receptor, ErbB4, the present study examined the potential neurotrophic and/or neuroprotective effects of GGF2 on cultured primary dopaminergic neurons. Embryonic day 14 rat mesencephalic cell cultures were maintained in serum-free medium and treated with GGF2 or vehicle.

Supranigral injection of neuregulin1-beta induces striatal dopamine overflow.

Previous studies have provided anatomical evidence that the functional neuregulin receptor, ErbB4, is present within the ventral midbrain where it is co-localized to dopamine neurons of the substantia nigra and ventral tegmental area. In this study, we provide evidence that neuregulin1-beta (a.k.

Comparison of embryonic stem cell-derived dopamine neuron grafts and fetal ventral mesencephalic tissue grafts: morphology and function.

In this study we compared the function and morphology of two types of neural grafts: allografts of fetal ventral mesencephalic (VM) tissue and xenografts of embryonic stem cell (ESC)-derived dopamine neurons. Mouse embryonic stem cells were cultured and exposed to differentiation factors that induced approximately 10% of the cells to express a dopaminergic phenotype. These cells were then harvested and implanted into the denervated striatum of rats with unilateral lesions of the nigrostriatal pathway.

Temporal changes in the neurotrophic environment of the denervated striatum as determined by the survival and outgrowth of grafted fetal dopamine neurons.

There is growing evidence that the neurotrophic environment of the denervated striatum may change with time following a lesion of the nigrostriatal pathway in young adult rats. To test this hypothesis, we implanted fetal dopamine grafts into the striatum at several different time points relative to the nigrostriatal pathway lesion and allowed the grafts to integrate with the host for a period of 1 month; subsequently, we observed the function and morphology of the dopamine grafts. Fetal grafts were implanted at the following time points relative to the lesion: 1 week before (-1 Week), at the same time (Week 0), 1 week after (1 Week), 4 weeks after (4 Weeks), or 12 weeks after (12 Weeks).