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Acosta MC, Hussein M, Saltzman W. Effects of acute inhibition of dopamine β-hydroxylase on neural responses to pups in adult virgin male California mice (Peromyscus californicus). Behav Brain Res 2024; 471:115116. [PMID: 38897419 DOI: 10.1016/j.bbr.2024.115116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/09/2024] [Accepted: 06/15/2024] [Indexed: 06/21/2024]
Abstract
The neural mechanisms underlying paternal care in biparental mammals are not well understood. The California mouse (Peromyscus californicus) is a biparental rodent in which virtually all fathers are attracted to pups, while virgin males vary widely in their behavior toward unrelated infants, ranging from attacking to avoiding to huddling and grooming pups. We previously showed that pharmacologically inhibiting the synthesis of the neurotransmitter norepinephrine (NE) with the dopamine β-hydroxylase inhibitor nepicastat reduced the propensity of virgin male and female California mice to interact with pups. The current study tested the hypothesis that nepicastat would reduce pup-induced c-Fos immunoreactivity, a cellular marker of neural activity, in the medial preoptic area (MPOA), medial amygdala (MeA), basolateral amygdala (BLA), and bed nucleus of the stria terminalis (BNST), brain regions implicated in the control of parental behavior and/or anxiety. Virgin males were injected with nepicastat (75 mg/kg, i.p.) or vehicle 2 hours prior to exposure to either an unrelated pup or novel object for 60 minutes (n = 4-6 mice per group). Immediately following the 60-minute stimulus exposure, mice were euthanized and their brains were collected for c-Fos immunohistochemistry. Nepicastat reduced c-Fos expression in the MeA and MPOA of pup-exposed virgin males compared to vehicle-injected controls. In contrast, nepicastat did not alter c-Fos expression in any of the above brain regions following exposure to a novel object. Overall, these results suggest that the noradrenergic system might influence MeA and MPOA function to promote behavioral interactions with pups in virgin males.
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Affiliation(s)
- Melina C Acosta
- Graduate Program in Neuroscience, University of California, Riverside, CA 92521, USA; Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - Manal Hussein
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - Wendy Saltzman
- Graduate Program in Neuroscience, University of California, Riverside, CA 92521, USA; Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA.
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Locus Coeruleus-Noradrenergic Neurons Regulate Stress Coping During Subchronic Exposure to Social Threats: A Characteristic Feature in Postpartum Female Mice. Cell Mol Neurobiol 2022:10.1007/s10571-022-01314-4. [PMID: 36577871 DOI: 10.1007/s10571-022-01314-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 12/17/2022] [Indexed: 12/29/2022]
Abstract
Stress-coping strategies have been implicated in depression. The control of stress coping may improve the symptom and higher prevalence of depression during the postpartum period in women. However, the neuronal mechanisms underlying stress coping remain to be fully elucidated in postpartum women. In this study, we examined how locus coeruleus-noradrenergic (LC-NA) neurons, which have been associated with both stress coping and depression, regulate changes in coping style induced by subchronic exposure to unfamiliar male mice as a social threat in postpartum female mice. In contrast to virgin females, dams exposed to unfamiliar males daily for four consecutive days showed reduced immobility duration in the forced swim test, indicating that exposure to unfamiliar males decreased passive stress coping in dams. Exposure to unfamiliar males also decreased sucrose palatability in the sucrose preference test and suppressed the crouching behavior in the maternal care test but did not affect anxiety-like behavior in the hole-board test in dams. In fiber photometry analyses, LC-NA neurons showed differential activity between dams and virgin females in response to unfamiliar males. Chemogenetic inhibition of LC-NA neurons during exposure to unfamiliar males prevented the social threat-induced decrease in immobility duration in the forced swim test in dams. Furthermore, inhibition or activation of LC-NA neurons exacerbated crouching behavior in dams. These results indicate that LC-NA neurons regulate the social threat-induced decrease in passive stress coping and relieve social threat-induced inhibition of maternal care in postpartum female mice.
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Fuentes I, Morishita Y, Gonzalez-Salinas S, Champagne FA, Uchida S, Shumyatsky GP. Experience-Regulated Neuronal Signaling in Maternal Behavior. Front Mol Neurosci 2022; 15:844295. [PMID: 35401110 PMCID: PMC8987921 DOI: 10.3389/fnmol.2022.844295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Maternal behavior is shaped and challenged by the changing developmental needs of offspring and a broad range of environmental factors, with evidence indicating that the maternal brain exhibits a high degree of plasticity. This plasticity is displayed within cellular and molecular systems, including both intra- and intercellular signaling processes as well as transcriptional profiles. This experience-associated plasticity may have significant overlap with the mechanisms controlling memory processes, in particular those that are activity-dependent. While a significant body of work has identified various molecules and intracellular processes regulating maternal care, the role of activity- and experience-dependent processes remains unclear. We discuss recent progress in studying activity-dependent changes occurring at the synapse, in the nucleus, and during the transport between these two structures in relation to maternal behavior. Several pre- and postsynaptic molecules as well as transcription factors have been found to be critical in these processes. This role reflects the principal importance of the molecular and cellular mechanisms of memory formation to maternal and other behavioral adaptations.
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Affiliation(s)
- Ileana Fuentes
- Department of Genetics, Rutgers University, Piscataway, NJ, United States
| | | | | | - Frances A. Champagne
- Department of Psychology, University of Texas at Austin, Austin, TX, United States
| | - Shusaku Uchida
- SK Project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Gleb P. Shumyatsky
- Department of Genetics, Rutgers University, Piscataway, NJ, United States
- *Correspondence: Gleb P. Shumyatsky
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Ragan CM, Ahmed EI, Vitale EM, Linning-Duffy K, Miller-Smith SM, Maguire J, Lonstein JS. Postpartum State, but Not Maternal Caregiving or Level of Anxiety, Increases Medial Prefrontal Cortex GAD65 and vGAT in Female Rats. Front Glob Womens Health 2022; 2:746518. [PMID: 35211693 PMCID: PMC8861351 DOI: 10.3389/fgwh.2021.746518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/27/2021] [Indexed: 11/13/2022] Open
Abstract
Upregulation of the inhibitory neurotransmitter, GABA, is involved in many of the behavioral differences between postpartum and nulliparous female rodents. This is evidenced by studies showing that pharmacological blockade of GABAergic activity impairs maternal caregiving and postpartum affective behaviors. However, the influence of motherhood on the capacity for GABA synthesis or release in the medial prefrontal cortex (mPFC; brain region involved in many social and affective behaviors) is not well-understood. Western blotting was used to compare postpartum and nulliparous rats in protein levels of the 65-kD isoform of glutamic acid decarboxylase (GAD65; synthesizes most GABA released from terminals) and vesicular GABA transporter (vGAT; accumulates GABA into synaptic vesicles for release) in the mPFC. We found that postpartum mothers had higher GAD65 and vGAT compared to virgins, but such differences were not found between maternally sensitized and non-sensitized virgins, indicating that reproduction rather than just the display of maternal caregiving is required. To test whether GAD65 and vGAT levels in the mPFC were more specifically related to anxiety-related behavior within postpartum mothers, we selected 8 low-anxiety and 8 high-anxiety dams based on their time spent in the open arms of an elevated plus maze on postpartum day 7. There were no significant differences between the anxiety groups in either GAD65 or vGAT levels. These data further indicate that frontal cortical GABA is affected by female reproduction and more likely contributes to differences in the display of socioemotional behaviors across, but not within, female reproductive state.
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Affiliation(s)
- Christina M. Ragan
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
- School of Biology and Undergraduate Neuroscience Program, Georgia Institute of Technology, Atlanta, GA, United States
| | - Eman I. Ahmed
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Erika M. Vitale
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
| | | | - Stephanie M. Miller-Smith
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Jamie Maguire
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Joseph S. Lonstein
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Joseph S. Lonstein
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5
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Acosta MC, Tillage RP, Weinshenker D, Saltzman W. Acute inhibition of dopamine β-hydroxylase attenuates behavioral responses to pups in adult virgin California mice (Peromyscus californicus). Horm Behav 2022; 137:105086. [PMID: 34808463 PMCID: PMC9250832 DOI: 10.1016/j.yhbeh.2021.105086] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/01/2021] [Accepted: 11/06/2021] [Indexed: 01/17/2023]
Abstract
In biparental species, in which both parents care for their offspring, the neural and endocrine mediators of paternal behavior appear to overlap substantially with those underlying maternal behavior. Little is known, however, about the roles of classical neurotransmitters, such as norepinephrine (NE), in paternal care and whether they resemble those in maternal care. We tested the hypothesis that NE facilitates the initiation of nurturant behavior toward pups in virgin male and female California mice (Peromyscus californicus), a biparental rodent. Virtually all parents in this species are attracted to familiar and unfamiliar pups, while virgins either attack, avoid, or nurture pups, suggesting that the neurochemical control of pup-related behavior changes as mice transition into parenthood. We injected virgin males and females with nepicastat, a selective dopamine β-hydroxylase inhibitor that blocks NE synthesis (75 mg/kg, i.p.), or vehicle 2 h before exposing them to a novel pup, estrous female (males only), or pup-sized novel object for 60 min. Nepicastat significantly reduced the number of males and females that approached the pup and that displayed parental behavior. In contrast, nepicastat did not alter virgins' interactions with an estrous female or a novel object, suggesting that nepicastat-induced inhibition of interactions with pups was not mediated by changes in generalized neophobia, arousal, or activity. Nepicastat also significantly reduced NE levels in the amygdala and prefrontal cortex and increased the ratio of dopamine to NE in the hypothalamus. Our results suggest that NE may facilitate the initiation of parental behavior in male and female California mice.
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Affiliation(s)
- Melina C Acosta
- Graduate Program in Neuroscience, University of California, Riverside, CA 92521, USA; Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - Rachel P Tillage
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA 30322, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA 30322, USA
| | - Wendy Saltzman
- Graduate Program in Neuroscience, University of California, Riverside, CA 92521, USA; Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA.
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6
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Winokur SB, Lopes KL, Moparthi Y, Pereira M. Depression-related disturbances in rat maternal behaviour are associated with altered monoamine levels within mesocorticolimbic structures. J Neuroendocrinol 2019; 31:e12766. [PMID: 31265182 DOI: 10.1111/jne.12766] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 12/25/2022]
Abstract
The ability of mothers to sensitively attune their maternal responses to the needs of their developing young is fundamental to a healthy mother-young relationship. The biological mechanisms that govern how mothers adjust caregiving to the dynamic changes in the demands of the young remain an open question. In the present study, we examined whether changes in monoamine levels, within discrete mesocorticolimbic structures involved in cognitive and motivational processes key to parenting, modulate this flexibility in caregiving across the postpartum period. The present study used a Wistar-Kyoto (WKY) animal model of depression and control Sprague-Dawley (SD) rats, which differ dramatically in their cognitive, motivational, and parenting performance. Levels of the monoamine neurotransmitters, dopamine, noradrenaline and serotonin, as well as their major metabolites, were measured within the medial prefrontal cortex, striatum, nucleus accumbens and medial preoptic area of SD and WKY mothers at early (postpartum day [PPD]7-8), late (PPD15-16) and weaning (PPD25) postpartum stages using high-performance liquid chromatography with electrochemical detection. Consistent with our prior work, we find that caregiving of SD mothers declined as the postpartum period progressed. Relative to nulliparous females, early postpartum mothers had lower intracellular concentrations of monoamines, as well as lower noradrenaline turnover, and an elevated serotonin turnover within most structures. Postpartum behavioural trajectories subsequently corresponded to a progressive increase in all three monoamine levels within multiple structures. Compared to SD mothers, WKY mothers were inconsistent and disorganised in caring for their offspring and exhibit profound deficits in maternal behaviour. Additionally, WKY mothers had generally lower levels of all three monoamines, as well as different patterns of change across the postpartum period, compared to SD mothers, suggesting dysfunctional central monoamine pathways in WKY mothers as they transition and experience motherhood. Taken together, the results of the present study suggest a role for monoamines at multiple mesocorticolimbic structures with repect to modulating caregiving behaviours attuned to the changing needs of the young.
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Affiliation(s)
- Sarah B Winokur
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Keianna L Lopes
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Yashaswani Moparthi
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Mariana Pereira
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
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Fang YY, Yamaguchi T, Song SC, Tritsch NX, Lin D. A Hypothalamic Midbrain Pathway Essential for Driving Maternal Behaviors. Neuron 2019; 98:192-207.e10. [PMID: 29621487 DOI: 10.1016/j.neuron.2018.02.019] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/11/2018] [Accepted: 02/21/2018] [Indexed: 01/03/2023]
Abstract
Maternal behaviors are essential for the survival of the young. Previous studies implicated the medial preoptic area (MPOA) as an important region for maternal behaviors, but details of the maternal circuit remain incompletely understood. Here we identify estrogen receptor alpha (Esr1)-expressing cells in the MPOA as key mediators of pup approach and retrieval. Reversible inactivation of MPOAEsr1+ cells impairs those behaviors, whereas optogenetic activation induces immediate pup retrieval. In vivo recordings demonstrate preferential activation of MPOAEsr1+ cells during maternal behaviors and changes in MPOA cell responses across reproductive states. Furthermore, channelrhodopsin-assisted circuit mapping reveals a strong inhibitory projection from MPOAEsr1+ cells to ventral tegmental area (VTA) non-dopaminergic cells. Pathway-specific manipulations reveal that this projection is essential for driving pup approach and retrieval and that VTA dopaminergic cells are reliably activated during those behaviors. Altogether, this study provides new insight into the neural circuit that generates maternal behaviors.
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Affiliation(s)
- Yi-Ya Fang
- Neuroscience Institute, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA
| | - Takashi Yamaguchi
- Neuroscience Institute, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA
| | - Soomin C Song
- Neuroscience Institute, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA
| | - Nicolas X Tritsch
- Neuroscience Institute, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA
| | - Dayu Lin
- Neuroscience Institute, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA; Department of Psychiatry, New York University School of Medicine, 1 Park Avenue, New York, NY 10016, USA; Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
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Klampfl SM, Bosch OJ. Mom doesn't care: When increased brain CRF system activity leads to maternal neglect in rodents. Front Neuroendocrinol 2019; 53:100735. [PMID: 30684507 DOI: 10.1016/j.yfrne.2019.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/22/2018] [Accepted: 01/18/2019] [Indexed: 12/18/2022]
Abstract
Mothers are the primary caregivers in mammals, ensuring their offspring's survival. This strongly depends on the adequate expression of maternal behavior, which is the result of a concerted action of "pro-maternal" versus "anti-maternal" neuromodulators such as the oxytocin and corticotropin-releasing factor (CRF) systems, respectively. When essential peripartum adaptations fail, the CRF system has negative physiological, emotional and behavioral consequences for both mother and offspring often resulting in maternal neglect. Here, we provide an elaborate and unprecedented review on the implications of the CRF system in the maternal brain. Studies in rodents have advanced our understanding of the specific roles of brain regions such as the limbic bed nucleus of the stria terminalis, medial preoptic area and lateral septum even in a CRF receptor subtype-specific manner. Furthermore, we discuss potential interactions of the CRF system with other neurotransmitters like oxytocin and noradrenaline, and present valuable translational aspects of the recent research.
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Affiliation(s)
- Stefanie M Klampfl
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Oliver J Bosch
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany.
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9
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Pawluski JL, Li M, Lonstein JS. Serotonin and motherhood: From molecules to mood. Front Neuroendocrinol 2019; 53:100742. [PMID: 30878665 PMCID: PMC6541513 DOI: 10.1016/j.yfrne.2019.03.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/27/2019] [Accepted: 03/12/2019] [Indexed: 12/20/2022]
Abstract
Emerging research points to a valuable role of the monoamine neurotransmitter, serotonin, in the display of maternal behaviors and reproduction-associated plasticity in the maternal brain. Serotonin is also implicated in the pathophysiology of numerous affective disorders and likely plays an important role in the pathophysiology of maternal mental illness. Therefore, the main goals of this review are to detail: (1) how the serotonin system of the female brain changes across pregnancy and postpartum; (2) the role of the central serotonergic system in maternal caregiving and maternal aggression; and (3) how the serotonin system and selective serotonin reuptake inhibitor medications (SSRIs) are involved in the treatment of maternal mental illness. Although there is much work to be done, studying the central serotonin system's multifaceted role in the maternal brain is vital to our understanding of the processes governing matrescence and the maintenance of motherhood.
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Affiliation(s)
- Jodi L Pawluski
- Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail), UMR_S 1085, F-35000 Rennes, France.
| | - Ming Li
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE 68588-0308, USA.
| | - Joseph S Lonstein
- Neuroscience Program & Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
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Holschbach MA, Vitale EM, Lonstein JS. Serotonin-specific lesions of the dorsal raphe disrupt maternal aggression and caregiving in postpartum rats. Behav Brain Res 2018; 348:53-64. [PMID: 29653128 DOI: 10.1016/j.bbr.2018.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/28/2018] [Accepted: 04/06/2018] [Indexed: 11/29/2022]
Abstract
The behavioral modifications associated with early motherhood, which include high aggression, caring for the young, and low anxiety, are all affected by acute pharmacological manipulation of serotonin signaling. However, the effects on all these behaviors of permanently disrupting serotonin signaling from one of its primary sources, the dorsal raphe nucleus (DR), have not been examined in detail. To address this, serotonin-specific lesions centered on the dorsomedial DR (DRdm; DR subregion strongly implicated in emotional behaviors) were induced at mid-pregnancy (day 15) or early postpartum (day 2) in rats using a saporin-conjugated neurotoxin targeting the serotonin transporter (Anti-SERT-SAP). Prepartum or postpartum Anti-SERT-SAP reduced DRdm serotonin immunoreactivity by ∼40-65%, and postpartum Anti-SERT-SAP also reduced it in the ventromedial and lateral wings of the DR, as well as in the median raphe. Serotonin-immunoreactive fibers were significantly reduced in the anterior hypothalamus, but not medial preoptic area, of lesioned dams. Pre- or postpartum lesions both greatly reduced maternal aggression, but while prepartum lesions did not affect later undisturbed maternal caregiving, the larger postpartum lesions prevented the postpartum decline in kyphotic nursing and reduced pup licking. Serotonin lesions did not affect pup retrieval, but the prepartum lesions temporarily increased maternal hovering over and licking the pups observed immediately after the disruptive retrieval tests. Dams' anxiety-like behaviors and litter weight gains were unaffected by the lesions. These findings suggest that DRdm serotonin projecting to the AH is particularly critical for maternal aggression, but that more widespread disruption of midbrain raphe serotonin is necessary to greatly impair maternal caregiving. Postpartum anxiety may rely more on other neurochemical systems or different midbrain serotonergic cell populations.
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Affiliation(s)
- M Allie Holschbach
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA
| | - Erika M Vitale
- Department of Psychology, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA
| | - Joseph S Lonstein
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA; Department of Psychology, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA.
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11
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Blockade of α2-adrenergic receptors in prelimbic cortex: impact on cocaine self-administration in adult spontaneously hypertensive rats following adolescent atomoxetine treatment. Psychopharmacology (Berl) 2017; 234:2897-2909. [PMID: 28730282 PMCID: PMC5693724 DOI: 10.1007/s00213-017-4681-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/25/2017] [Indexed: 12/17/2022]
Abstract
RATIONALE Research with the spontaneously hypertensive rat (SHR) model of attention deficit/hyperactivity disorder demonstrated that chronic methylphenidate treatment during adolescence increased cocaine self-administration established during adulthood under a progressive ratio (PR) schedule. Compared to vehicle, chronic atomoxetine treatment during adolescence failed to increase cocaine self-administration under a PR schedule in adult SHR. OBJECTIVES We determined if enhanced noradrenergic transmission at α2-adrenergic receptors within prefrontal cortex contributes to this neutral effect of adolescent atomoxetine treatment in adult SHR. METHODS Following treatment from postnatal days 28-55 with atomoxetine (0.3 mg/kg) or vehicle, adult male SHR and control rats from Wistar-Kyoto (WKY) and Wistar (WIS) strains were trained to self-administer 0.3 mg/kg cocaine. Self-administration performance was evaluated under a PR schedule of cocaine delivery following infusion of the α2-adrenergic receptor antagonist idazoxan (0 and 10-56 μg/side) directly into prelimbic cortex. RESULTS Adult SHR attained higher PR break points and had greater numbers of active lever responses and infusions than WKY and WIS. Idazoxan dose-dependently increased PR break points and active lever responses in SHR following adolescent atomoxetine vs. vehicle treatment. Behavioral changes were negligible after idazoxan pretreatment in SHR following adolescent vehicle or in WKY and WIS following adolescent atomoxetine or vehicle. CONCLUSIONS α2-Adrenergic receptor blockade in prelimbic cortex of SHR masked the expected neutral effect of adolescent atomoxetine on adult cocaine self-administration behavior. Moreover, greater efficacy of acute idazoxan challenge in adult SHR after adolescent atomoxetine relative to vehicle is consistent with the idea that chronic atomoxetine may downregulate presynaptic α2A-adrenergic autoreceptors in SHR.
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Zilkha N, Scott N, Kimchi T. Sexual Dimorphism of Parental Care: From Genes to Behavior. Annu Rev Neurosci 2017; 40:273-305. [DOI: 10.1146/annurev-neuro-072116-031447] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Noga Zilkha
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Niv Scott
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037
| | - Tali Kimchi
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
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13
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Holschbach MA, Lonstein JS. Motherhood and infant contact regulate neuroplasticity in the serotonergic midbrain dorsal raphe. Psychoneuroendocrinology 2017; 76:97-106. [PMID: 27898359 PMCID: PMC5272870 DOI: 10.1016/j.psyneuen.2016.10.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 10/03/2016] [Accepted: 10/25/2016] [Indexed: 12/22/2022]
Abstract
The adult brain shows remarkable neuroplasticity in response to hormones and the socioemotional modifications that they influence. In females with reproductive and maternal experience, this neuroplasticity includes the birth and death of cells in several forebrain regions involved in maternal caregiving and postpartum affective state. Such plasticity in midbrain sites critical for these behavioral and emotional processes has never been examined, though. By visualizing bromodeoxyuridine (BrdU) to label mitotic cells, NeuroD for neuronal precursors, and TUNEL to identify dying cells, we found that the midbrain dorsal raphe nucleus (DR, the source of most ascending serotoninergic projections) exhibited significant neuroplasticity in response to motherhood. Specifically, BrdU analyses revealed that DR newborn cell survival (but not proliferation) was regulated by reproductive state, such that cells born early postpartum were less likely to survive 12 days to reach the late postpartum period compared to cells born during late pregnancy that survived 12 days to reach the early postpartum period. Many of the surviving cells in the DR were NeuN immunoreactive, suggesting a neuronal phenotype. Consistent with these findings, late postpartum rats had fewer NeuroD-immunoreactive DR cells than early postpartum rats. Maternal experience contributed to the late postpartum reduction in DR newborn cell survival because removing the litter at parturition increased cell survival as well as reduced cell death. Unlike cytogenesis in the maternal hippocampus, which is reduced by circulating glucocorticoids, DR newborn cell survival was unaffected by postpartum adrenalectomy. These effects of reproductive state and motherhood on DR plasticity were associated with concurrent changes in DR levels of serotonin's precursor, 5-HTP, and its metabolite, 5-HIAA. Our results demonstrate for the first time that cytogenesis occurs in the midbrain DR of any adult mammal, that DR plasticity is influenced by female reproductive state and maternal experience, and that this plasticity is accompanied by changes in DR serotonergic function. Because serotonin is critical for postpartum caregiving behaviors and maternal affective state, plasticity in the DR may contribute to the neurochemical changes necessary for successful motherhood.
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Affiliation(s)
- M Allie Holschbach
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI 48824, USA.
| | - Joseph S Lonstein
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI 48824, USA
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Nephew BC. The Neurobiology of Parenting: Basic Research. Curr Behav Neurosci Rep 2016. [DOI: 10.1007/s40473-016-0059-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Klampfl SM, Brunton PJ, Bayerl DS, Bosch OJ. CRF-R1 activation in the anterior-dorsal BNST induces maternal neglect in lactating rats via an HPA axis-independent central mechanism. Psychoneuroendocrinology 2016; 64:89-98. [PMID: 26630389 PMCID: PMC4712652 DOI: 10.1016/j.psyneuen.2015.11.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/15/2015] [Accepted: 11/16/2015] [Indexed: 01/09/2023]
Abstract
Adequate maternal behavior in rats requires minimal corticotropin-releasing factor receptor (CRF-R) activation in the medial-posterior bed nucleus of the stria terminalis (mpBNST). Based on the architectural heterogeneity of the BNST and its distinct inter-neural connectivity, we tested whether CRF-R manipulation in another functional part, the anterior-dorsal BNST (adBNST), differentially modulates maternal behavior. We demonstrate that in the adBNST, activation of CRF-R1 reduced arched back nursing (ABN) and nursing, whereas activation of CRF-R2 resulted in an initial reduction in nursing but significantly increased the incidence of ABN 5h after the treatment. Following stressor exposure, which is detrimental to maternal care, ABN tended to be protected by CRF-R1 blockade. Maternal motivation, maternal aggression, and anxiety were unaffected by any manipulation. Furthermore, under basal and stress conditions, activation of adBNST CRF-R1 increased plasma ACTH and corticosterone concentrations, whereas stimulation of adBNST CRF-R2 increased basal plasma ACTH and corticosterone concentrations, but blocked the stress-induced increase in plasma corticosterone secretion. Moreover, both the CRF-R1 and -R2 antagonists prevented the stress-induced increase in plasma corticosterone secretion. Importantly, elevated levels of circulating corticosterone induced by intra-adBNST administration of CRF-R1 or -R2 agonist did not impact maternal care. Finally, Crf mRNA expression in the adBNST was increased during lactation; however, Crfr1 mRNA expression was similar between lactating and virgin rats. In conclusion, maternal care is impaired by adBNST CRF-R1 activation, and this appears to be the result of a central action, rather than an effect of elevated circulating levels of CORT. These data provide new insights into potential causes of disturbed maternal behavior postpartum.
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Affiliation(s)
- Stefanie M. Klampfl
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany
| | - Paula J. Brunton
- Division of Neurobiology, The Roslin Institute and R(D)SVS, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Doris S. Bayerl
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany
| | - Oliver J. Bosch
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany,Corresponding author. Fax: +49 941 9433052.
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Ragan CM, Harding KM, Lonstein JS. Associations among within-litter differences in early mothering received and later emotional behaviors, mothering, and cortical tryptophan hydroxylase-2 expression in female laboratory rats. Horm Behav 2016; 77:62-71. [PMID: 26219576 PMCID: PMC7005883 DOI: 10.1016/j.yhbeh.2015.07.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 07/20/2015] [Accepted: 07/22/2015] [Indexed: 12/25/2022]
Abstract
This article is part of a Special Issue "Parental Care". The effects of differential maternal care received on offspring phenotype in rodents has been extensively studied between litters, but the consequences of differential mothering within litters on offspring neurobehavioral development have been rarely examined. We here investigated how variability in maternal care received among female rat siblings (measured four times daily on postnatal days 4, 6, 8, and 10) relates to the siblings' later emotional and maternal behaviors. As previously reported, we found that some female pups received up to three times more maternal licking bouts compared to their sisters; this difference was positively correlated with the pups' body weights. The number of maternal licking bouts that females received was negatively correlated with their later neophobic behaviors in an open field during periadolescence, but positively correlated with their anxiety-related behavior in an elevated plus maze during adulthood. Licking received was also positively correlated with females' later likelihood to retrieve pups in a maternal sensitization paradigm. In addition, females' neophobia during adolescence and anxiety-related behavior during adulthood predicted some aspects of both postpartum and sensitized maternal responsiveness. Medial prefrontal cortex expression of tryptophan hydroxylase-2 (TPH2; enzyme necessary for serotonin synthesis) was negatively associated with early maternal licking received. Interestingly, cortical TPH2 was positively associated with the maternal responsiveness of sensitized virgins but negatively associated with it in postpartum females. These results indicate that within-litter differences in maternal care received is an often neglected, but important, contributor to individual differences in offspring socioemotional behaviors as well as to the cortical serotonin neurochemistry that may influence these behaviors.
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Affiliation(s)
- Christina M Ragan
- Department of Psychology and Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA.
| | - Kaitlyn M Harding
- Department of Psychology and Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA
| | - Joseph S Lonstein
- Department of Psychology and Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA
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17
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Lonstein JS, Lévy F, Fleming AS. Common and divergent psychobiological mechanisms underlying maternal behaviors in non-human and human mammals. Horm Behav 2015; 73:156-85. [PMID: 26122301 PMCID: PMC4546863 DOI: 10.1016/j.yhbeh.2015.06.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
Abstract
Maternal interactions with young occupy most of the reproductive period for female mammals and are absolutely essential for offspring survival and development. The hormonal, sensory, reward-related, emotional, cognitive and neurobiological regulators of maternal caregiving behaviors have been well studied in numerous subprimate mammalian species, and some of the importance of this body of work is thought to be its relevance for understanding similar controls in humans. We here review many of the important biopsychological influences on maternal behaviors in the two best studied non-human animals, laboratory rats and sheep, and directly examine how the conceptual framework established by some of the major discoveries in these animal "models" do or do not hold for our understanding of human mothering. We also explore some of the limits for extrapolating from non-human animals to humans. We conclude that there are many similarities between non-human and human mothers in the biological and psychological factors influencing their early maternal behavior and that many of the differences are due to species-characteristic features related to the role of hormones, the relative importance of each sensory system, flexibility in what behaviors are exhibited, the presence or absence of language, and the complexity of cortical function influencing caregiving behaviors.
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Affiliation(s)
- Joseph S Lonstein
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI 48824, USA; Department of Psychology, 108 Giltner Hall, Michigan State University, East Lansing, MI 48824, USA.
| | - Frédéric Lévy
- Physiologie de la Reproduction et des Comportements, INRA-CNRS-Université de Tours IFCE, Nouzilly 37380, France.
| | - Alison S Fleming
- Fraser Mustard Institute for Human Development, University of Toronto, Toronto, Ontario, Canada; Department of Psychology, University of Toronto at Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
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18
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Bridges RS. Neuroendocrine regulation of maternal behavior. Front Neuroendocrinol 2015; 36:178-96. [PMID: 25500107 PMCID: PMC4342279 DOI: 10.1016/j.yfrne.2014.11.007] [Citation(s) in RCA: 219] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 10/31/2014] [Accepted: 11/30/2014] [Indexed: 11/28/2022]
Abstract
The expression of maternal behavior in mammals is regulated by the developmental and experiential events over a female's lifetime. In this review the relationships between the endocrine and neural systems that play key roles in these developmental and experiential processes that affect both the establishment and maintenance of maternal care are presented. The involvement of the hormones estrogen, progesterone, and lactogens are discussed in the context of ligand, receptor, and gene activity in rodents and to a lesser extent in higher mammals. The roles of neuroendocrine factors, including oxytocin, vasopressin, classical neurotransmitters, and other neural gene products that regulate aspects of maternal care are set forth, and the interactions of hormones with central nervous system mediators of maternal behavior are discussed. The impact of prior developmental factors, including epigenetic events, and maternal experience on subsequent maternal care are assessed over the course of the female's lifespan. It is proposed that common neuroendocrine mechanisms underlie the regulation of maternal care in mammals.
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Affiliation(s)
- Robert S Bridges
- Department of Biomedical Sciences, Neuroscience and Reproductive Biology Section, Tufts University - Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA.
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Zhong J, Liang M, Akther S, Higashida C, Tsuji T, Higashida H. c-Fos expression in the paternal mouse brain induced by communicative interaction with maternal mates. Mol Brain 2014; 7:66. [PMID: 25208928 PMCID: PMC4172782 DOI: 10.1186/s13041-014-0066-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 08/25/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Appropriate parental care by fathers greatly facilitates health in human family life. Much less is known from animal studies regarding the factors and neural circuitry that affect paternal behavior compared with those affecting maternal behavior. We recently reported that ICR mouse sires displayed maternal-like retrieval behavior when they were separated from pups and caged with their mates (co-housing) because the sires receive communicative interactions via ultrasonic and pheromone signals from the dams. We investigated the brain structures involved in regulating this activity by quantifying c-Fos-immunoreactive cells as neuronal activation markers in the neural pathway of male parental behavior. RESULTS c-Fos expression in the medial preoptic area (mPOA) was significantly higher in sires that exhibited retrieval behavior (retrievers) than those with no such behavior (non-retrievers). Identical increased expression was found in the mPOA region in the retrievers stimulated by ultrasonic vocalizations or pheromones from their mates. Such increases in expression were not observed in the ventral tegmental area (VTA), nucleus accumbens (NAcc) or ventral palladium (VP). On the following day that we identified the families of the retrievers or non-retrievers, c-Fos expression in neuronal subsets in the mPOA, VTA, NAcc and VP was much higher in the retriever sires when they isolated together with their mates in new cages. This difference was not observed in the singly isolated retriever sires in new cages. The non-retriever sires did not display expression changes in the four brain regions that were assessed. CONCLUSION The mPOA neurons appeared to be activated by direct communicative interactions with mate dams, including ultrasonic vocalizations and pheromones. The mPOA-VTA-NAcc-VP neural circuit appears to be involved in paternal retrieval behavior.
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Affiliation(s)
| | | | | | | | | | - Haruhiro Higashida
- Kanazawa University Center for Child Mental Development, Kanazawa, Japan.
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Benedetto L, Pereira M, Ferreira A, Torterolo P. Melanin-concentrating hormone in the medial preoptic area reduces active components of maternal behavior in rats. Peptides 2014; 58:20-5. [PMID: 24893251 DOI: 10.1016/j.peptides.2014.05.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/16/2023]
Abstract
Melanin-concentrating hormone (MCH) is an inhibitory neuropeptide mainly synthesized in neurons of the lateral hypothalamus and incerto-hypothalamic area of mammals that has been implicated in behavioral functions related to motivation. During lactation, this neuropeptide is also expressed in the medial preoptic area (mPOA), a key region of the maternal behavior circuitry. Notably, whereas MCH expression in the mPOA progressively increases during lactation, maternal behavior naturally declines, suggesting that elevated MCHergic activity in the mPOA inhibit maternal behavior in the late postpartum period. To explore this idea, we assessed the maternal behavior of early postpartum females following bilateral microinfusions of either MCH (50 and 100 ng/0.2 μl/side) or the same volume of vehicle into the mPOA. As expected, females receiving 100 ng MCH into the mPOA exhibited significant deficits in the active components of maternal behavior, including retrieving and nest building. In contrast, nursing, as well as other behaviors, including locomotor activity, exploration, and anxiety-like behavior, were not affected by intra-mPOA MCH infusion. The present results, together with previous findings showing elevated expression of this neuropeptide toward the end of the postpartum period, suggest that modulation of mPOA function by MCH may contribute to the weaning of maternal responsiveness characteristic of the late postpartum period.
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Affiliation(s)
- Luciana Benedetto
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Mariana Pereira
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, USA
| | - Annabel Ferreira
- Sección de Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
| | - Pablo Torterolo
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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Klampfl SM, Brunton PJ, Bayerl DS, Bosch OJ. Hypoactivation of CRF receptors, predominantly type 2, in the medial-posterior BNST is vital for adequate maternal behavior in lactating rats. J Neurosci 2014; 34:9665-76. [PMID: 25031406 PMCID: PMC4099544 DOI: 10.1523/jneurosci.4220-13.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 06/05/2014] [Accepted: 06/11/2014] [Indexed: 11/21/2022] Open
Abstract
Maternal behavior ensures the proper development of the offspring. In lactating mammals, maternal behavior is impaired by stress, the physiological consequence of central corticotropin-releasing factor receptor (CRF-R) activation. However, which CRF-R subtype in which specific brain area(s) mediates this effect is unknown. Here we confirmed that an intracerebroventricularly injected nonselective CRF-R antagonist enhances, whereas an agonist impairs, maternal care. The agonist also prolonged the stress-induced decrease in nursing, reduced maternal aggression and increased anxiety-related behavior. Focusing on the bed nucleus of the stria terminalis (BNST), CRF-R1 and CRF-R2 mRNA expression did not differ in virgin versus lactating rats. However, CRF-R2 mRNA was more abundant in the posterior than in the medial BNST. Pharmacological manipulations within the medial-posterior BNST showed that both CRF-R1 and CRF-R2 agonists reduced arched back nursing (ABN) rapidly and after a delay, respectively. After stress, both antagonists prevented the stress-induced decrease in nursing, with the CRF-R2 antagonist actually increasing ABN. During the maternal defense test, maternal aggression was abolished by the CRF-R2, but not the CRF-R1, agonist. Anxiety-related behavior was increased by the CRF-R1 agonist and reduced by both antagonists. Both antagonists were also effective in virgin females but not in males, revealing a sexual dimorphism in the regulation of anxiety within the medial-posterior BNST. In conclusion, the detrimental effects of increased CRF-R activation on maternal behavior are mediated via CRF-R2 and, to a lesser extent, via CRF-R1 in the medial-posterior BNST in lactating rats. Moreover, both CRF-R1 and CRF-R2 regulate anxiety in females independently of their reproductive status.
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Affiliation(s)
- Stefanie M Klampfl
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany, and
| | - Paula J Brunton
- Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, United Kingdom
| | - Doris S Bayerl
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany, and
| | - Oliver J Bosch
- Department of Behavioural and Molecular Neurobiology, University of Regensburg, 93053 Regensburg, Germany, and
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22
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Ragan CM, Lonstein JS. Differential postpartum sensitivity to the anxiety-modulating effects of offspring contact is associated with innate anxiety and brainstem levels of dopamine beta-hydroxylase in female laboratory rats. Neuroscience 2014; 256:433-44. [PMID: 24161285 PMCID: PMC4097074 DOI: 10.1016/j.neuroscience.2013.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/26/2013] [Accepted: 10/09/2013] [Indexed: 12/15/2022]
Abstract
In female mammals, the postpartum period involves dramatic shifts in many socioemotional behaviors. This includes a suppression of anxiety-related behaviors that requires recent physical contact with offspring. Factors contributing to differences among females in their susceptibility to the anxiety-modulating effect of offspring contact are unknown, but could include their innate anxiety and brain monoaminergic activity. Anxiety behavior was assessed in a large group of nulliparous female rats and the least-anxious and most-anxious tertiles were mated. Anxiety was assessed again postpartum after females were permitted or prevented from contacting their offspring 4 h before testing. Levels of dopamine β-hydroxylase (DBH, norepinephrine synthesizing enzyme) and tryptophan hydroxylase-2 (TPH2, serotonin synthesizing enzyme) were measured in the brainstem and dorsal raphe, respectively. It was found that anxiety-related behavior in the two groups did not differ when dams were permitted contact with offspring before testing. Removal of the offspring before testing, however, differentially affected anxiety based on dams' innate anxiety. Specifically, dams reverted back to their pre-mating levels of anxiety such that offspring removal slightly increased anxiety in the most-anxious females but greatly lowered anxiety in the least-anxious females. This reduction in anxiety in the least-anxious females after litter removal was associated with lower brainstem DBH. There was no relationship between females' anxiety and dorsal raphe TPH2. Thus, a primary effect of recent contact with offspring on anxiety-related behavior in postpartum rats is to shift females away from their innate anxiety to a more moderate level of responding. This effect is particularly true for females with the lowest anxiety, may be mediated by central noradrenergic systems, and has implications for their ability to attend to their offspring.
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Affiliation(s)
- C M Ragan
- Department of Psychology and Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA.
| | - J S Lonstein
- Department of Psychology and Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA.
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Henschen CW, Palmiter RD, Darvas M. Restoration of dopamine signaling to the dorsal striatum is sufficient for aspects of active maternal behavior in female mice. Endocrinology 2013; 154:4316-27. [PMID: 23959937 PMCID: PMC5398593 DOI: 10.1210/en.2013-1257] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Striatal dopamine (DA) is important for motivated behaviors, including maternal behavior. Recent evidence linking the dorsal striatum with goal-directed behavior suggests that DA signaling in the dorsal striatum, not just the nucleus accumbens, could be involved in maternal behavior. To investigate this question, we tested the maternal behavior of mice with DA genetically restricted to the dorsal striatum. These mice had a mild deficit in pup retrieval but had normal licking/grooming and nursing behavior; consequently, pups were weaned successfully. We also tested a separate group of mice with severely depleted DA in all striatal areas. They had severe deficits in pup retrieval and licking/grooming behavior, whereas nursing behavior was left intact; again, pups survived to weaning at normal rates. We conclude that DA signaling in the striatum is a part of the circuitry mediating maternal behavior and is specifically relevant for active, but not passive, maternal behaviors. In addition, DA in the dorsal striatum is sufficient to allow for active maternal behavior.
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Affiliation(s)
- Charles W Henschen
- Department of Biochemistry, 1959 Northeast Pacific Street, Box 357370, University of Washington, Seattle, WA 98195.
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Smith CD, Piasecki CC, Weera M, Olszewicz J, Lonstein JS. Noradrenergic alpha-2 receptor modulators in the ventral bed nucleus of the stria terminalis: effects on anxiety behavior in postpartum and virgin female rats. Behav Neurosci 2013; 127:582-97. [PMID: 23796237 PMCID: PMC3947518 DOI: 10.1037/a0032776] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Emotional hyperreactivity can inhibit maternal responsiveness in female rats and other animals. Maternal behavior in postpartum rats is disrupted by increasing norepinephrine release in the ventral bed nucleus of the stria terminalis (BSTv) with the α2-autoreceptor antagonist, yohimbine, or the more selective α2-autoreceptor antagonist, idazoxan (Smith et al., 2012). Because high noradrenergic activity in the BSTv can also increase anxiety-related behaviors, increased anxiety may underlie the disrupted mothering of dams given yohimbine or idazoxan. To assess this possibility, anxiety-related behaviors in an elevated plus maze were assessed in postpartum rats after administration of yohimbine or idazoxan. It was further assessed if the α2-autoreceptor agonist clonidine (which decreases norepinephrine release) would, conversely, reduce dams' anxiety. Groups of diestrous virgins were also examined. It was found that peripheral or intra-BSTv yohimbine did increase anxiety-related behavior in postpartum females. However, BSTv infusion of idazoxan did not reproduce yohimbine's anxiogenic effects and anxiety was not reduced by peripheral or intra-BSTv clonidine. Because yohimbine is a weak 5HT1A receptor agonist, other groups of females received BSTv infusion of the 5HT1A receptor agonist 8OH-DPAT, but it did not alter their anxiety-related behavior. Lastly, levels of norepinephrine and serotonin in tissue punches from the BSTv did not differ between postpartum and diestrous rats, but serotonin turnover was lower in mothers. These results suggest that the impaired maternal behavior after BSTv infusion of yohimbine or idazoxan cannot both be readily explained by an increase in dams' anxiety, and that BSTv α2-autoreceptor modulation alone has little influence on anxiety-related behaviors in postpartum or diestrous rats.
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Affiliation(s)
- Carl D. Smith
- Department of Psychology & Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI USA 48824
| | - Christopher C. Piasecki
- Department of Psychology & Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI USA 48824
| | - Marcus Weera
- Department of Psychology & Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI USA 48824
| | - Joshua Olszewicz
- Department of Psychology & Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI USA 48824
| | - Joseph S. Lonstein
- Department of Psychology & Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI USA 48824
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