M L Schneider

University of Wisconsin, Madison, Madison, MS, United States

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Publications (21)67.55 Total impact

  • NeuroImage 03/2013; · 6.25 Impact Factor
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    ABSTRACT: A simple synthesis of the dopamine transporter ligand [(18)F]FECNT with high radiochemical yield and short synthesis time, suitable for routine production is reported. Reaction of 2β-carbomethoxy-3β-(4-chlorophenyl)nortropane with [(18)F]2-fluoroethyl triflate ([(18)F]FEtOTf) at room temperature for 4min provided [(18)F]FECNT in 84% decay corrected radiochemical yield. Since [(18)F]FEtOTf was prepared from [(18)F]2-fluoroethyl bromide that was isolated from its starting material, formation of unwanted side products and the amount of expensive precursor used could be greatly reduced. The overall radiochemical yields of [(18)F]FECNT were 40% (n=29) and the total synthesis time was ca. 100min. The average specific activity of [(18)F]FECNT was 377.4GBq/μmol (10.2Ci/μmol).
    Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 10/2012; 72C:128-132. · 1.09 Impact Factor
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    ABSTRACT: [F-18]Mefway was developed to provide an F-18 labeled positron emission tomography (PET) neuroligand with high affinity for the serotonin 5-HT(1A) receptor to improve the in vivo assessment of the 5-HT(1A) system. The goal of this work was to compare the in vivo kinetics of [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 in the rhesus monkey. Each of four monkeys were given bolus injections of [F-18]mefway, [C-11]WAY100635, and [F-18]MPPF and scans were acquired with a microPET P4 scanner. Arterial blood was sampled to assay parent compound throughout the time course of the PET experiment. Time activity curves were extracted in the high 5-HT(1A) binding areas of the anterior cingulate cortex (ACG), mesial temporal cortex, raphe nuclei, and insula cortex. Time activity curves were also extracted in the cerebellum, which was used as a reference region. The in vivo kinetics of the radiotracers were compared based on the nondisplaceable distribution volume (V(ND) ) and binding potential (BP(ND) ). At 30 min, the fraction of radioactivity in the plasma due to parent compound was 19%, 28%, and 29% and cleared from the arterial plasma at rates of 0.0031, 0.0078, and 0.0069 (min⁻¹) ([F-18]mefway, [F-18]MPPF, [C-11]WAY100635). The BP(ND) in the brain regions were mesial temporal cortex: 7.4 ± 0.6, 3.1 ± 0.4, 7.0 ± 1.2, ACG: 7.2 ± 1.2, 2.1 ± 0.2, 7.9 ± 1.2; raphe nuclei: 3.7 ± 0.6, 1.3 ± 0.3, 3.3 ± 0.7; and insula cortex: 4.2 ± 0.6, 1.2 ± 0.1, 4.7 ± 1.0 for [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 respectively. In the rhesus monkey, [F-18]mefway has similar in vivo kinetics to [C-11]WAY100635 and yields greater than 2-fold higher BP(ND) than [F-18]MPPF. These properties make [F-18]mefway a promising radiotracer for 5-HT(1A) assay, providing higher counting statistics and a greater dynamic range in BP(ND).
    Synapse 07/2011; 65(7):592-600. · 2.31 Impact Factor
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    ABSTRACT: [F-18]Nifene is a PET radioligand developed to image α4β2* nicotinic acetylcholine receptors (nAChR) in the brain. This work assesses the in vivo binding and imaging characteristics of [F-18]nifene in rhesus monkeys for the development of PET experiments examining nAChR binding. Dynamic PET imaging experiments with [F-18]nifene were acquired in four anesthetized Macaca mulatta (rhesus) monkeys using a microPET P4 scanner. Data acquisition was initiated with a bolus injection of 109 ± 17 MBq [F-18]nifene and the time course of the radioligand in the brain was measured for up to 120 min. For two experiments, a displacement dose of (-)nicotine (0.03 mg kg(-1) , i.v.) was given 45-60 min post injection and followed 30 min later with a second [F-18]nifene injection to measure radioligand nondisplaceable uptake. Time activity curves were extracted in the regions of the antereoventral thalamus (AVT), lateral geniculate nucleus region (LGN), frontal cortex, and the cerebellum (CB). The highest levels of [F-18]nifene uptake were observed in the AVT and LGN. Target-to-CB ratios reached maximum values of 3.3 ± 0.4 in the AVT and 3.2 ± 0.3 in the LGN 30-45 min postinjection. Significant binding of [F-18]nifene was observed in the subiculum, insula cortex, temporal cortex, cingulate gyrus, frontal cortex, striatum, and midbrain areas. The (-)nicotine displaced bound [F-18]nifene to near background levels within 15 min postdrug injection. No discernable displacement was observed in the CB, suggesting its potential as a reference region. Logan graphical estimates using the CB as a reference region yielded binding potentials of 1.6 ± 0.2 in the AVT and 1.3 ± 0.1 in the LGN. The postnicotine injection displayed uniform nondisplaceable uptake of [F-18]nifene throughout gray and white brain matter. [F-18]Nifene exhibits rapid equilibration and a moderately high target to background binding profile in the α4β2* nAChR rich regions of the brain, thus providing favorable imaging characteristics as a PET radiotracer for nAChR assay.
    Synapse 06/2011; 65(12):1309-18. · 2.31 Impact Factor
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    ABSTRACT: This study examined the striatal dopamine system integrity and associated behavior in 5- to 7-year-old rhesus monkeys born from mothers that experienced stress and/or consumed moderate levels of alcohol during pregnancy. Thirty-one young adult rhesus monkeys were derived from females randomly assigned to one of four groups: (1) control group that consumed isocaloric sucrose solution throughout gestation; (2) stress group that experienced prenatal stress (10-min removal from home cage and exposure to three random loud noise bursts, gestational days 90 through 145); (3) alcohol group that consumed alcohol (0.6 g/kg/day) throughout gestation; or (4) combined alcohol plus stress group that received both treatments. The subjects were assessed for striatal dopamine system function using positron emission tomography (PET), in which the dopamine (DA)-rich striatum was evaluated in separate scans for the trapping of [(18)F]-Fallypride (FAL) and 6-[(18)F]fluoro-m-tyrosine (FMT) to assess dopamine D2 receptor binding potential (BP) and DA synthesis via dopa decarboxylase activity, respectively. Subjects were previously assessed for non-matching-to-sample (NMS) task acquisition, with ratings of behavioral inhibition, stereotypies, and activity made after each NMS testing session. Subjects from prenatal stress conditions (Groups 2 and 4) showed an increase in the ratio of striatal dopamine D2 receptor BP and DA synthesis compared to controls (Group 1). An increase in the radiotracer distribution volume ratios (DVRs), which is used to evaluate the balance between striatal DA synthesis and receptor availability, respectively, was significantly correlated with less behavioral inhibition. The latter supports a hypothesis linking striatal function to behavioral inhibitory control.
    Neurotoxicology and Teratology 01/2004; 26(2):169-78. · 3.18 Impact Factor
  • Psychoneuroendocrinology 01/2002; 27(1). · 5.59 Impact Factor
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    M L Schneider, C F Moore, G W Kraemer
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    ABSTRACT: Although high-dose prenatal alcohol exposure is related to cognitive and behavioral impairments in children and adolescents with fetal alcohol syndrome, there is relatively little research on the effects of moderate drinking during pregnancy. We examined learning, memory, and behavior in adolescent rhesus monkeys prenatally exposed to moderate levels of alcohol, psychological stress, or both alcohol and stress. Forty adolescent rhesus monkey subjects were derived from four groups of female rhesus monkeys that (1) consumed alcohol throughout gestation; (2) experienced prenatal stress; (3) experienced prenatal stress and alcohol consumption; or (4) control group (no alcohol, no stress). The subjects were assessed for number of trials required to reach 90% criterion of correct responses on nonmatching-to-sample task (NMS), followed by trials with delays of 30, 60, or 120 sec. Ratings of behavior during testing were made after each session. Subjects exposed to moderate prenatal alcohol required significantly more trials to reach criterion on the acquisition phase of the NMS task but had no difficulty with delays. Prenatally stressed monkeys showed lower response inhibition or less behavioral restraint, whereas prenatal alcohol plus stress monkeys showed higher activity level and stereotypies compared with controls. High scores on neonatal measures of orientation (attending to novel stimuli) and motor maturity and low scores on irritability, activity, stereotypies, and impulsivity during acquisition were correlated with fewer trials to criterion on acquisition of NMS. NMS trials required to reach criterion and behavior during testing are sensitive to moderate-level prenatal alcohol exposure in monkeys. The most adverse behavioral outcomes (hyperactivity and stereotypies) were associated with prenatal alcohol plus stress, raising concerns that environmental stress might provide the context within which fetal alcohol exposure could promote adverse behavioral outcomes. These effects occurred in the absence of either facial deformities or retarded physical growth.
    Alcoholism Clinical and Experimental Research 10/2001; 25(9):1383-92. · 3.42 Impact Factor
  • M L Schneider, C F Moore, E F Becker
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    ABSTRACT: Moderate prenatal alcohol exposure can contribute to neurodevelopmental deficits in nonhuman primate offspring. The purpose of this study was to examine the effects of gestational timing of alcohol exposure on neurobehavior with a nonhuman primate model. Sixty-three rhesus monkey infants (Macaca mulatta), from four groups of females, were assessed: (1) an early alcohol-exposed group, in which mothers voluntarily consumed alcohol on gestational days 0 through 50; (2) a mid to late gestation alcohol-exposed group, in which mothers consumed an identical dose on gestation days 50 through 135; (3) a continuous-exposure group, in which mothers consumed an identical dose on days 0 through 135 or days 0 through 165; and (4) controls, in which mothers voluntarily consumed an isocaloric control solution on gestational days 0 through 50, 50 through 135, 0 through 135, or 0 through 165. Data were obtained on offspring for measures of growth and neurobehavior. There were no effects of alcohol on birthweight, gestation length, or ponderal index. Prenatal exposure to alcohol during early gestation significantly decreased scores on infant neurobehavioral tests overall in multivariate tests, after controlling for birthweight. Univariate tests showed that early gestation alcohol exposure was related to reductions in infant orientation and motor maturity. Mid- to late-gestation exposure also resulted in a reduction in motor maturity but did not affect overall neurobehavioral performance in the multivariate tests. Early-gestation alcohol exposure is as deleterious to neonatal neurobehavior as late-gestation or continuous exposure. Moreover, neurobehavior seems to be a more sensitive marker of early-gestation moderate alcohol exposure than growth parameters. Women who are attempting to become pregnant should minimize frequent social drinking, because subtle neurodevelopmental effects to the fetus may be induced before pregnancy is detected.
    Alcoholism Clinical and Experimental Research 09/2001; 25(8):1238-45. · 3.42 Impact Factor
  • M L Schneider, C F Moore, A D Roberts, O Dejesus
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    ABSTRACT: In this paper we review three prospective longitudinal studies from our laboratory examining the effects of prenatal stress on early neuro behavior, stress reactivity and learning performance in rhesus monkeys. Either a noise stressor or ACTH treatment was administered to pregnant monkeys during specific periods of pregnancy and offspring were examined repeatedly across development. In all three studies, the prenatally stressed monkeys showed reduced attention and impaired neuromotor functioning during the first month of life compared to controls from undisturbed pregnancies. When the monkeys were separated from their mothers or peers at 6-8 months of age, prenatally stressed monkeys exhibited more disturbance behavior and showed hypothalamic-pituitary-adrenal axis dysregulation. During adolescence, they exhibited impairments in learning, compared to controls.
    Stress 09/2001; 4(3):183-93. · 3.25 Impact Factor
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    ABSTRACT: Previous studies have found that stressful events during pregnancy can influence the developing fetus, resulting in attentional and neuromotor problems. This prospective study examined whether periods of vulnerability exist for neurobehavioral impairments associated with prenatal stress, using a nonhuman primate model. Twenty-eight rhesus monkey infants were born to mothers in 3 groups: (1) early gestation stress involving mild psychological stress from gestational days 45-90, (2) mid-late gestation stress from days 90-145, and (3) undisturbed controls. Infants were separated from their mothers on days 4, 9, 15, and 22 (+/- 1) postpartum for growth and neurobehavioral assessments. Results indicated that infants from the early gestation stress condition weighed less than infants from mothers stressed during mid-late gestation. Moreover, whereas both groups scored lower than controls on measures of attention and neuromotor maturity, early gestation stress was associated with more pronounced and more pervasive motor impairments than mid-late gestation stress. These results suggest sensitivity to prenatal stress effects peaks during early gestation, tapering off during mid-late gestation. Clarifying the period of greatest vulnerability to prenatal stress moves toward elucidating the underlying mechanism for prenatal stress effects and may lead to more successful intervention and/or prevention.
    Child Development 01/1999; 70(2):263-74. · 4.72 Impact Factor
  • E C Roughton, M L Schneider, L J Bromley, C L Coe
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    ABSTRACT: The purpose of this study was to investigate whether maternal endocrine activation during pregnancy would affect the neurobehavioral state of primate offspring in a manner similar to that observed in human infants from pregnancies involving maternal substance abuse or maternal stress. Twenty-two rhesus monkey (Macaca mulatta) infants were derived from females administered either adrenocorticotrophic hormone (ACTH), which increased the mother's endocrine activity, or saline solutions for 14 consecutive days during mid-pregnancy. On days 15 and 30 postpartum, infants underwent brief separations from their mothers and were videotaped for later evaluation of neurobehavioral state. Infants from mothers administered ACTH spent significantly more time in a drowsy state than did controls (p < .04), and the increased drowsiness tended to be most pronounced during the postseparation period, when acute stress was highest. In contrast, controls remained in a more active alert state (p < .03), presumably searching for their mother, a species-typical adaptive response to maternal separation. Female infants spent more time in distressed state than did males on day 15, and the proportion of time in distressed state decreased in all infants after administration of .2 ml of 24% sucrose solution. The results demonstrate that neurobehavioral state alterations are found in infants from mothers with increased endocrine activity during pregnancy. Neurobehavioral state disorganization can have an adverse impact on the human infant's concurrent and subsequent occupational performance. These findings establish the usefulness of the nonhuman primate model for advancing knowledge on early contributions to the development of human infant occupational behavior.
    The American journal of occupational therapy.: official publication of the American Occupational Therapy Association 02/1998; 52(2):90-8. · 1.70 Impact Factor
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    ABSTRACT: In this study, we assessed behavioral responses to social separation at 8 months of age and cerebrospinal fluid (CSF) concentrations of biogenic amines and metabolites at 8 and 18 months of age in 12 rhesus monkeys derived from either stressed or undisturbed pregnancies. Compared to controls from undisturbed pregnancies, prenatal stress-derived monkeys had higher concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), and 3,4-dihydroxyphenylacetic acid in CSF than controls. Norepinephrine and MHPG response to stress were both correlated between 8 and 18 months of age. There were few group differences in behavior during social separation; however, several behavioral differences between groups were found when monkeys were reunited with cage mates. Prenatally stressed monkeys spent more time clinging to their surrogates and exploring (including eating and drinking), while controls showed more locomotion and social play with their cage mates. Collectively, our findings suggest that chronic unpredictable psychological stress during pregnancy has long-lasting effects on noradrenergic and dopaminergic activity and behavior in the offspring of gestationally stressed primate mothers.
    Development and Psychopathology 02/1998; 10(3):427-40. · 4.40 Impact Factor
  • A S Clarke, M L Schneider
    Annals of the New York Academy of Sciences 02/1997; 807:490-1. · 4.38 Impact Factor
  • M. L. Schneider, A. J. Koehler
    Neurotoxicology and Teratology 01/1997; 19(3):243-244. · 3.18 Impact Factor
  • A S Clarke, D J Wittwer, D H Abbott, M L Schneider
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    ABSTRACT: The effect of stress to the pregnant mother on hormonal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and exposed to unpredictable noise during mid- to late gestation (Days 90-145 postconception), while six undisturbed pregnant mothers served as controls. Blood samples were collected from the juvenile offspring under anesthesia on four occasions and assayed for ACTH and cortisol. In a second experiment, blood samples were collected from the awake offspring under a baseline and four progressively stressful conditions. Offspring of stressed mothers showed higher ACTH and cortisol levels than control offspring at all four anesthesia samples and at a nonanesthesized home cage baseline. Prenatally stressed offspring also showed higher ACTH values in all four stress conditions. Cortisol values were similar for the two groups under the stress conditions. The disparity between the two groups in the relationship between ACTH and cortisol was greatest in the most stressful condition, suggesting regulatory differences between the two groups. These results indicate that offspring of primate mothers stressed during pregnancy show enhanced HPA axis responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on HPA axis regulation.
    Developmental Psychobiology 08/1994; 27(5):257-69. · 2.60 Impact Factor
  • C L Coe, J W Kemnitz, M L Schneider
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    ABSTRACT: Maternal and fetal/infant antibody levels were assessed across pregnancy and at birth to evaluate the prenatal transmission of IgG in the rhesus monkey. Although some antibody was evident in the fetus by midpregnancy, the marked increase in IgG occurred primarily during the last two weeks of pregnancy. This delay until the end of pregnancy would result in low antibody titers in premature infants. In contrast, when gestation length was normal, the placental transfer of IgG was resistant to both dexamethasone treatment and a prolonged period of stress during pregnancy. This resiliency occurred despite an effect of prenatal stress on other aspects of infant development, including physical growth and the fetal synthesis of complement proteins.
    Journal of Medical Primatology 08/1993; 22(5):294-300. · 1.11 Impact Factor
  • A S Clarke, M L Schneider
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    ABSTRACT: The effect of maternal psychological disturbance during pregnancy on postnatal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and briefly exposed to unpredictable noise during mid to late gestation (Days 90-145 postconception). Six undisturbed pregnant mothers served as controls. Behavioral data were later collected from the 18-month-old offspring under a baseline and four progressively stressful conditions. Social behaviors were considerably more affected by prenatal treatment than nonsocial behaviors. Prenatally stressed offspring showed more abnormal social behavior (mutual clinging) and less normal social behavior (proximity, contact) than controls. These results suggest that offspring of mothers stressed during pregnancy may show enhanced responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on behavioral reactivity.
    Developmental Psychobiology 08/1993; 26(5):293-304. · 2.60 Impact Factor
  • M L Schneider, C L Coe
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    ABSTRACT: Neuromotor responses were assessed in 90 infant squirrel monkeys born from normal and stressed pregnancies. Repeated psychological disturbance during pregnancy, evoked by disruption of the pregnant female's social relationships, significantly altered the performance of the young infant on a standardized battery of neuromotor tests. As compared with infants from undisturbed pregnancies, infants from chronically stressed pregnancies had poorer motor abilities, impaired balance reactions, and reduced postrotary nystagmus. They also had shorter attention spans and looking episodes during the administration of orientation items. In contrast, when only a single stressful period was imposed during midgestation, infants were not significantly different from control subjects. These findings indicate that sustained stress across pregnancy can have deleterious effects on fetal development, but a short period of stress, at least when restricted to midgestation, does not appear to adversely affect neuromotor responses of the young primate infant.
    Journal of Developmental & Behavioral Pediatrics 05/1993; 14(2):81-7. · 1.75 Impact Factor
  • M L Schneider
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    ABSTRACT: This prospective study investigated whether mild maternal stress during pregnancy could alter the behavioral and affective responses in rhesus monkey infants in a complex, novel environment. Twenty-four rhesus monkey infants were tested on three occasions at 6 months of age in a novel environment. Twelve infants were derived from mothers exposed to a daily 10-min mild stressor from Day 90 to Day 145 postconception, while 12 were derived from mothers undisturbed during pregnancy. Prenatally stressed infants demonstrated more disturbance behavior, and lower levels of gross motor/exploratory behavior. Moreover, half of the prenatally stressed infants showed an abnormal response, falling asleep, while none of the control infants displayed this behavior. Males exhibited more clinging to surrogates, while females spent more time in gross motor/exploratory behaviors, with prenatally stressed males tending to spend the least time in gross motor/exploratory activity.
    Developmental Psychobiology 12/1992; 25(7):529-40. · 2.60 Impact Factor
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    ABSTRACT: The influence of early rearing conditions on immunologic development was investigated in infant monkeys. Lymphocyte proliferation, natural killer cell activity, and antibody responses to tetanus vaccination were compared in 30 rhesus monkeys reared under five different conditions. Lymphocyte responses to two mitogens (concanavalin A and pokeweed) were significantly increased in infants from disturbed rearing conditions compared with control infants that had been reared in an undisturbed manner by their mothers. The largest increases occurred in nursery-reared monkeys that had been fed Similac infant formula. The nursery-reared monkeys also tended to show lower natural killer cell activity, but there were no significant differences in response to vaccination. These findings support other research indicating that psychologic and nutritional aspects of the early rearing environment may have long-lasting effects on some, but not all, immune responses in the developing infant.
    Pediatrics 10/1992; 90(3 Pt 2):505-9. · 5.12 Impact Factor