James Severson

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[3H]Spiroperidol and [3H]ADTN ( 2-amino-l,7-dihydroxy-1,2,3,4-tetra hydronaphthalene) binding were used to assay for dopamine receptors in aged C57BL/6J mouse striatal membranes. [3H]spiroperidol binding declined linearly with age starting at 3 months. By 28 months, spiroperidol binding was only about 50% of the 3 month value. Dissociation constants(More)
Genotypic influences on dopaminergic-induced behaviors and striatal dopaminergic receptors were evaluated in CBA/J, C57BL/6J and BALB/cJ male mice. CBA/J mice were less behaviorally sensitive to apomorphine (stereotypic behavior) but more sensitive to haloperidol (catalepsy) than C57BL/6J and BALB/cJ mice. Striatal dopaminergic receptors, assayed by binding(More)
Decreased platelet 3H-imipramine binding density and decreased monoamine oxidase (MAO) activity have been considered as biological characteristics of several neuropsychiatric disorders, and may be related to central serotonin defects. Since serotonin system defects occur in Alzheimer's disease (AD), and decreased brain 3H-imipramine binding density, and(More)
Human caudate nucleus, putamen, substantia nigra, and nucleus accumbens were analyzed for the effects of age on dopaminergic binding sites. Decreases in the number of dopaminergic binding sites were detected with age in caudate nucleus (44 specimens from three sample groups) and substantia nigra (n = 12). In caudate nucleus, the decline in [3H]2-amino-6,(More)
The density of platelet [3H]imipramine binding sites is reported to be decreased in unipolar depression and, hence, is a putative biological marker. There is considerable evidence for a phenomenological and biological relationship of panic disorder with affective disorder. We studied platelet [3H]imipramine binding site density in unmedicated subjects with(More)
The responsiveness of male C57BL/6J mice to acute haloperidol (2.5 mg/kg, IP) was studied throughout the average adult lifespan (4, 8, 12, 21, 28 months) by effects on dopamine (DA) turnover, as estimated by DA loss after alpha-methyl-p-tyrosine (AMPT). Previously, striatal receptors for spiroperidol (a related butyrophenone) decreased progressively after 3(More)
A radioenzymatic assay is described for measuring brain catecholamines (CA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the same tissue extract. The [3H]-methylated products are differentially extracted and then acetylated by acetic anhydride, followed by thin layer chromatography in non-basic solvents. Routine sensitivity is 3-5 pg per sample. This assay(More)
Aging was associated with an increase in the density of specific binding sites for [3H]imipramine in postmortem specimens of human hypothalamus, frontal cortex, and parietal cortex. In general, [3H]imipramine binding was not affected by factors considered difficult to control in postmortem studies, i.e., time from death to autopsy and cause of death. The in(More)
Compensatory responses of striatal dopaminergic mechanisms to chronic drug treatment were tested in C57BL/6J and C57BL/6NNia male mice during the adult lifespan (5, 12, and 24 to 26 months). Chronic treatment with haloperidol (dopamine antagonist) (1.2 or 2 mg/kg/day for 21 days) induced supersensitivity in younger mice (5 and 12 months) as monitored by(More)
Clozapine and molindone administered to mice for 21 days did not elevate the density of striatal 3H-spiperone binding sites at doses clinically equivalent to 1.5 mg/kg haloperidol, which elevated binding by 29%. Thioridazine (25 mg/kg) elevated binding by 25%. It appears that clinically equivalent doses of clozapine and molindone have reduced ability to(More)