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Drzewiecki CM, Fox AS. Understanding the heterogeneity of anxiety using a translational neuroscience approach. Cogn Affect Behav Neurosci 2024; 24:228-245. [PMID: 38356013 DOI: 10.3758/s13415-024-01162-3] [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] [Subscribe] [Scholar Register] [Accepted: 01/14/2024] [Indexed: 02/16/2024]
Abstract
Anxiety disorders affect millions of people worldwide and present a challenge in neuroscience research because of their substantial heterogeneity in clinical presentation. While a great deal of progress has been made in understanding the neurobiology of fear and anxiety, these insights have not led to effective treatments. Understanding the relationship between phenotypic heterogeneity and the underlying biology is a critical first step in solving this problem. We show translation, reverse translation, and computational modeling can contribute to a refined, cross-species understanding of fear and anxiety as well as anxiety disorders. More specifically, we outline how animal models can be leveraged to develop testable hypotheses in humans by using targeted, cross-species approaches and ethologically informed behavioral paradigms. We discuss reverse translational approaches that can guide and prioritize animal research in nontraditional research species. Finally, we advocate for the use of computational models to harmonize cross-species and cross-methodology research into anxiety. Together, this translational neuroscience approach will help to bridge the widening gap between how we currently conceptualize and diagnose anxiety disorders, as well as aid in the discovery of better treatments for these conditions.
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Affiliation(s)
- Carly M Drzewiecki
- California National Primate Research Center, University of California, Davis, CA, USA.
| | - Andrew S Fox
- California National Primate Research Center, University of California, Davis, CA, USA.
- Department of Psychology, University of California, Davis, CA, USA.
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2
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Holley D, Campos LJ, Drzewiecki CM, Zhang Y, Capitanio JP, Fox AS. Rhesus infant nervous temperament predicts peri-adolescent central amygdala metabolism & behavioral inhibition measured by a machine-learning approach. Transl Psychiatry 2024; 14:148. [PMID: 38490997 PMCID: PMC10943234 DOI: 10.1038/s41398-024-02858-3] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/18/2024] Open
Abstract
Anxiety disorders affect millions of people worldwide and impair health, happiness, and productivity on a massive scale. Developmental research points to a connection between early-life behavioral inhibition and the eventual development of these disorders. Our group has previously shown that measures of behavioral inhibition in young rhesus monkeys (Macaca mulatta) predict anxiety-like behavior later in life. In recent years, clinical and basic researchers have implicated the central extended amygdala (EAc)-a neuroanatomical concept that includes the central nucleus of the amygdala (Ce) and the bed nucleus of the stria terminalis (BST)-as a key neural substrate for the expression of anxious and inhibited behavior. An improved understanding of how early-life behavioral inhibition relates to an increased lifetime risk of anxiety disorders-and how this relationship is mediated by alterations in the EAc-could lead to improved treatments and preventive strategies. In this study, we explored the relationships between infant behavioral inhibition and peri-adolescent defensive behavior and brain metabolism in 18 female rhesus monkeys. We coupled a mildly threatening behavioral assay with concurrent multimodal neuroimaging, and related those findings to various measures of infant temperament. To score the behavioral assay, we developed and validated UC-Freeze, a semi-automated machine-learning (ML) tool that uses unsupervised clustering to quantify freezing. Consistent with previous work, we found that heightened Ce metabolism predicted elevated defensive behavior (i.e., more freezing) in the presence of an unfamiliar human intruder. Although we found no link between infant-inhibited temperament and peri-adolescent EAc metabolism or defensive behavior, we did identify infant nervous temperament as a significant predictor of peri-adolescent defensive behavior. Our findings suggest a connection between infant nervous temperament and the eventual development of anxiety and depressive disorders. Moreover, our approach highlights the potential for ML tools to augment existing behavioral neuroscience methods.
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Affiliation(s)
- D Holley
- University of California, Department of Psychology, Davis, CA, USA
- California National Primate Research Center, Davis, CA, USA
| | - L J Campos
- University of California, Department of Psychology, Davis, CA, USA
- California National Primate Research Center, Davis, CA, USA
| | - C M Drzewiecki
- California National Primate Research Center, Davis, CA, USA
| | - Y Zhang
- Columbia University, Department of Statistics, New York, NY, USA
| | - J P Capitanio
- University of California, Department of Psychology, Davis, CA, USA
- California National Primate Research Center, Davis, CA, USA
| | - A S Fox
- University of California, Department of Psychology, Davis, CA, USA.
- California National Primate Research Center, Davis, CA, USA.
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Drzewiecki CM, Brinks AS, Sellinger EP, Doshi AD, Koh JY, Juraska JM. Brief postnatal exposure to bisphenol A affects apoptosis and gene expression in the medial prefrontal cortex and social behavior in rats with sex specificity. Neurotoxicology 2023; 94:126-134. [PMID: 36442689 PMCID: PMC9839503 DOI: 10.1016/j.neuro.2022.11.011] [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: 07/21/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
Bisphenol A (BPA) is an endocrine disruptor found in polycarbonate plastics and exposure in humans is nearly ubiquitous and it has widespread effects on cognitive, emotional, and reproductive behaviors in both humans and animal models. In our laboratory we previously found that perinatal BPA exposure results in a higher number of neurons in the adult male rat prefrontal cortex (PFC) and less play in adolescents of both sexes. Here we examine changes in the rate of postnatal apoptosis in the rat prefrontal cortex and its timing with brief BPA exposure. Because an increased number of neurons in the PFC is a characteristic of a subtype of autism spectrum disorder, we tested social preference following brief BPA exposure and also expression of a small group of genes. Males and females were exposed to BPA from postnatal days (P) 6 through 8 or from P10 through 12. Both exposures significantly decreased indicators of cell death in the developing medial prefrontal cortex in male subjects only. Additionally, males exposed to BPA from P6 - 8 showed decreased social preference and decreased cortical expression of Shank3 and Homer1, two synaptic scaffolding genes that have been implicated in social deficits. There were no significant effects of BPA in the female subjects. These results draw attention to the negative consequences following brief exposure to BPA during early development.
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Affiliation(s)
- Carly M Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA; Currently at California National Primate Research Center, University of California-Davis, Davis, CA, 95616, USA
| | - Amara S Brinks
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
| | - Elli P Sellinger
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
| | - Aditi D Doshi
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL, 61820, USA; Currently at Department of Psychology, University of Illinois at Chicago, 1007W Harrison St, Chicago, IL 60607, USA
| | - Jessie Y Koh
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL, 61820, USA
| | - Janice M Juraska
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA; Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL, 61820, USA.
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Milham M, Petkov C, Belin P, Ben Hamed S, Evrard H, Fair D, Fox A, Froudist-Walsh S, Hayashi T, Kastner S, Klink C, Majka P, Mars R, Messinger A, Poirier C, Schroeder C, Shmuel A, Silva AC, Vanduffel W, Van Essen DC, Wang Z, Roe AW, Wilke M, Xu T, Aarabi MH, Adolphs R, Ahuja A, Alvand A, Amiez C, Autio J, Azadi R, Baeg E, Bai R, Bao P, Basso M, Behel AK, Bennett Y, Bernhardt B, Biswal B, Boopathy S, Boretius S, Borra E, Boshra R, Buffalo E, Cao L, Cavanaugh J, Celine A, Chavez G, Chen LM, Chen X, Cheng L, Chouinard-Decorte F, Clavagnier S, Cléry J, Colcombe SJ, Conway B, Cordeau M, Coulon O, Cui Y, Dadarwal R, Dahnke R, Desrochers T, Deying L, Dougherty K, Doyle H, Drzewiecki CM, Duyck M, Arachchi WE, Elorette C, Essamlali A, Evans A, Fajardo A, Figueroa H, Franco A, Freches G, Frey S, Friedrich P, Fujimoto A, Fukunaga M, Gacoin M, Gallardo G, Gao L, Gao Y, Garside D, Garza-Villarreal EA, Gaudet-Trafit M, Gerbella M, Giavasis S, Glen D, Ribeiro Gomes AR, Torrecilla SG, Gozzi A, Gulli R, Haber S, Hadj-Bouziane F, Fujimoto SH, Hawrylycz M, He Q, He Y, Heuer K, Hiba B, Hoffstaedter F, Hong SJ, Hori Y, Hou Y, Howard A, de la Iglesia-Vaya M, Ikeda T, Jankovic-Rapan L, Jaramillo J, Jedema HP, Jin H, Jiang M, Jung B, Kagan I, Kahn I, Kiar G, Kikuchi Y, Kilavik B, Kimura N, Klatzmann U, Kwok SC, Lai HY, Lamberton F, Lehman J, Li P, Li X, Li X, Liang Z, Liston C, Little R, Liu C, Liu N, Liu X, Liu X, Lu H, Loh KK, Madan C, Magrou L, Margulies D, Mathilda F, Mejia S, Meng Y, Menon R, Meunier D, Mitchell A, Mitchell A, Murphy A, Mvula T, Ortiz-Rios M, Ortuzar Martinez DE, Pagani M, Palomero-Gallagher N, Pareek V, Perkins P, Ponce F, Postans M, Pouget P, Qian M, Ramirez J“B, Raven E, Restrepo I, Rima S, Rockland K, Rodriguez NY, Roger E, Hortelano ER, Rosa M, Rossi A, Rudebeck P, Russ B, Sakai T, Saleem KS, Sallet J, Sawiak S, Schaeffer D, Schwiedrzik CM, Seidlitz J, Sein J, Sharma J, Shen K, Sheng WA, Shi NS, Shim WM, Simone L, Sirmpilatze N, Sivan V, Song X, Tanenbaum A, Tasserie J, Taylor P, Tian X, Toro R, Trambaiolli L, Upright N, Vezoli J, Vickery S, Villalon J, Wang X, Wang Y, Weiss AR, Wilson C, Wong TY, Woo CW, Wu B, Xiao D, Xu AG, Xu D, Xufeng Z, Yacoub E, Ye N, Ying Z, Yokoyama C, Yu X, Yue S, Yuheng L, Yumeng X, Zaldivar D, Zhang S, Zhao Y, Zuo Z. Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging. Neuron 2022; 110:16-20. [PMID: 34731649 DOI: 10.1016/j.neuron.2021.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/30/2021] [Accepted: 10/11/2021] [Indexed: 12/22/2022]
Abstract
Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently developed a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience.
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Drzewiecki CM, Sellinger EP, Juraska JM. Impact of pubertal onset on region-specific Esr2 expression. J Neuroendocrinol 2021; 33:e13029. [PMID: 34463394 PMCID: PMC8448167 DOI: 10.1111/jne.13029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/12/2021] [Accepted: 08/08/2021] [Indexed: 11/28/2022]
Abstract
In female rats, pubertal onset is associated with maturation of the medial prefrontal cortex (mPFC) and mPFC-mediated behaviours. These behavioural and anatomical changes are likely a result of the effects of oestrogens at the nuclear oestrogen receptor (ER)β, which is expressed at higher levels than the ERα isoform in the adult mPFC. Researchers have previously quantified ERβ protein and Esr2 RNA in rodents during early postnatal development and adulthood, although an adolescent-specific trajectory of this receptor in the mPFC has not been documented. Given that Esr2 expression can fluctuate in the presence or absence of oestrogens, puberty and the subsequent rise in gonadal hormones could influence levels of ERβ in the adolescent brain. To further explore this, we used RNAscope® technology to quantify the amount of Esr2 mRNA in pre-pubertal adolescent, recently post-pubertal adolescent and adult female rats. We show that Esr2 expression decreases significantly in the mPFC, striatum and motor cortex between pre-pubertal adolescence and adulthood. In the mPFC, this decrease occurs rapidly at pubertal onset, with no significant decrease in Esr2 levels between the recently post-pubertal and adult cohort. By contrast, the striatum and motor cortex had no significant differences in the amount of Esr2 mRNA between pre- and post-pubertal females. Insofar as the amount of Esr2 expression is proportional to functional ERβ, these results suggest ERβ decreases in a region-specific pattern in response to pubertal onset and highlight a role for this receptor in the maturational events that occur in the female rat mPFC at puberty.
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Affiliation(s)
- Carly M. Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820
- Currently at California National Primate Research Center, University of California-Davis, Davis, CA, 95616
| | - Elli P. Sellinger
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820
| | - Janice M. Juraska
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61820
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, 61820
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Sellinger EP, Drzewiecki CM, Willing J, Juraska JM. Cell death in the male and female rat medial prefrontal cortex during early postnatal development. IBRO Neurosci Rep 2021; 10:186-190. [PMID: 33870262 PMCID: PMC8044638 DOI: 10.1016/j.ibneur.2021.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
Apoptosis, programmed cell death, is a critical component of neurodevelopment occurring in temporal, spatial, and at times, sex-specific, patterns across the cortex during the early postnatal period. During this time, the brain is particularly susceptible to environmental influences that are often used in animal models of neurodevelopmental disorders. In the present study, the timing of peak cell death was assessed by the presence of pyknotic cells in the male and female rat medial prefrontal cortex (mPFC), a cortical region that in humans, is often involved in developmental disorders. One male and one female rat per litter were sacrificed at the following ages: postnatal day (P)2, 4, 6, 8, 10, 12, 14, 16, 18, and 25. The mPFC was Nissl-stained, the densities of pyknotic cells and live neurons were stereologically collected, and the number of pyknotic cells per 100 live neurons, pyknotic cell density, and neuron density were analyzed. Males and females showed a significant peak in the ratio of pyknotic to live neurons on P8, and in females, this elevation persisted through P12. Likewise, the density of pyknotic cells peaked on P8 in both sexes and persisted through P12 in females. The timing of cell death within the rat mPFC will inform study design in experiments that employ early environmental manipulations that might disrupt this process. The number of pyknotic cells per live neuron was quantified. Postnatal cell death peaked on P8 in the male rat medial prefrontal cortex. In females, postnatal cell death peaked from P8 to P12.
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Affiliation(s)
- Elli P Sellinger
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States
| | - Carly M Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States
| | - Jari Willing
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL 61820, United States
| | - Janice M Juraska
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL 61820, United States
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Drzewiecki CM, Willing J, Cortes LR, Juraska JM. Adolescent stress during, but not after, pubertal onset impairs indices of prepulse inhibition in adult rats. Dev Psychobiol 2021; 63:837-850. [PMID: 33629385 DOI: 10.1002/dev.22111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 10/03/2020] [Revised: 01/12/2021] [Accepted: 02/01/2021] [Indexed: 02/01/2023]
Abstract
Exposure to stress during adolescence is a risk factor for developing several psychiatric disorders, many of which involve prefrontal cortex (PFC) dysfunction. The human PFC and analogous rodent medial prefrontal cortex (mPFC) continue to mature functionally and anatomically during adolescence, and some of these maturational events coincide with pubertal onset. As developing brain regions are more susceptible to the negative effects of stress, this may make puberty especially vulnerable. To test this, we exposed male and female rats to isolation and restraint stress during the onset of puberty or during the post-pubertal period of adolescence. In young adulthood, both stressed groups and an unstressed control group underwent testing on a battery of tasks to assess emotional and cognitive behaviors, and the volume of the mPFC was quantified postmortem. Factor analysis revealed only subjects stressed peri-pubertally showed a long-term deficiency compared to controls in prepulse inhibition. Additionally, both sexes showed volumetric mPFC decreases following adolescent stress, and these losses were most pronounced in females. Our findings suggest that pubertal onset may be a vulnerable window wherein adolescents are most susceptible to the negative consequences of stress exposure. Furthermore, it highlights the importance of accounting for pubertal status when studying adolescents.
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Affiliation(s)
- Carly M Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Jari Willing
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA.,Department of Psychology, Bowling Green State University, 822 E Merry Ave, Bowling Green, OH, 43403, USA
| | - Laura R Cortes
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA.,Neuroscience Institute, Georgia State University, 100 Piedmont Ave SE, Atlanta, GA, 30303, USA
| | - Janice M Juraska
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL, USA.,Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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Drzewiecki CM, Juraska JM. The structural reorganization of the prefrontal cortex during adolescence as a framework for vulnerability to the environment. Pharmacol Biochem Behav 2020; 199:173044. [DOI: 10.1016/j.pbb.2020.173044] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/04/2020] [Accepted: 09/30/2020] [Indexed: 11/26/2022]
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Drzewiecki CM, Willing J, Juraska JM. Influences of age and pubertal status on number and intensity of perineuronal nets in the rat medial prefrontal cortex. Brain Struct Funct 2020; 225:2495-2507. [PMID: 32914251 DOI: 10.1007/s00429-020-02137-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [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: 12/09/2019] [Accepted: 08/29/2020] [Indexed: 12/20/2022]
Abstract
The prefrontal cortex (PFC) is a late developing region of the cortex, and its protracted maturation during adolescence may confer a period of plasticity. Closure of critical, or sensitive, periods in sensory cortices coincides with perineuronal net (PNN) expression, leading to enhanced inhibitory function and synaptic stabilization. PNN density has been found to increase across adolescence in the male rat medial PFC (mPFC). Here, we examined both male and female rats at four time points spanning adolescent development to stereologically quantify the number and intensity of PNNs in the mPFC. Additionally, because puberty coincides with broad behavioral and neuroanatomical changes, we collected tissue from age-matched pre- and post-pubertal siblings within a litter. Results indicate that both males and females show an increase in the total number and intensity of mPFC PNNs between postnatal day (P) 30 and P60. As we have previously found, white matter under the mPFC also increased at the same time. Male puberty did not affect PNNs, while female pubertal onset led to an abrupt decrease in the total number of PNNs that persisted through mid-adolescence before increasing at P60. Despite the change in PNN number, the intensity of female PNNs was not affected by puberty. Thus, though males and females show increases in mPFC PNNs during adolescence, the pubertal decrease in the number of PNNs in female rats may indicate a difference in the pattern of maximal plasticity between the sexes during adolescence.
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Affiliation(s)
- Carly M Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA
| | - Jari Willing
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL, 61820, USA.,Department of Psychology, Bowling Green State University, 822 E Merry Ave, Bowling Green, OH, 43403, USA
| | - Janice M Juraska
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA. .,Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, IL, 61820, USA.
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Sellinger EP, Kougias DG, Drzewiecki CM, Juraska JM. Behavioral effects in adult rats exposed to low doses of a phthalate mixture during the perinatal or adolescent period. Neurotoxicol Teratol 2020; 79:106886. [PMID: 32315766 DOI: 10.1016/j.ntt.2020.106886] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 12/19/2019] [Revised: 03/13/2020] [Accepted: 04/13/2020] [Indexed: 11/30/2022]
Abstract
Hormones influence neurodevelopment which can result in vulnerability to endocrine disruptors such as phthalates during both the perinatal period and adolescence. Using a rat model, we have previously shown that perinatal exposure to an environmentally relevant phthalate mixture at low doses results in cognitive flexibility deficits in adults and a reduction in neuron and synapse number within the medial prefrontal cortex. Here, we further examined the behavioral effects of exposure to an environmentally relevant mixture of phthalates at low doses during either perinatal development or adolescence. Using the elevated plus maze, adult females, not males, exposed to phthalates during adolescence showed indications of reduced anxiety-like behavior while perinatal exposed animals were unaffected. There was no effect of adolescent phthalate exposure on cognitive flexibility using the attentional set shift paradigm in either sex, unlike the impairments we have previously reported following perinatal exposure (Kougias et al., 2018b). Finally, there was no effect of phthalate exposure during either time frame on sensorimotor gating measured using prepulse inhibition. Environmentally relevant phthalate exposure during the perinatal period or during adolescence did not induce widespread changes in the adult behaviors measured here.
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Affiliation(s)
- Elli P Sellinger
- Neuroscience Program, University of Illinois, 603 E. Daniel St., Champaign, IL 61820, United States of America
| | - Daniel G Kougias
- Neuroscience Program, University of Illinois, 603 E. Daniel St., Champaign, IL 61820, United States of America
| | - Carly M Drzewiecki
- Neuroscience Program, University of Illinois, 603 E. Daniel St., Champaign, IL 61820, United States of America
| | - Janice M Juraska
- Department of Psychology, University of Illinois, 603 E. Daniel St., Champaign, IL 61820, United States of America; Neuroscience Program, University of Illinois, 603 E. Daniel St., Champaign, IL 61820, United States of America.
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Drzewiecki CM, Willing J, Juraska JM. Synaptic number changes in the medial prefrontal cortex across adolescence in male and female rats: A role for pubertal onset. Synapse 2016; 70:361-8. [PMID: 27103097 DOI: 10.1002/syn.21909] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [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: 12/16/2015] [Revised: 03/30/2016] [Accepted: 04/19/2016] [Indexed: 12/24/2022]
Abstract
Adolescence is a unique period of development, marked by maturation of the prefrontal cortex (PFC), a region important for executive functioning. During this time, the human PFC decreases in overall volume and thickness. Likewise in adolescent rodents, losses of neurons, dendrites, dendritic spines and neurotransmitter receptors have been documented within the medial prefrontal cortex (mPFC), sometimes with sex and layer specificity. However, changes in the number of synapses during this time have not been examined. In the present study, we stereologically quantified the number of synaptophysin-immunoreactive boutons in the male and female rat mPFC across multiple time points from the juvenile period through adulthood (postnatal days (P) 25, 35, 45, 60 and 90). In females, there was a significant decrease in synaptophysin boutons between P35 and P45, coinciding with the onset of puberty. In males, there was no significant main effect of age on synaptophysin boutons; however, in both males and females, pubertal onset was associated with significant synaptic losses. These results suggest that puberty is a critical period for synaptic pruning within the rat mPFC, potentially contributing to maturation of adolescent executive function. Synapse 70:361-368, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Carly M Drzewiecki
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, Illinois, 61820
| | - Jari Willing
- Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, Illinois, 61820
| | - Janice M Juraska
- Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, Illinois, 61820.,Department of Psychology, University of Illinois at Urbana-Champaign, 603 E Daniel St, Champaign, Illinois, 61820
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12
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Abstract
Adolescence is characterized by neuroanatomical changes that coincide with increased cognitive performance. This developmental period is particularly important for the medial prefrontal cortex (mPFC), which mediates higher-order cognitive functioning. The authors' laboratory has shown that puberty is associated with sex-specific changes in neuron number and the dendritic tree in the rat mPFC, but the effects of pubertal onset on cognitive performance remain relatively unexplored. Here, we use a water maze task to assess spatial memory for the location of an escape platform, followed by a test of reversal learning, when the platform is moved to an alternate quadrant in the maze. For both males and females, 2 groups of prepubertal animals were tested (postnatal day [P]30 and P33 for females, P40 and P43 for males), along with 1 group of newly (2 days) postpubertal animals and 1 group of young adults (P60). There were no group differences in learning the initial location of the platform or when the platform location changed, although grouping pre- and postpubertal ages did result in significantly better performance in postpubertal animals. In addition after the platform location changed, individual prepubertal males and females spent a significantly greater percentage of time in the quadrant of the maze where the platform was formerly located than the postpubertal animals. This collectively implies that pubertal onset in both males and females coincides with improved performance on a reversal task, which may be linked with the neuroanatomical changes occurring in the mPFC during this time. (PsycINFO Database Record
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Affiliation(s)
- Jari Willing
- Department of Psychology, Behavioral Neuroscience Division
| | | | | | - Laura R Cortes
- Department of Psychology, Behavioral Neuroscience Division
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