Poster Session Participants
In addition to the posters presented by the 2010 Travel Award winners, the following posters are accepted for inclusion in the 2010 poster session:
Karla Fettich, M.A.
Research Coordinator
Eating and Weight Disorders Program
The University of Chicago
Emotional impulsivity predicts treatment response in women who binge eat: an exploratory study
Karla C. Fettich, M.A., Eunice Y. Chen, Ph.D.
Although Cognitive-Behavior Therapy (CBT) is the most established treatment for eating disorders with binge eating symptomatology, about 50% of patients who receive this treatment remain unrecovered (Kotler, Bodreau & Devlin, 2003; Wilfley et al., 2002). Currently, treatment outcome for CBT can be effectively predicted only after four weeks of therapy (Grilo, Masheb & Wilson, 2006), with currently no known baseline predictors of treatment response. This study explored emotional impulsivity, respiratory amplitude and respiratory sinus arrhythmia (RSA) as baseline predictors of treatment response in a sample of 25 adult women (18 Caucasian) with binge-eating after 4 weeks of individual CBT, controlling for diagnosis, race/ethnicity, Body Mass Index (BMI) and age. Subjects who met diagnostic criteria for Bulimia Nervosa (BN; N=3) or Binge-Eating Disorder (BED; N=22) and who completed 4 weeks of individual CBT between 6/2009 and 1/2010 were selected from a pool of subjects currently enrolled in a clinical trial for the treatment of eating disorders at the University of Chicago Adult Eating and Weight Disorders Clinic. Data regarding subjects’ age (mean = 42.28 ± 11.47), BMI (mean = 36.88 ± 12.32), number of objective binges, difficulties in emotion regulation, resting respiratory amplitude and RSA were collected at pre-treatment. Subjects’ response to treatment was indicated by the percent reduction in binges at post-treatment, and was calculated using the number of objective binges reported during the Eating Disorder Examination Interview (EDE; Fairburn & Cooper, 1993) at pre- and post-treatment assessments. Subjects who dropped out before completing the 4 weeks of individual CBT and a post-treatment assessment were considered non-responders with no change in binges from pre- to post-treatment. Emotional impulsivity was assessed using the Impulse Control Difficulties subscale of the Difficulties in Emotion Regulation Scale (DERS; Gratz & Roemer, 2004). A hierarchical linear regression was conducted for the percent reduction of binges, with age, BMI, race/ethnicity (Caucasian vs. Other) and diagnosis (BED vs. non-BED) added in the first step, impulse control added in the second step, mean resting respiratory amplitude in the third step and mean resting RSA entered in the fourth step. Only the second step (impulse control) accounted for a significant portion of the variance (24.2%) in treatment response at post-treatment (b= -0.519, P= 0.026). The results suggest that when controlling for age, BMI, race/ethnicity, and diagnosis, less difficulties in impulse control predict a better treatment response in women with binge eating after 4 weeks of individual CBT. Although preliminary, these findings suggest that emotional impulsivity may be an indicator for the success of CBT in women with binge-eating disorders and could potentially help inform clinicians’ recommendations in terms of treatment choice.
Disclosure: Both authors declare that they have no conflicts of interest. Dr. Chen acknowledges the support of the National Institutes of Health (1K23MH081030-01A1). This funding agency had no role in the study design, collection, analysis or interpretation of the data, writing the poster, or the decision to submit the poster for presentation.
Keywords: CBT, Binge-Eating, Emotion Regulation, Treatment Outcome, Respiratory Sinus Arrhythmia
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Andrew Fox
Ph.D. Candidate in Psychology
University of Wisconsin
Gray-matter probability in the amygdala predicts anxious temperament and is heritable
Andrew Fox, Jonathan Oler, Steven Shelton, Terrence Oakes, Wendy Shelledy, Thomas Dyer, John Blangero, Jeffrey Rogers, Richard Davidson, Ned Kalin
In humans, childhood anxious temperament is a risk factor for the development of anxiety and depression. In monkeys, functional alterations within the amygdala are associated with the anxious temperament endophenotype. In our previous investigations of the relationship between anxious temperament and brain metabolism we accounted for variability in gray-matter probability (GMP) to ensure that our findings were related to brain function per se. In this work, we complement our previous analyses using a large sample of monkeys (n=238) to specifically investigate the relationship between anxious temperament and brain structure, as measured by GMP at each voxel. In addition, we investigated the heritability of brain structure. Because our subjects were part of a single family pedigree, we were able to investigate the heritability of these structural differences by estimating the additive polygenic component of variation using the Sequential Oligogenetic Linkage Analysis Routines (SOLAR) software package. To account for potential confounds, we co-varied for age, age2 and sex in all statistical analyses. Together these analyses seek to identify regions of the brain where brain structure is related to anxious temperament and is under genetic control. Results demonstrate GMP in the amygdala was correlated with individual differences in anxious temp-erament (p<.001, two-tailed uncorrected; voxel in amygdale t=3.67, p= 0.00015), and show substantial heritability (p<.05, FDR-corrected; peak voxel in amygdala: h2=.62, p=.000065). These findings suggest that the genetic determinants of structural variation within the amygdala may contribute to the risk to develop affective psychopathology.
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Jamie L. Hanson
Waisman Laboratory for Brain Imaging & Behavior | Child Emotion Research Lab
University of Wisconsin – Madison
Effects of Early Deprivation and Neglect on Adolescent Brain Structure and Neuropsychological Functioning
Jamie Hanson, Moo K. Chung, Brian Avants, Elizabeth A. Shirtcliff, Mary Schlaak, James Gee, Richard J. Davidson, Seth David Pollak
Research in humans has linked extreme adverse experiences early in life, such as institutional care, with both cognitive and social-emotional behavioral problems (Pollak, 2005). In particular, a large body of research in PI children has noted that there are enhanced risks for problems with concentration, attention regulation, and inhibitory control (Pollak et al., 2010; Roy, Rutter, & Pickles, 2000; Tizard & Hodges, 1978). Changes in the Prefrontal Cortex may underlie these behavioral difficulties. This study examined whether gross anatomical differences exist between children who have faced deprivation and neglect before being internationally adopted from orphanages and children who have not faced such adverse early experiences from the surrounding community matched on various demographic variables; in addition, this investigation aimed to understand how regional brain differences may be related to neuro-psychological functioning as assessed by the Cambridge Neuropsychological Test Automated Battery (CANTAB). We found poorer performance in Neuro-psychological functioning and smaller prefrontal cortical volumes for adolescents who suffered deprivation/neglect compared to typically-developing adolescents who had not suffered early adversity. Adolescents who suffered deprivation/neglect had smaller volumes in Right Medial Frontal and Left Inferior Frontal Gray Matter compared to typically-developing adolescents. These brain differences partially mediated group differences seen on CANTAB measures. These findings suggest potential neurobiological mechanisms for alterations in attention and cognitive flexibility difficulties due to early adversity.
Keywords: Early Experience, Brain Development, Adolescence
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Jennifer Knight, MD
NIMH National Research Service Award Postdoctoral Fellow, Department of Psychiatry
University of Rochester Medical Center (URMC), Rochester, New York
The Effects of Mindfulness Meditation on Perceived Stress, Loneliness, and IL-6 in Older Adults
Jennifer Knight, MD, Benjamin Chapman, PhD, Nancy Talbot, PhD, Michael Krasner, MD, Wan Tang, PhD, Xin Tu, PhD, Jan Moynihan, PhD
Increases in inflammation occur during aging, and chronic stress accelerates inflammation and its health consequences. Loneliness also plays a role in health problems associated with aging, though these mechanisms are less well understood. We conducted a randomized control trial of Mindfulness Based Stress Reduction (MBSR) for relatively healthy older adults (men and women age ≥ 65) and here test the hypotheses that MBSR reduces stress and loneliness, and that any reduction is associated with decreases in the inflammatory cytokine interleukin (IL)-6. 105 subjects randomized to the 8-week MBSR program and 102 wait-list controls (WLC) completed the Perceived Stress Scale (PSS) and the UCLA Loneliness Scale at baseline and at 3 time points following MBSR—immediately after, 3 weeks and 21 weeks following MBSR. Blood was collected for IL-6 levels at all three time points after MBSR. Prior to intervention, women reported greater perceived stress than men (p<.05). A significant reduction in PSS score was observed in women who completed MBSR (13.6 at baseline v. 11.6 following treatment, p<.001), but not in men in the treatment group (p=.77). No reductions in PSS across time were observed for subjects in the WLC group and no significant post-intervention changes in the UCLA score were observed for either gender in either group.
GEE analysis of IL-6 levels suggested a significant gender x treatment group interaction (Chi-Square=4.08, p<.05). Older adult women in the MBSR group had lower IL-6 levels following intervention compared to women in the WLC group. Using the accepted cutoff of 3.19 pg/ml to define elevated IL-6, women in the MBSR group had a lower percentage of subjects (13%) with elevated IL-6 compared to female WLC (33.9%), male MBSR (34.2%) or male WLC (28.2%) subjects following the intervention (p<.05). Change in PSS did not predict IL-6 levels in women, but was associated with lower IL-6 levels in men who participated in MBSR (Pearson coefficient = -.298, p=.07). Change in the UCLA score was also associated with lower IL-6 levels in men who participated in MBSR (Pearson coefficient = -.310, p=.06), although only PSS remained significantly associated with IL-6 (p=.06) when both were assessed in a linear regression model. These data suggest that for women, MBSR may be effective in reducing perceived stress, but not loneliness. For women, MBSR, but not perceived stress or loneliness, may be associated with lower plasma IL-6 levels. Change in perceived stress and loneliness predicted lower IL-6 levels in men who participated in MBSR, with perceived stress having a stronger direct association.
Disclosure: None
Keywords: Mindfulness meditation, stress, loneliness, IL-6, aging
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Frederick Langheim, MD
Third Year Psychiatry Research Track Resident
Department of Psychiatry
University of Wisconsin
Functional connectivity in slow wave sleep
Langheim FJ and Tononi G
We analyzed high density electroencephalographic (HD-EEG) data from 7 healthy human subjects during wakefulness and sleep using time series modeling previously applied to magnetoencephalographic data.Sixty second segments of low artifact data from periods of eyes-closed wakefulness were used for further study.To provide quasi-stationary data, an autoregressive integrative moving average (ARIMA) analysis was applied to the HD-EEG time series for model estimation within 25 time lags (~50 ms). We concluded that 40th order autoregressive, first order differencing, and first order moving average ARIMA models producedrelatively stationary residuals with respect to mean, variance, and autocorrelation structure. These residuals were used to calculate partial cross correlations between sensor time series. The zero-lag partial cross correlations, representative of synchronous cortical interactions among underlying brain regions, were in accord with previous magnetoencephalographic results.We applied the same analysis technique to data collected from the same recording sessions during rapid-eye movement (REM) sleep and slow wave sleep (SWS).While data from eyes-closed wakefulness suggested diffuse positive synchronous interactions with minimal clustering in frontal and parieto-occipital regions of each hemisphere, REM was characterized by positive synchronous interactions suggestive of a weakened wakefulness state, with a larger dominant negative synchronous cluster involving frontal midline, left frontal, left temporal and left parietal regions, and a weaker right temporal, right parietal and right occipital cluster. Conversely, SWS demonstrated strong positive proximal interactions in a large left fronto-temporal-parietal cluster which were markedly more consistent across subjects and may reflect a fundamental component of sleep.
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Jordan M. Nechvatal
PhD Student: Neurosciences
Stanford University
Unbiased Examination of the Neural Correlates of Stress Coping
Jordan M. Nechvatal, Christine L. Buckmaster, David M. Lyons
Introduction: Although the developmental effects of early-life stress are becoming increasingly well known, the effects of adult-life stress on the neural correlates of emotion regulation remain elusive. In this preliminary brain imaging study, we investigate the global effects of mild stress on adult squirrel monkeys (approx. equivalent in age to a 30-year old human) in a manner that is unbiased and unconstrained by classically predefined regions of interest.
Methods: A total of forty squirrel monkeys (Saimiri sciureus) were studied in two different living conditions. In the control condition (n = 20), monkeys were housed continuously with a familiar adult male companion. In the experimental condition (n = 20), monkeys were housed for three weeks alone and then nine weeks with an unfamiliar male. Six repeated sessions of living alone and in new pairs were conducted over the 18-month study.
Before and after the treatment conditions, whole-brain, high resolution (0.313mm² in-plane) T1weighted anatomical images were acquired on a 3T-MR scanner. Following acquisition, all images were skull-stripped, co-registered and normalized to a squirrel monkey brain template, and then segmented into both gray and white matter prior to analysis. Statistical Parametric Software (SPM) was used to detect and evaluate unbiased regional differences in white matter density both between and within each study condition in a voxel-wise, morphometric comparison.
Results: After the 18-month treatment condition, greater white-matter density was observed in ventral-medial prefrontal cortex, anterior cingulate cortex, internal capsule, and the splenium of the corpus
callosum in the experimental compared to the control animals (p<0.05). There were no significant differences in the opposite comparison (control > experimental), suggesting only the experimental group had greater white-matter density expansion as a consequence of the treatment condition. As expected, there were no differences between control and experimental brain image data before the treatment conditions.
Conclusion: In agreement with previous studies of early-life stress, this preliminary study suggests that stress is also a mediator of neuroplasticity in the adult brain. That is, coping with either early-life or adult-life mild stress-inducing events appear to increase prefrontal white-matter density in a
myelination dependent manner and independent of cortical thickness. Although future studies are needed, stress-induced neuroplasticity in adulthood may mediate more effective emotional and arousal regulatory systems in coping with future stressful events.
Disclosure: Supported by NIH 47573, NIH 77884, and a NSF Graduate Research Fellowship
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Jonathon Oler, PhD
Assistant Scientist
Lane Neuroimaging Laboratory
HealthEmotions Research Institute
Heritable and non-heritable brain metabolism during exposure to potential threat
Jonathan Oler, Andrew Fox, Steven Shelton, Terrence Oakes, Wendy Shelledy, Thomas Dyer, John Blangero, Jeffrey Rogers, Richard Davidson, Ned Kalin
This study was designed to examine the heritability of the brain’s response to acute stress. We measured glucose metabolic activity with FDG-PET in 238 young rhesus monkeys (mean=2.4 years) all belonging to a single-family multigenerational pedigree. We used the no-eye-contact (NEC) variant of the human “intruder” paradigm, thereby posing an ambiguous and relatively mild threat to the animals. Functional and structural brain data were co-registered to a standard rhesus brain template space, and a voxelwise heritability analysis was performed. To estimate the effect of additive genetic variance on observed brain activity the known pedigree relationships and individual phenotype measures were used in variance components analyses with the Sequential Oligogenic Linkage Analysis Routines (SOLAR) software package. To account for potential confounds age, age2, sex and gray matter probability at each voxel were included in the variance components model as covariates of no interest. The resulting whole-brain heritability data were corrected for multiple comparisons with a False Discovery Rate (FDR; q=0.05). Brain activity during NEC was significantly heritable in bilateral anterior hippocampal regions (right: h2=0.58, p<0.001; left: h2=0.61, p<0.001). No significantly heritable clusters were observed in the amygdala. Furthermore, heritability estimates in the dorsal prefrontal cortex (PFC) and posterior cingulate gyrus (PCC) were on the order of 0.9, and were highly significant (p<1.0e-5). These results suggest that threat-related glucose metabolism in anterior hippocampus, the PCC and the PFC reflect inherited neural responses to acute stressors.
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Chao Qi
Molecular and Cellular Pharmacology Graduate Student
University of Wisconsin
Development of a mouse model to identify the molecular underpinnings of extreme behavioral inhibition.
Roseboom PH, Nanda SA, Qi C, Lane JC, Speers JM, Kalin NH
Background: Behavioral inhibition (BI) in humans, when extreme, is a predictor of later development of psychopathologies such as anxiety disorders and depression. We have previously developed a rat model of BI using exposure to a ferret, which is a natural predator of the rat. In the present series of experiments, we extend these studies by developing a mouse model of extreme BI in response to exposure to a rat, a natural predator of the mouse. Having a mouse model will facilitate genetic approaches to understanding the origins and pathophysiology of extreme BI.
Methods: Using the previously published rat exposure test paradigm (Yang et al, Physiol Behav 81:465-73, 2004), we exposed individual adolescent and adult C57BL/6J mice for 10 min to an adult Long-Evans rat treated with amphetamine to ensure consistent behavior of the threat stimulus. Videos were used to assess the duration of BI; defined as the sum of freezing and hypervigilance, which is characterized by an absence of locomotion with accompanying minor head movements associated with sensory acquisition (sniffing and vibrissa movement). We assessed both the amount of BI in adolescents and adults as well as the stability over time in the amount of BI expressed by an individual. In a second study, we screened a group of 60 adolescent mice and identified a subgroup that stably expresses extreme high levels of BI. Amygdala tissue was obtained from these extreme animals and RNA is being extracted to be used in Affymetrix gene chip analyses.
Results: We demonstrate that adolescent mice at 30 days of age display significantly more BI (186.5 ± 31.8 sec) than when retested in adulthood at 72 days of age (82.0 ± 14.0 sec, N = 12, p < 0.001). Importantly, the amount of BI displayed by an individual in adolescence is correlated with the amount of BI displayed in adulthood (r = 0.83, N = 12, p < 0.001). In separate groups of mice, we also demonstrate that the amount of BI displayed between two exposures separated by 2 days is stable both within adolescence (r = 0.71, N = 48, p < 0.001) and adulthood (r = 0.91, N = 19, p < 0.001). Finally, gene chip analysis will be used to identify those genes that are differentially expressed in the amygdala between extreme high BI mice and mice that stably express low levels of BI.
Discussion: These findings indicate that BI in the mouse is similar to BI characterized in rats and primates such that it is expressed to a greater extent in adolescence than adulthood. Furthermore, BI in mice appears to be a trait-like characteristic that is stable across development. Molecular studies aimed at identifying genes that are differentially expressed in relation to the amount of BI an individual displays will provide insight into novel drug targets. These targets can be further implicated in mediating BI through genetic manipulations that are available through transgenic and knockout strategies. This work was supported by NIH grants MH40855 and MH43454, Meriter Hospital and UW HealthEmotions Research Institute.
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Abha Karki Rajbhandari
Neuroscience Graduate Student
University of Wisconsin
Role of norepinephrine receptors in central versus basolateral amygdala in the regulation of prepulse inhibition
Ak. Rajbhandari, S Rozzi, VP Bakshi
Prepulse inhibition (PPI) is a phenomenon by which a weak stimulus (prepulse) reduces the startle response to a subsequent stimulus (pulse), and is an operational measure of sensorimotor gating, which is deficient in several psychiatric illnesses including schizophrenia. The amygdala previously has been implicated in the regulation of PPI through dopaminergic or glutamatergic substrates. Nevertheless, the role of NE transmission within the amygdaloid complex in the modulation of PPI has not been determined. The amygdala consists of several nuclei including the basolateral complex (BLA) and the central nucleus (CeA), which are known to differ from each other anatomically and functionally, but both of which receive heavy NE innervation from the locus coeruleus (LC). Given our previous finding that stimulation of LC-originating NE-containing pathways can disrupt PPI, the present experiments tested the hypothesis that increasing NE transmission within distinct amygdala subregions might disrupt PPI. Separate groups of male Sprague-Dawley rats were prepared with chronic indwelling cannulae aimed at either the CeA or the BLA. Rats received a cocktail solution of the alpha1 receptor agonist phenylephrine plus the beta receptor agonist isoproterenol (equal parts of each agonist; 0, 3, 10, 30 µg/0.5µl/side) in a counterbalanced order over several test days. Immediately after microinfusions, rats were tested in startle chambers for measuring PPI. In separate experiments, the effects of either agonist alone were assessed. Infusion of the agonist cocktail into BLA caused a significant disruption of PPI in the absence of alterations in baseline startle, indicating a selective disruption of sensorimotor gating. No effects were seen when either agonist was administered by itself, suggesting that coincident activation of alpha1 and beta receptors may be necessary for this BLA-mediated deficit in PPI. In contrast, infusion of the NE receptor agonist cocktail into CeA had no effect on PPI, although it did tend to reduce baseline startle responses. Intra-CeA infusion of the dopamine agonist quinpirole, however, produced a trend towards a disruption in PPI in the same rats that failed to show NE agonist-mediated deficits. This trend was consistent with previous studies indicating that dopamine agonists in the amygdala can disrupt PPI (Swerdlow NR et al 1992). Taken together, these findings support a role for NE transmission within the amygdala in the regulation of PPI, but suggest that CeA and BLA are differentially involved, with alpha1 and beta receptor stimulation selectively within BLA causing deficits in sensorimotor gating.
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Helen Weng
Ph.D. Candidate in Psychology
University of Wisconsin
Can Compassion Be Trained? Behavioral and Biological Evidence
Weng, HY, Fox, AS, Shackman, AJ, Vack, NJ, Kirkland Caldwell, JZ, Stodola, DE,
Olson, M, Rogers, GM, Davidson, RJ
Individuals may respond to the suffering of others by feeling personal distress or compassion (Davis, 1980). Helping professionals such as medical doctors and psychotherapists may experience excess personal distress, which can lead to compassion fatigue or burnout (Figley, 2002). Contemplative traditions posit that
compassion is a skill that can be trained. We hypothesize that compassion meditation may help individuals regulate personal distress, promote empathic concern, and increase prosocial behavior. This hypothesis was investigated by examining neural and visual processing of social suffering before and after 2 weeks of compassion meditation training vs. cognitive reappraisal. Participants were randomized to compassion (n=28) or reappraisal training (n=28) groups. In the fMRI task, participants viewed social pictures (Negative, Neutral), and were given an instruction (to use their respective Training, or Attend) before and after training (Time 1, Time 2). Ratings of compassion were measured during the training period, and prosocial behavior was tested at Time 2. Compassion training was found to modulate left amygdala activity (Group x Time x Instruction x Valence interaction, F=8.55, p=0.005, uncorrected), a region heavily implicated in emotion processing. As hypothesized, the compassion group redistributed more wealth than the reappraisal group in a novel economic prosocial task (Mann‐Whitney U=136, p=0.45). Closer examination of amygdala activity showed that at Time 1, Training amygdala activity was greater in compassion vs. reappraisal (p<0.05). This may be due to increased visual fixation on emotional information, and current eye‐tracking data analysis will inform this hypothesis. At Time 2, compassion group amygdala activity decreased (p<0.01). Intriguingly, compassion amygdala activity at Time 2 actually predicted the amount of wealth redistributed (rs=‐0.44, p=0.05), supporting the hypothesis that neural changes due to compassion training are related to changes in prosocial behavior. Although participants reported increased feelings of compassion pre‐ to post‐meditation for all people (all p’s<0.001), these ratings did not relate to amygdala activity or redistribution behavior. These results suggest that down‐regulation of amygdala due to compassion training (which may reflect decreases in personal distress) promotes prosocial behavior. Compassion training may benefit helping professionals by decreasing personal distress and enhancing helping behavior.
Disclosure The authors report no conflicts of interest.
Keywords: Empathy, Compassion, Prosocial Behavior, Meditation, Emotion Regulation
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Dustin Wooten
Medical Physics Graduate Student
University of Wisconsin-Madison
Characteristics of a novel PET Biomarker for studying the role of serotonin 5-HT1A receptors in neurodevelopment.
DW Wooten, AT Hillmer, J Moraino, JW Engle, T Barnhart, D Murali, J Mukherjee, ML Schneider, RJ Davidson, NH Kalin, BT Christian
Introduction: The 5-HT1A receptor system has been shown to play an important role in many aspects of cognitive and emotional processing. Disruptions in this system during the course of neurodevelopment are implicated in a wide variety of neuropsychiatric diseases. The goal of this work is to investigate the in vivo imaging characteristics of a novel PET 5-HT1A serotonin neuroligand, [18F]MEFWAY (MEF), as part of our research program for studying the effects of stress on neurodevelopment in the nonhuman primate model. The imaging properties of MEF were compared with two other PET 5-HT1A radiotracers, [11C]WAY100635 and [18F]MPPF. The intersubject variability of MEF was measured in a group of rhesus monkeys.
Methods: Dynamic PET studies were acquired in each of three rhesus monkeys that were given bolus injections of MEF, WAY and MPPF. Data were acquired with a microPET P4 scanner and arterial blood draws were taken to assay native compound. Time activity curves were extracted in the high 5-HT1A binding areas of the cingulate (CG) and mesial temporal cortex (MTC) and the cerebellum (CB). In a separate group of animals (n=9) regional variability of MEF binding was measured using bolus injection studies and 90 minutes of scanning. Specific 5-HT1A binding of MEF was determined using the Logan DVR method.
Results: The time course of native compound in the plasma was comparable for all tracers with 16%, 15%, 17% (x10-4) (MEF, MPPF, WAY) present at 40 minutes after injection. Bound to free (cerebellar) ratios were found to be 12, 2.8, and 13 (MEF, MPPF, WAY) in the CG and 14, 5.2, and 14 (MEF, MPPF, WAY) in the MTC, revealing very similar in vivo kinetics of MEF and WAY. From the MEF data in the separate group (n=9), there was a coefficient of variation of 22% (BPND = 5.0 ± 1.1) in the CG and 13% (BPND = 6.2 ± 0.8) in the MTC. Based upon the PET images of MEF, there was no presence of radiolabel in the skull due to defluorination of the compound.
Conclusions: The in vivo behavior of MEF and WAY was very similar in both the plasma and brain tissue space, with the counting statistics considerable higher for MEF due to the 18F radiolabel. Although the target to back ground binding for MPPF was considerably lower than MEF, the time needed for equilibration is less, suggesting that scanning durations of approximately 45 minutes will be adequate. The variability of 5-HT1A binding with MEF in the high receptor density regions of the brain is within the same range as that found in humans and with other neuroreceptor systems using PET methods. [18F]MEFWAY will serve as a valuable tool for studying the 5-HT1A system in rhesus models of neurodevelopmental disease.
Role of norepinephrine receptors in central versus basolateral amygdala in the regulation of prepulse inhibition
Ak. Rajbhandari, S Rozzi, VP Bakshi