Michael T Williams

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The Morris water maze (MWM) is a test of spatial learning for rodents that relies on distal cues to navigate from start locations around the perimeter of an open swimming arena to locate a submerged escape platform. Spatial learning is assessed across repeated trials and reference memory is determined by preference for the platform area when the platform is(More)
Several disorders have been associated with mutations in Na,K-ATPase alpha isoforms (rapid-onset dystonia parkinsonism, familial hemiplegic migraine type-2), as well as reduction in Na,K-ATPase content (depression and Alzheimer's disease), thereby raising the issue of whether haploinsufficiency or altered enzymatic function contribute to disease etiology.(More)
Recent studies suggest that postmitotic neurons can reenter the cell cycle as a prelude to apoptosis after brain injury. However, most dying neurons do not pass the G1/S-phase checkpoint to resume DNA synthesis. The specific factors that trigger abortive DNA synthesis are not characterized. Here we show that the combination of hypoxia and ischemia induces(More)
BACKGROUND +/-3,4-Methylenedioxymethamphetamine (MDMA) is a recreational drug that causes cognitive deficits in humans. A rat model for learning and memory deficits has not been established, although some cognitive deficits have been reported. METHODS Male Sprague-Dawley rats were treated with MDMA (15 mg/kg x 4 doses) or saline (SAL) (n = 20/treatment(More)
BACKGROUND Both coplanar and noncoplanar polychlorinated biphenyls (PCBs) exhibit neurotoxic effects in animal studies, but individual congeners do not always produce the same effects as PCB mixtures. Humans genetically have > 60-fold differences in hepatic cytochrome P450 1A2 (CYP1A2)-uninduced basal levels and > 12-fold variability in aryl hydrocarbon(More)
Many drugs are used or abused in social contexts without understanding the ramifications of their use. In this study, we examined the effects of a newly popular drug, 5-methoxy-diisopropyltryptamine (5-MEO-DIPT; 'foxy' or 'foxy-methoxy'). Two experiments were performed. In the first, 5-MEO-DIPT (0, 10, or 20 mg/kg) was administered to rats four times on a(More)
Previously, we have shown that rats administered MDMA from postnatal (P) days 11-20 had reductions in body weight during the period of treatment and as adults they had deficits in sequential and spatial learning and memory. In the present study, to control for weight reductions, we used litters with double the number of offspring to induce growth(More)
The Na,K-ATPase is composed of multiple isoforms and the isoform distribution varies with the tissue and during development. The alpha1 isoform for example, is the major isoform in the kidney and many other tissues, while the alpha2 isoform is the predominate one in skeletal muscle. All three isoforms are found in the brain although in adult rodent brain,(More)
Plasmacortisol levels were examined to assess the stress of dogs in a county animal shelter. Groups of dogs confined in the shelter for their 1st, 2nd, or 3rd day had higher cortisol levels than did a group maintained in the shelter for more than 9 days. Dogs in the shelter for an intermediate period (Day 4-9) had intermediate levels of cortisol. The(More)
Methamphetamine (MA) has been implicated in cognitive deficits in humans after chronic use. Animal models of neurotoxic MA exposure reveal persistent damage to monoaminergic systems but few associated cognitive effects. Since questions have been raised about the typical neurotoxic dosing regimen used in animals and whether it adequately models human(More)