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Sillay K.A.,University of Wisconsin - Madison | Chen J.C.,University of Wisconsin - Madison | Chen J.C.,Medical College of Wisconsin | Montgomery E.B.,University of Wisconsin - Madison | And 2 more authors.

Objective: Deep brain stimulation technology now allows a choice between constant current and constant voltage stimulation, yet clinical trials comparing the two are lacking. Impedance instability would theoretically favor constant current stimulation; however, few publications address this with long-term follow-up. In this report, we review our series for impedance change and discuss our findings and their implications for future study design. Materials and Methods: A retrospective chart review was performed of all consecutive patients seen in the outpatient clinic for deep brain stimulation adjustments at the University of Wisconsin-Madison from February 2006 to May 2007. The following data were extracted: Quadrapolar contact selection, frequency, voltage, pulse width, and measured impedance at the therapeutic parameters. Patients were selected if consecutive measurements of therapeutic impedances for the same patient were performed with the same frequency, pulse width, voltage, and configuration of active contacts. Results: A total of 63 patients with 110 electrodes had 301 documented programming visits. From these, 16 patients had 20 consecutive measurements with unchanged parameters in 19 electrodes at a median interval of 68 days and median follow-up of 549 days after implantation. No significant intra-patient intra-electrode therapeutic impedance variability was observed in this study (SD = 105.3 ω, paired t-test, p = 0.312). In contrast, marked inter-patient variability in impedance was noted. This variability could not be explained by stimulation target, measurement interval, time since implantation, monopolar vs. bipolar stimulation, stimulation voltage, or stimulation frequency. Conclusions: No significant change in the same electrode therapeutic impedance was identified. Given the assumption that stimulation current is the critical parameter influencing clinical outcomes, these findings would not disadvantage constant voltage stimulation. However, inter-patient variability suggests a possible advantage for constant current stimulation when generalizing experience and comparisons over multiple patients. Further study of the relationship of stimulation efficacy to stimulation mode and impedance change is warranted. © 2010 International Neuromodulation Society. Source

Gill K.E.,One Medical Center Drive | Pierre P.J.,One Medical Center Drive | Pierre P.J.,National Primate Research Center | Daunais J.,One Medical Center Drive | And 6 more authors.

Despite the widespread use of stimulant medications for the treatment of attention deficit hyperactivity disorder, few studies have addressed their long-term effects on the developing brain or susceptibility to drug use in adolescence. Here, we determined the effects of chronic methylphenidate (MPH) treatment on brain dopamine (DA) systems, developmental milestones, and later vulnerability to substance abuse in juvenile nonhuman primates. Male rhesus monkeys (approximately 30 months old) were treated daily with either a sustained release formulation of MPH or placebo (N8 per group). Doses were titrated to achieve initial drug blood serum levels within the therapeutic range in children and adjusted throughout the study to maintain target levels. Growth, including measures of crown-rump length and weight, was assessed before and after 1 year of treatment and after 3-5 months washout. In addition, positron emission tomography scans were performed to quantify binding availability of D2/D3 receptors and dopamine transporters (DATs). Distribution volume ratios were calculated to quantify binding of 18 Ffluoroclebopride (DA D2/D3) and 18 F-()-N-(4-fluorobenzyl)-2β-propanoyl-3β-(4-chlorophenyl)tropane (DAT). Chronic MPH did not differentially alter the course of weight gain or other measures of growth, nor did it influence DAT or D2/D3 receptor availability after 1 year of treatment. However, after washout, the D2/D3 receptor availability of MPH-treated animals did not continue to decline at the same rate as control animals. Acquisition of intravenous cocaine self-administration was examined by first substituting saline for food reinforcement and then cocaine doses (0.001-0.1 mg/kg per injection) in ascending order. Each dose was available for at least five consecutive sessions. The lowest dose of cocaine that maintained response rates significantly higher than saline-contingent rates was operationally defined as acquisition of cocaine reinforcement. There were no differences in rates of acquisition, overall response rates, or cocaine intake as a function of cocaine dose between groups. In an animal model that closely mimics human development; chronic treatment with therapeutic doses of sustained release MPH did not have a significant influence on the regulation of DATs or D2/D3 receptors, or on standard measures of growth. Furthermore, this treatment regimen and subsequent drug washout did not have an impact on vulnerability to cocaine abuse.© 2012 American College of Neuropsychopharmacology. Source

Choi H.,Gwangju Institute of Science and Technology | Jin S.,Gwangju Institute of Science and Technology | Kwon J.T.,Gwangju Institute of Science and Technology | Kim J.,Gwangju Institute of Science and Technology | And 6 more authors.

The members of the ADAM (a disintegrin and metalloprotease) family are membraneanchored multi-domain proteins that play prominent roles in male reproduction. ADAM2, which was one of the first identified ADAMs, is the best studied ADAM in reproduction. In the male germ cells of mice, ADAM2 and other ADAMs form complexes that contribute to sperm-sperm adhesion, sperm-egg interactions, and the migration of sperm in the female reproductive tract. Here, we generated specific antibodies against mouse and human ADAM2, and investigated various features of ADAM2 in mice, monkeys and humans. We found that the cytoplasmic domain of ADAM2 might enable the differential association of this protein with other ADAMs in mice. Western blot analysis with the anti-human ADAM2 antibodies showed that ADAM2 is present in the testis and sperm of monkeys. Monkey ADAM2 was found to associate with chaperone proteins in testis. In humans, we identified ADAM2 as a 100-kDa protein in the testis, but failed to detect it in sperm. This is surprising given the results in mice and monkeys, but it is consistent with the failure of ADAM2 identification in the previous proteomic analyses of human sperm. These findings suggest that the reproductive functions of ADAM2 differ between humans and mice. Our protein analysis showed the presence of potential ADAM2 complexes involving yet-unknown proteins in human testis. Taken together, our results provide new information regarding the characteristics of ADAM2 in mammalian species, including humans. © 2016 Choi et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Diaz-Munoz S.L.,New York University | Bales K.L.,New York University | Bales K.L.,National Primate Research Center
American Journal of Primatology

This paper is the introduction to a special issue on "'Monogamy' in Primates: Variability, Trends, and Synthesis." The term "monogamy" has undergone redefinition over the years, and is now generally understood to refer to certain social characteristics rather than to genetic monogamy. However, even the term "social monogamy" is used loosely to refer to species which exhibit a spectrum of social structures, mating patterns, and breeding systems. Papers in this volume address key issues including whether or not our definitions of monogamy should change in order to better represent the social and mating behaviors that characterize wild primates; whether or not primate groups traditionally considered monogamous are actually so (by any definition); ways in which captive studies can contribute to our understanding of monogamy; and what selective pressures might have driven the evolution of monogamous and non-monogamous single female breeding systems. Am. J. Primatol. 78:283-287, 2016. © 2016 Wiley Periodicals, Inc. Source

Terleph T.A.,Sacred Heart University at Connecticut | Malaivijitnond S.,National Primate Research Center | Malaivijitnond S.,Chulalongkorn University | Reichard U.H.,Southern Illinois University Carbondale
American Journal of Primatology

Gibbons (family Hylobatidae) produce loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. The female's great call, the most conspicuous phrase of the gibbon vocal repertoire, functions primarily to mediate territorial defense. Despite the fact that lar gibbons (Hylobates lar) are the most widely distributed and well researched hylobatid species and produce a rich vocal repertoire, the individual-specificity of their great calls has not previously been quantified. In addition, spectral and temporal features of notes occurring at specific locations within the lar great call have not been described. Here we provide such a description, and test the hypothesis that great calls are statistically discriminable between a large sample of individual callers. We compared recordings of great calls from 14 wild lar females in Khao Yai National Park, Thailand. Our analyses of principal components derived from spectral and temporal measures, as well as spectrograms from the entire great call, indicate that acoustic variation is sufficient to allow identification of individual callers (83.5% discriminability based on principal components, and inter-individual call variation exceeding intra-individual variation in overall spectrogram). These vocalizations potentially allow individual recognition of animals. © 2015 Wiley Periodicals, Inc.. Source

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