R L Dorris

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Locomotor activity of ten squirrel monkeys, Saimiri sciureus, was evaluated by means of a photocell activity cage following intracranial application of dopamine (DA). A biphasic response consisting of an initial quiet period followed by increased locomotor activity was seen following intra-accumbens DA, 12.5--100 micrograms bilaterally. Both the length of(More)
Release of 3H-d-alpha-methyl-m-tyramine (3H-MMTA), a false dopaminergic transmitter, from rat striatum was studied in vitro. After its initial uptake, 3H-MMTA was released by high K+ and by amphetamine. The release requirements were essentially the same as those known to exist for release of dopamine in vitro. These studies indicate that 3H-MMTA might serve(More)
The relative decrease in the 2 h accumulation of administered [3H]-spiperone (SPI)-2 muCi/kg, 0.0004 mg/kg, s.c. - in mouse corpus striatum, a brain area with a high dopaminergic input (specific plus nonspecific dopamine receptor ligand binding) and the cerebellum, a brain area with little, if any, dopaminergic input (an index of nonspecific dopamine(More)
Nitrous oxide increases locomotor activity in mice. Other locomotor stimulants are thought to act via central dopaminergic mechanisms and can be divided into two groups as determined by their antagonism by tyrosine hydroxylase inhibitors or by reserpine pretreatment. The purpose of the present study was to determine if nitrous oxide fits one or the other of(More)
Mice were exposed to nitrous oxide (50%) for up to 24 h and S-adenosylmethionine (SAMe) levels measured in corpus striatum and cerebellum, areas with high and low catecholamine turnover rates, respectively. After 4 h, levels were 21 and 8% and after 6 h, 33 and 14% lower than controls in striatum and cerebellum, respectively. Thus, the effect was more(More)
The i.p. injection of 3-methoxybenzamide (3-MBA) in rats produces a dose-related elevation of the threshold for response to a painful stimulus. Metoclopramide, also a substituted benzamide, has analgesic activity that is attenuated by bromocriptine, a dopamine receptor agonist, and by the narcotic antagonist, naloxone, suggesting involvement of dopamine and(More)
[3H]-Spiperone (20 microCi/kg, 0.0003 mg/kg, SC) was administered to mice. Relative decreases in the 2-hr ratio of accumulation of this dopamine receptor radioligand in the dopaminergic corpus striatum ("specific" plus "nonspecific binding") and the nondopaminergic cerebellum ("nonspecific binding" only) were used to evaluate nicotinamide for possible(More)
[3H]Spiperone was administered (20 microCi/kg, 0.0003 mg/kg, sc) to mice. In agreement with other published reports, 2 hr later the accumulation of tritium was three to four times greater in the corpus striatum than in the cerebellum. Ascorbic acid (100, 1000, 2000 mg/kg, ip, 30 min) reduced the 2-hr accumulation in the corpus striatum 16, 42, and 63%,(More)