1
|
Charbonneau JA, Santistevan AC, Raven EP, Bennett JL, Russ BE, Bliss-Moreau E. Evolutionarily conserved neural responses to affective touch in monkeys transcend consciousness and change with age. Proc Natl Acad Sci U S A 2024; 121:e2322157121. [PMID: 38648473 PMCID: PMC11067024 DOI: 10.1073/pnas.2322157121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/05/2024] [Indexed: 04/25/2024] Open
Abstract
Affective touch-a slow, gentle, and pleasant form of touch-activates a different neural network than which is activated during discriminative touch in humans. Affective touch perception is enabled by specialized low-threshold mechanoreceptors in the skin with unmyelinated fibers called C tactile (CT) afferents. These CT afferents are conserved across mammalian species, including macaque monkeys. However, it is unknown whether the neural representation of affective touch is the same across species and whether affective touch's capacity to activate the hubs of the brain that compute socioaffective information requires conscious perception. Here, we used functional MRI to assess the preferential activation of neural hubs by slow (affective) vs. fast (discriminative) touch in anesthetized rhesus monkeys (Macaca mulatta). The insula, anterior cingulate cortex (ACC), amygdala, and secondary somatosensory cortex were all significantly more active during slow touch relative to fast touch, suggesting homologous activation of the interoceptive-allostatic network across primate species during affective touch. Further, we found that neural responses to affective vs. discriminative touch in the insula and ACC (the primary cortical hubs for interoceptive processing) changed significantly with age. Insula and ACC in younger animals differentiated between slow and fast touch, while activity was comparable between conditions for aged monkeys (equivalent to >70 y in humans). These results, together with prior studies establishing conserved peripheral nervous system mechanisms of affective touch transduction, suggest that neural responses to affective touch are evolutionarily conserved in monkeys, significantly impacted in old age, and do not necessitate conscious experience of touch.
Collapse
Affiliation(s)
- Joey A. Charbonneau
- Neuroscience Graduate Program, University of California, Davis, CA95616
- Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, CA95616
| | - Anthony C. Santistevan
- Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, CA95616
- Department of Psychology, University of California, Davis, CA95616
| | - Erika P. Raven
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY10016
| | - Jeffrey L. Bennett
- Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, CA95616
- Department of Psychology, University of California, Davis, CA95616
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, Sacramento, CA95817
- The Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Sacramento, CA95817
| | - Brian E. Russ
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY10962
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY10029
- Department of Psychiatry, New York University Langone, New York, NY10016
| | - Eliza Bliss-Moreau
- Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, CA95616
- Department of Psychology, University of California, Davis, CA95616
| |
Collapse
|
2
|
Santistevan AC, Fiske O, Moadab G, Charbonneau JA, Isaacowitz DM, Bliss-Moreau E. See no evil: Attentional bias toward threat is diminished in aged monkeys. Emotion 2024; 24:303-315. [PMID: 37603001 PMCID: PMC10879459 DOI: 10.1037/emo0001276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Prior evidence demonstrates that relative to younger adults, older human adults exhibit attentional biases toward positive and/or away from negative socioaffective stimuli (i.e., the age-related positivity effect). Whether or not the effect is phylogenetically conserved is currently unknown and its biopsychosocial origins are debated. To address this gap, we evaluated how visual processing of socioaffective stimuli differs in aged, compared to middle-aged, rhesus monkeys (Macaca mulatta) using eye tracking in two experimental designs that are directly comparable to those historically used for evaluating attentional biases in humans. Results of our study demonstrate that while younger rhesus possesses robust attentional biases toward threatening pictures of conspecifics' faces, aged animals evidence no such bias. Critically, these biases emerged only when threatening faces were paired with neutral and not ostensibly "positive" faces, suggesting social context modifies the effect. Results of our study suggest that the evolutionarily shared mechanisms drive age-related decline in visual biases toward negative stimuli in aging across primate species. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Collapse
Affiliation(s)
- Anthony C. Santistevan
- Department of Psychology, University of California, Davis
- California National Primate Research Center, University of California, Davis
| | - Olivia Fiske
- Department of Psychology, University of California, Davis
- California National Primate Research Center, University of California, Davis
| | - Gilda Moadab
- Department of Psychology, University of California, Davis
- California National Primate Research Center, University of California, Davis
| | - Joey A. Charbonneau
- California National Primate Research Center, University of California, Davis
- Neuroscience Graduate Group, University of California, Davis
| | | | - Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis
- California National Primate Research Center, University of California, Davis
| |
Collapse
|
3
|
Santistevan AC, Moadab G, Fiske O, Nord CM, Isaacowitz DM, Bliss-Moreau E. Cardiac psychophysiological tuning to socioaffective content is disrupted in aged rhesus monkeys (Macaca mulatta). Psychophysiology 2024; 61:e14410. [PMID: 37850617 PMCID: PMC10842326 DOI: 10.1111/psyp.14410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 03/31/2023] [Accepted: 04/30/2023] [Indexed: 10/19/2023]
Abstract
Aging ushers in numerous disruptions to autonomic nervous system (ANS) function. Although the effects of aging on ANS function at rest are well characterized, there is surprising variation in reports of age-related differences in ANS reactivity to psychosocial stressors, with some reports of decreases and other reports of increases in reactivity with age. The sources of variation in age-related differences are largely unknown. Nonhuman primate models of socioaffective aging may help to uncover sources of this variation as nonhuman primates share key features of human ANS structure and function and researchers have precise control over the environments in which they age. In this report, we assess how response patterns to dynamic socioaffective stimuli in the parasympathetic and sympathetic branches of rhesus monkeys (Macaca mulatta) ANS differ in aged compared to middle-aged monkeys. We find that respiratory sinus arrhythmia, a cardiac indicator of activity in the parasympathetic branch of the ANS, exhibits age-related disruptions in responding while monkeys view videos of conspecifics. This suggests that there are evolutionarily conserved mechanisms responsible for the patterns of affective aging observed in humans and that aged rhesus monkeys are a robust translational model for human affective aging.
Collapse
Affiliation(s)
- Anthony C Santistevan
- Department of Psychology, University of California, Davis, Davis, California, USA
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Gilda Moadab
- Department of Psychology, University of California, Davis, Davis, California, USA
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Olivia Fiske
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Christina M Nord
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Derek M Isaacowitz
- Department of Psychology, Northeastern University, Boston, Massachusetts, USA
| | - Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis, Davis, California, USA
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| |
Collapse
|
4
|
Bulkeley E, Santistevan AC, Varner D, Meyers S. Imaging flow cytometry to characterize the relationship between abnormal sperm morphologies and reactive oxygen species in stallion sperm. Reprod Domest Anim 2023; 58:10-19. [PMID: 36059066 DOI: 10.1111/rda.14241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/31/2022] [Indexed: 01/07/2023]
Abstract
Low levels of intracellular reactive oxygen species (ROS) are essential for normal sperm function and are produced by sperm mitochondria as a byproduct of metabolism, but in excess, ROS can cause catastrophic cellular damage and has been correlated with infertility, poor sperm motility and abnormal morphology in humans. Stallion sperm motility is fueled predominantly by oxidative phosphorylation-produced ATP, requiring high basal rates of mitochondrial function. Consequently, whether elevated ROS production by stallion sperm is an indicator of dysfunctional or highly motile cells has been debated by researchers over the last decade. The objective of this study was to evaluate the relationship between various sperm morphologies and ROS production in fresh and cooled stallion semen by employing the novel method of imaging flow cytometry for stallion semen assessment. For evaluation of fresh semen, single ejaculates (n = 5) were collected from four resident stallions at the University of California, Davis. For the evaluation of 24-h cool-stored semen, single ejaculates were collected from stallions at Texas A&M University (n = 5) and shipped to the University of California, Davis overnight for evaluation. Ejaculate volume, sperm concentration and motility parameters were recorded. Samples were co-stained for viability and ROS detection with SytoxGreen™ and dihydroethidium (DHE), respectively, and evaluated with the Amnis® ImageStream® system (Luminex Corporation). Antimycin, an electron transport chain inhibitor that triggers ROS production (1 μM), was used as a positive control for DHE, while dead cells (2× snap frozen in liquid nitrogen) served as a positive control for SytoxGreen™. Unstained samples were also evaluated as controls. Imaging flow cytometric analysis was performed with the ideas® software (Luminex Corporation). Evaluated morphologies included abnormal head (AH), abnormal midpiece (AM), abnormal tail (AT), proximal cytoplasmic droplet (PD), or distal cytoplasmic droplet (DD), and morphologically normal (MN) cells. For fresh semen, an additional abnormality, coiled tail and midpiece (CTM) was assessed; 24-h cool-stored semen did not contain enough viable CTM cells for analysis. Only cells with obvious, single abnormalities were selected for the first portion of analysis to minimize subjectivity. Mixed effects modelling was used to evaluate the relationship between each morphologic classification and the corresponding DHE fluorescence intensity. Compared to the MN population, ROS production was significantly higher in viable cells with AH, PD and AM (p < .0001) in both fresh and cooled semen. CTM cells had significantly higher levels of ROS production compared to MN cells in fresh semen (p < .0001). There was no significant difference in ROS levels between MN cells and AT and DD cells in either fresh or cooled semen (p > .05). These results suggest that ROS generation is indicative of abnormal cell morphology and function and confirm that imaging flow cytometry is a valuable tool for the assessment of stallion semen.
Collapse
Affiliation(s)
- Evelyn Bulkeley
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Anthony C Santistevan
- Department of Psychology, College of Letters and Sciences, University of California, Davis, California, USA
| | - Dickson Varner
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, Texas, USA
| | - Stuart Meyers
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, California, USA
| |
Collapse
|
5
|
Bulkeley EA, Foutouhi A, Wigney K, Santistevan AC, Collins C, McNabb B, Meyers S. Effects from disruption of mitochondrial electron transport chain function on bull sperm motility. Theriogenology 2021; 176:63-72. [PMID: 34571399 DOI: 10.1016/j.theriogenology.2021.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/09/2021] [Accepted: 09/16/2021] [Indexed: 11/17/2022]
Abstract
Sperm mitochondrial function is essential for normal physiology and fertility, but the importance of mitochondrial activity to support specific sperm functions, such as motility, varies between species. It was previously believed that mitochondrial function was not necessary for bull sperm motility [1]; however, this theory is contradicted by recently reported findings that the upper fraction of bull sperm swim-up preparations had both high motility and elevated mitochondrial oxygen consumption rates [2]. The objective of this study was to investigate the relationship between mitochondrial function and motility in bull sperm. We hypothesized that sperm motility would be positively correlated with mitochondrial oxygen consumption (MITOX) but unaffected by pharmacological inhibition of electron transport chain (ETC) activity. This was accomplished by monitoring both mitochondrial oxygen consumption and motility parameters in the presence of mitochondrial effector drug treatments. Duplicate ejaculates were collected by electroejaculation from Black Angus bulls (n = 4). Oxygen consumption, as % air saturation (pO2; oxygen partial pressure), over time was monitored in the presence of 5 drug treatments: vehicle control, FCCP, Antimycin (ANTI), Oligomycin (Oligo), and FCCP + Oligomycin (FCCP + OLIGO). Duplicate aliquots were prepared for concurrent motility assessment by computer-assisted sperm analysis (CASA) at 6 and 30 min post-treatment (t6 and t30). The impact of treatments on pO2 (in % air saturation) over time were assessed by generalized linear mixed effects modeling (GLMM) which was also used to test for differences in average motility across treatment conditions and time points (t6 and t30). Pearson product-moment correlation was used to investigate relationships between oxygen consumption and motility parameters. Overall, pO2 differed over time between treatment conditions (p < 0.0001). When compared to the vehicle treatment, ANTI and OLIGO significantly inhibited oxygen consumption (p < 0.05, adjusted), and FCCP stimulated a marked increase in oxygen consumption. No significant differences in motility over time were observed between treatments, so comparison of motility parameters between treatment conditions was performed with pooled timepoints. Motility parameters were only observed to differ significantly from the vehicle with ANTI Treatment, for which significant decreases in numerous parameters, including total motility (p = 0.007), progressive motility (p = 0.01), DAP (p = 0.01), VAP (p = 0.01) and VSL (p = 0.02) were identified. For the vehicle treatment, correlational analysis did not reveal any significant correlations between pO2 and any motility parameters at t6; however, several significant correlations were identified at t30. Mean pO2 was negatively correlated with local motility (p < 0.01) and positively correlated with DCL, DAP, and VCL (p < 0.05). Results from this study suggest that bovine sperm motility is impacted by mitochondrial functionality, with ETC inhibition by ANTI causing significant reduction in motility parameters. This study also demonstrates the use of a new technology for the assessment of bovine sperm mitochondrial function. This modality for evaluation of bull sperm mitochondrial function will inform future efforts to understand bull sperm function and fertility and aid investigations into toxicological agents.
Collapse
Affiliation(s)
- Evelyn A Bulkeley
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, United States
| | - Azarene Foutouhi
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, United States
| | - Kayla Wigney
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, United States
| | | | - Christine Collins
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, United States
| | - Bret McNabb
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, United States
| | - Stuart Meyers
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, United States.
| |
Collapse
|
6
|
Bliss-Moreau E, Santistevan AC, Bennett J, Moadab G, Amaral DG. Anterior Cingulate Cortex Ablation Disrupts Affective Vigor and Vigilance. J Neurosci 2021; 41:8075-8087. [PMID: 34380767 PMCID: PMC8460142 DOI: 10.1523/jneurosci.0673-21.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 11/21/2022] Open
Abstract
Despite many observations of anterior cingulate cortex (ACC) activity related to cognition and affect in humans and nonhuman animals, little is known about the causal role of the ACC in psychological processes. Here, we investigate the causal role of the ACC in affective responding to threat in rhesus monkeys (Macaca mulatta), a species with an ACC largely homologous to humans in structure and connectivity. Male adult monkeys received bilateral ibotenate axon-sparing lesions to the ACC (sulcus and gyrus of areas 24, 32, and 25) and were tested in two classic tasks of monkey threat processing: the human intruder and object responsiveness tasks. Monkeys with ACC lesions did not significantly differ from controls in their overall mean reactivity toward threatening or novel stimuli. However, while control monkeys maintained their reactivity across test days, monkeys with ACC lesions reduced their reactivity toward stimuli as days advanced. Critically, this attenuated reactivity was found even when the stimuli presented each day were novel, suggesting that ACC lesions did not simply cause accelerated adaptation to stimuli as they became less novel over repeated presentations. Rather, these results imply that the primate ACC is necessary for maintaining appropriate affective responses toward potentially harmful and/or novel stimuli. These findings therefore have implications for mood disorders in which responding to threat and novelty is disrupted.SIGNIFICANCE STATEMENT Decades of research in humans and nonhuman animals have investigated the role of the anterior cingulate cortex in a huge number and variety of psychological processes spanning cognition and affect, as well as in psychological and neurologic diseases. The structure is broadly implicated in psychological processes and mental and neurologic health, yet its causal role in these processes has largely gone untested, particularly in primates. Here we demonstrate that when anterior cingulate cortex is completely eliminated, rhesus monkeys are initially responsive to threats, but these responses attenuate rather than persist, resembling a pattern of behavior commonly seen in patients diagnosed with mood disorders.
Collapse
Affiliation(s)
- Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis, Davis, California 95616
- California National Primate Research Center, University of California, Davis, Davis, California 95616
| | - Anthony C Santistevan
- Department of Psychology, University of California, Davis, Davis, California 95616
- California National Primate Research Center, University of California, Davis, Davis, California 95616
| | - Jeffrey Bennett
- Department of Psychology, University of California, Davis, Davis, California 95616
- California National Primate Research Center, University of California, Davis, Davis, California 95616
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California 95817
- The MIND Institute, School of Medicine, University of California, Davis, Davis, California 95817
| | - Gilda Moadab
- Department of Psychology, University of California, Davis, Davis, California 95616
- California National Primate Research Center, University of California, Davis, Davis, California 95616
| | - David G Amaral
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California 95817
- The MIND Institute, School of Medicine, University of California, Davis, Davis, California 95817
| |
Collapse
|
7
|
Bliss-Moreau E, Santistevan AC, Beisner B, Moadab G, Vandeleest J, McCowan B. Monkey’s Social Roles Predict Their Affective Reactivity. Affec Sci 2021; 2:230-240. [PMID: 36042947 PMCID: PMC9382983 DOI: 10.1007/s42761-021-00048-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 04/21/2021] [Indexed: 10/29/2022]
Abstract
AbstractAccumulating evidence demonstrates that the number of social connections an individual has predicts health and wellbeing outcomes in people and nonhuman animals. In this report, we investigate the relationship between features of an individuals’ role within his social network and affective reactivity to ostensibly threatening stimuli, using a highly translatable animal model — rhesus monkeys. Features of the social network were quantified via observations of one large (0.5 acre) cage that included 83 adult monkeys. The affective reactivity profiles of twenty adult male monkeys were subsequently evaluated in two classic laboratory-based tasks of negative affective reactivity (human intruder and object responsiveness). Rhesus monkeys who had greater social status, characterized by age, higher rank, more close social partners, and who themselves have more close social partners, and who played a more central social role in their affiliative network were less reactive on both tasks. While links between social roles and social status and psychological processes have been demonstrated, these data provide new insights about the link between social status and affective processes in a tractable animal model of human health and disease.
Collapse
|
8
|
Abstract
Over the past century, great debate has ensued regarding the fundamental properties of emotions. The idea that 2 properties-valence and arousal-are critical for emotion and psychologically irreducible has had substantial staying power in the literature. In the present report, we examine whether a third dimension-reflecting the social properties of emotion-might arise if stimuli high in that dimension (i.e., "theoretically social emotions") were included in the task and, or, if social information was primed. We used a similarity-rating task to evaluate whether a dimension representing the "socialness" of emotion-the extent to which emotions are associated with social contexts-might arise as the result of inclusion of emotion words that are theorized to represent "social emotions." In Study 1, we assessed the dimensional structure of 41 different emotion terms (of which 41% were "social emotions") based on pairwise similarity ratings of a subset of the emotion terms. In Study 2, we tested whether priming social information before and during the similarity rating task would shift the emergent dimensional structure of emotion words. Results of multidimensional scaling across both studies indicated that the structure of emotion is best described by 2 dimensions-valence and arousal-and was not influenced by the priming of social information. Contrary to predictions, evidence did not emerge for a third dimension corresponding to socialness, nor any other property. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Collapse
|
9
|
Baxter MG, Santistevan AC, Bliss-Moreau E, Morrison JH. Timing of cyclic estradiol treatment differentially affects cognition in aged female rhesus monkeys. Behav Neurosci 2018; 132:213-223. [PMID: 29952604 PMCID: PMC6062474 DOI: 10.1037/bne0000259] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Some evidence suggests that there may be a limited "window of opportunity" for beneficial effects of hormone therapy after menopause in women. We tested whether the timing of cyclic estradiol (E2) treatment impacted its effect on cognitive function in aged, surgically menopausal (ovariectomized) rhesus monkeys. Monkeys were assigned to one of four treatment conditions after ovariectomy: either vehicle or E2 treatment for the duration of the protocol, vehicle for the first 2 years of the protocol followed by E2 for the remainder (delayed treatment), or E2 for the first 11 months of the protocol followed by vehicle for the remainder (withdrawn treatment). Delayed treatment addressed the hypothesis that E2 treatment initiated more than 2 years postovariectomy would have a reduced effect on cognitive function. Withdrawn treatment mirrored current clinical advice to women to use hormone therapy in the initial postmenopausal period then discontinue it. Two periods of cognitive testing assessed treatment effects on cognition over time. E2 treatment predominantly affected a prefrontal cortex-dependent test of spatiotemporal working memory (delayed response). Monkeys with delayed E2 treatment modestly improved in delayed response performance over time, whereas vehicle-treated monkeys declined. Monkeys with withdrawn E2 treatment maintained their performance across assessments, as did monkeys treated with E2 across the entire protocol. These findings suggest that a "window of opportunity" for hormone treatment after cessation of ovarian function, if present in nonhuman primates, lasts longer than 2 years. They also support the notion that beneficial effects of hormone therapy may persist after discontinuation of treatment. (PsycINFO Database Record
Collapse
Affiliation(s)
- Mark G Baxter
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai
| | - Anthony C Santistevan
- Department of Psychology, University of California, Davis, and California National Primate Research Center, Davis
| | - Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis, and California National Primate Research Center, Davis
| | - John H Morrison
- Department of Psychology, University of California, Davis, and California National Primate Research Center, Davis
| |
Collapse
|