background: melatonin has receptors in substantia nigra pars compacta (snc) and regulates development of dopaminergic (da) neurons. this study was undertaken to determine ability of melatonin to protect snc dopaminergic neuron loss induced by estrogen deficiency in ovariectomized rats. methods: female rats were randomized into four groups of seven each: control, ethanol sham, ovariectomy (ovx) ...

Background: Melatonin has receptors in substantia nigra pars compacta (SNc) and regulates development of dopaminergic (DA) neurons. This study was undertaken to determine ability of melatonin to protect SNc dopaminergic neuron loss induced by estrogen deficiency in ovariectomized rats. Methods: Female rats were randomized into four groups of seven each: control, ethanol sham, ovariectomy (ovx) ...

neural stem cells (nscs) as a heterogeneous multipotent and self- renewal population are found in different areas in the developing mammalian nervous system, as well as the sub-ventricular zone (svz) and the hippocampus of the adult brain. nscs can give rise to neurons, astrocytes and oligodendrocytes. the aim of this study was to differentiate neural stem cells into noradrenergic–like cells in...

The transport of norepinephrine and two key enzymes involved in its synthesis, tyrosine hydroxylase (EC 1.14.3a) and dopamine beta-hydroxylase (EC 1.14.2.1), has been studied in relation to other axonal constituents in ligated chicken sciatic nerves. Norepinephrine, tyrosine hydroxylase, and dopamine beta-hydroxylase activity all increased proximal to the constriction over a 20-hr period. The r...

Biogenic amines play an important role in brain metabolism and functioning, participation synaptic transmission as neurotransmitters neuromodulators (dopamine, serotonin, histamine others). Catecholamines are formed from the essential amino acid phenylalanine by hydroxylating it to tyrosine with enzyme phenylalanine-4-hydroxylase, which is subsequently converted dioxyphenylalanine (DOPA) tyrosi...

neuromelanin (nm) pigment accumulates with age in catecholaminergic neurons in man, and the ventral substantia nigra dopaminergic neurons that are the most vulnerable to degeneration in parkinson's disease (pd) contain the greatest amount of this pigment. in vitro data indicate that nm pigment is formed from the excess cytosolic catecholamine that is not accumulated into synaptic vesicles via t...

1. Activity of peripheral and central catecholaminergic neurons was studied in spontaneously hypertensive rats (SHR) and deoxycorticosterone (DOCA)-salt hypertensive rats. 2. In young SHR (4 weeks) the plasma values of bpth noradrenaline and dopamine-beta-hydroxylase activity were increased compared with those of normotensive rats of the Wistar/Kyoto strain. Total catecholamines (mostly adrenal...

Exposure to chemosensory signals from unfamiliar males can terminate pregnancy in recently mated female mice. The number of tyrosine hydroxylase-positive neurons in the main olfactory bulb has been found to increase following mating and has been implicated in preventing male-induced pregnancy block during the post-implantation period. In contrast, pre-implantation pregnancy block is mediated by...

Data from preclinical and clinical studies have implicated the norepinephrine system in the development and maintenance of post-traumatic stress disorder. The primary source of norepinephrine in the forebrain is the locus coeruleus (LC); however, LC activity cannot be directly measured in humans, and previous research has often relied upon peripheral measures of norepinephrine to infer changes ...