David O'Mara

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Prior studies demonstrate a critical role for mesolimbic dopamine systems, particularly nucleus accumbens, in the mediation of fixed interval (FI) schedule-controlled behavior and an enhancement of nucleus accumbens dopamine activity as a mechanism of chronic postweaning lead (Pb)-induced increases in Fl response rates. Since dorsomedial striatum, like(More)
An important example of bilateral symmetry in nature is the approximate bilateral symmetry exhibited by humans. Detecting and measuring bilateral symmetry in medical images should provide beneets in a clinical environment. This paper presents a method for detecting the dominant plane of bilateral symmetry in an image of arbitrary dimension and subsequently(More)
To examine the assertion that changes in nucleus accumbens (NAC) dopamine (DA) activity serve as a mechanism of lead (Pb)-induced disruption of fixed interval (FI) schedule-controlled behavior, the effects of intra-NAC administration of the irreversible DA antagonist EEDQ (N-ethoxycarbonyl-2-ethoxy-1,2-dihyroquinoline) and of dopamine itself on FI(More)
Prior studies have reported that Pb exposure results in enhanced sensitivity to both D1 and D2 dopamine agonists as indicated by left shifts of the dose-effect functions for the discrimination of these agonists from saline in drug discrimination procedures (Cory-Slechta and Widzowski, 1991). To further determine mechanisms of such Pb-induced changes in(More)
Exposures to even very low levels of lead (Pb) alter behavioral and neurochemical functions. The current study was based on the hypothesis that excess synaptic dopamine (DA) availability may contribute to such disturbances and that the mesolimbic DA projection is more sensitive than the nigrostriatal system to Pb-induced DA-based alterations. In vivo(More)
Despite high overall immunization coverage levels among U.S. preschool children, areas of underimmunization, called pockets of need, remain. These areas, which pose both a personal health and a public health risk, are typically poor, crowded, urban areas in which barriers to immunization are difficult to overcome and health care resources are limited. The(More)
During the period September 1981 to August 1985, we investigated every reported case of measles in Oklahoma to confirm the diagnosis, to determine the source, and to identify contacts to prevent spread of the disease. During this time, 33 serologically and/or epidemiologically confirmed cases were investigated. Nine (27%) persons acquired measles in a(More)
To further ascertain the relative contributions of nucleus accumbens (NAC) and dorsomedial striatum (DS) to cognitive behaviors, the comparative effects in rats of MK-801 microinjections into these regions on a multiple schedule of repeated learning (RL) and performance (P) were examined. The RL component required learning of a new three-member response(More)