= Abstract = Immobilization stress was adopted as a prototype stress model for studying the effects of stress on dopaminergic and noradrenergic neuronal activity in the rat hypothalamus. Norepinephrine content was significantly increased after 4 hours of immobilization stress. Also, the turnover rates of both dopamine and norepinephrine were found to be significantly increased after the stress,...

Rat brain tyrosine hydroxylase exists in two distinct physical forms, a soluble and a membrane-bound form, The two forms are brain-region specific, with the membranebound or particulate form predominating in the striatum, an area enriched in catecholamine nerve endings and associated with a specific membrane fraction. Whereas the soluble and the particulate enzymes exhibit an identical Km for t...

From the results of previous studies in which developing peripheral ganglia from quail embryos were transplanted into younger chicken embryo hosts, we concluded that spinal and cranial sensory ganglia contain dormant precursors with autonomic potentialities. Here we describe the differentiation of these precursors in vitro, from dorsal root and nodose ganglion cell suspensions. Dorsal root gang...

Initial studies are reported on the catecholamine metabolism of low-density cultures of dissociated primary sympathetic neurons. Radioactive tyrosine was used to study the synthesis and breakdown of catecholamines in the cultures. The dependence of catecholamine synthesis and accumulation on external tyrosine concentration was examined and a concentration which is near saturation, 30 microM, wa...