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Krejcová LV, Bento-Torres J, Diniz DG, Pereira A, Batista-de-Oliveira M, de Morais AACL, Mendes-da-Silva RF, Abadie-Guedes R, dos Santos ÂA, Lima DS, Guedes RCA, Picanço-Diniz CW. Unraveling the Influence of Litter Size, Maternal Care, Exercise, and Aging on Neurobehavioral Plasticity and Dentate Gyrus Microglia Dynamics in Male Rats. Brain Sci 2024; 14:497. [PMID: 38790475 PMCID: PMC11119659 DOI: 10.3390/brainsci14050497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 04/30/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
This study explores the multifaceted influence of litter size, maternal care, exercise, and aging on rats' neurobehavioral plasticity and dentate gyrus microglia dynamics. Body weight evolution revealed a progressive increase until maturity, followed by a decline during aging, with larger litters exhibiting lower weights initially. Notably, exercised rats from smaller litters displayed higher body weights during the mature and aged stages. The dentate gyrus volumes showed no significant differences among groups, except for aged sedentary rats from smaller litters, which exhibited a reduction. Maternal care varied significantly based on litter size, with large litter dams showing lower frequencies of caregiving behaviors. Behavioral assays highlighted the detrimental impact of a sedentary lifestyle and reduced maternal care/large litters on spatial memory, mitigated by exercise in aged rats from smaller litters. The microglial dynamics in the layers of dentate gyrus revealed age-related changes modulated by litter size and exercise. Exercise interventions mitigated microgliosis associated with aging, particularly in aged rats. These findings underscore the complex interplay between early-life experiences, exercise, microglial dynamics, and neurobehavioral outcomes during aging.
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Affiliation(s)
- Lane Viana Krejcová
- Neurodegeneration and Infection Research Laboratory, João de Barros Barreto Universitary Hospital, Institute of Biological Sciences, Federal University of Pará, Belém 66050-160, Pará, Brazil
| | - João Bento-Torres
- Neurodegeneration and Infection Research Laboratory, João de Barros Barreto Universitary Hospital, Institute of Biological Sciences, Federal University of Pará, Belém 66050-160, Pará, Brazil
| | - Daniel Guerreiro Diniz
- Neurodegeneration and Infection Research Laboratory, João de Barros Barreto Universitary Hospital, Institute of Biological Sciences, Federal University of Pará, Belém 66050-160, Pará, Brazil
- Postgraduate Program in Oncology and Medical Sciences, João de Barros Barreto Universitary Hospital, Federal University of Pará, Belém 66075-110, Pará, Brazil
- Electron Microscopy Laboratory, Evandro Chagas Institute, Belém 66093-020, Pará, Brazil
| | - Antonio Pereira
- Neurodegeneration and Infection Research Laboratory, João de Barros Barreto Universitary Hospital, Institute of Biological Sciences, Federal University of Pará, Belém 66050-160, Pará, Brazil
| | - Manuella Batista-de-Oliveira
- Naíde Teodósio Nutrition Physiology Laboratory, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, Pernambuco, Brazil
| | | | | | - Ricardo Abadie-Guedes
- Naíde Teodósio Nutrition Physiology Laboratory, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, Pernambuco, Brazil
| | - Ângela Amâncio dos Santos
- Naíde Teodósio Nutrition Physiology Laboratory, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, Pernambuco, Brazil
| | - Denise Sandrelly Lima
- Naíde Teodósio Nutrition Physiology Laboratory, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, Pernambuco, Brazil
| | - Rubem Carlos Araujo Guedes
- Naíde Teodósio Nutrition Physiology Laboratory, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, Pernambuco, Brazil
| | - Cristovam Wanderley Picanço-Diniz
- Neurodegeneration and Infection Research Laboratory, João de Barros Barreto Universitary Hospital, Institute of Biological Sciences, Federal University of Pará, Belém 66050-160, Pará, Brazil
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Valtcheva S, Froemke RC. Neuromodulation of maternal circuits by oxytocin. Cell Tissue Res 2019; 375:57-68. [PMID: 30062614 PMCID: PMC6336509 DOI: 10.1007/s00441-018-2883-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/03/2018] [Indexed: 12/31/2022]
Abstract
Motherhood in mammals involves tremendous changes throughout the body and central nervous system, which support attention and nurturing of infants. Maternal care consists of complex behaviors, such as nursing and protection of the offspring, requiring new mothers to become highly sensitive to infant needs. Long-lasting neural plasticity in various regions of the cerebral cortex may enable the perception and recognition of infant cues, important for appropriate caregiving responses. Recent findings have demonstrated that the neuropeptide oxytocin is involved in a number of physiological processes, including parturition and lactation and dynamically shaping neuronal responses to infant stimuli as well. Here, we review experience-dependent changes within the cortex occurring throughout motherhood, focusing on plasticity of the somatosensory and auditory cortex. We outline the role of oxytocin in gating cortical plasticity and discuss potential mechanisms regulating oxytocin release in response to different sensory stimuli.
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Affiliation(s)
- Silvana Valtcheva
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Neuroscience Institute, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Department of Otolaryngology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Department of Neuroscience and Physiology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Neuroscience Institute, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Department of Otolaryngology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Department of Neuroscience and Physiology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Howard Hughes Medical Institute Faculty Scholar, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
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Viana L, Lima C, Oliveira M, Borges R, Cardoso T, Almeida I, Diniz D, Bento-Torres J, Pereira A, Batista-de-Oliveira M, Lopes A, Silva R, Abadie-Guedes R, Amâncio dos Santos A, Lima D, Vasconcelos P, Cunningham C, Guedes R, Picanço-Diniz C. Litter size, age-related memory impairments, and microglial changes in rat dentate gyrus: Stereological analysis and three dimensional morphometry. Neuroscience 2013; 238:280-96. [DOI: 10.1016/j.neuroscience.2013.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/12/2013] [Accepted: 02/12/2013] [Indexed: 10/27/2022]
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Stern JM, Azzara AV. Thermal control of mother-young contact revisited: hyperthermic rats nurse normally. Physiol Behav 2002; 77:11-18. [PMID: 12213497 DOI: 10.1016/s0031-9384(02)00798-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Morphine (MOR) is known to inhibit maternal behavior and induce hyperthermia; at appropriate doses, concurrent administration of naloxone (NAL) counteracts its disruption of maternal behavior but not the hyperthermia. We used these findings to evaluate the view that lactating rats terminate nursing due to intolerable hyperthermia. After a dam-litter separation of 4 h on Day 7 postpartum (PP), mother-litter interactions were observed continuously for 1 h. One hour before reunion, the dams received two injections (1 ml/kg ip each) of saline (SAL), MOR (20 mg/kg) and/or NAL (1 mg/kg) in the following combinations (n = 7 each): SAL + SAL, SAL + NAL, MOR + SAL or MOR + NAL. MOR profoundly disrupted maternal behavior, thereby preventing litter weight gains; these effects were completely counteracted by NAL, which alone had no discernible effects. In contrast, MOR-induced hyperthermia (approximately 0.7 degrees C increase in each hour, before and after reunion with pups) was not antagonized by NAL at the doses used. Thus, an additional 0.7-1.4 degrees C of body temperature (T) did not delay the onset or reduce the duration of nursing compared with SAL-treated controls. Further, there were no group differences in behaviors displayed both shortly before and after a nursing bout that included milk ejections or in the resumption of nursing. Together with earlier methodological and empirical criticisms of the thermal control theory, as well as knowledge about the somatosensory determinants of nursing, the present results suggest that nursing bouts in lactating rats are not limited by the mother's T.
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Affiliation(s)
- Judith M Stern
- Department of Psychology, Rutgers University, New Brunswick, NJ 08903, USA.
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Fleming AS, Kraemer GW, Gonzalez A, Lovic V, Rees S, Melo A. Mothering begets mothering: the transmission of behavior and its neurobiology across generations. Pharmacol Biochem Behav 2002; 73:61-75. [PMID: 12076725 DOI: 10.1016/s0091-3057(02)00793-1] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Early experiences exert their effects on adult parental behavior in part by altering the development of neurobiological mechanisms that initiate or support the initiation and sustenance of adult parental behavior. The effects of parental behavior on sensory, perceptual and emotional mechanisms in offspring constitute an experientially based mechanism by which neurobiological factors regulating behavior can be transferred from generation to generation somewhat independently of genetic endowment.
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Affiliation(s)
- Alison S Fleming
- Department of Psychology, Erindale College, University of Toronto at Mississauga, Mississauga, Ontario, Canada.
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Stern JM, Keer SE. Acute hunger of rat pups elicits increased kyphotic nursing and shorter intervals between nursing bouts: implications for changes in nursing with time postpartum. J Comp Psychol 2002; 116:83-92. [PMID: 11926687 DOI: 10.1037/0735-7036.116.1.83] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Earlier findings, based on limited behavioral observations, indicate that nursing behavior in rats declines dramatically in duration over time postpartum-despite increasing ingestion of milk by rat pups to meet their growth and metabolic needs-although hungry pups elicit more nursing than do well-nourished pups. The authors compared the nursing pattern in detail for 6 hr on Days 7 and 14 and induced hunger in pups acutely with mammary-duct-ligated dams unable to provide milk. Compared with Day 7, on Day 14, supine nursing and the interval between nursing bouts increased, whereas hovering over pups and kyphotic nursing decreased. When pups were increasingly hungry, these age-related changes were counteracted. Thus, the ingestive motivation of pups largely regulates the nursing pattem over time.
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Affiliation(s)
- Judith M Stern
- Department of Psychology, Rutgers, The State University of New Jersey, Piscataway 08854-8020, USA.
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Abstract
The supine nursing posture, which occurs increasingly as growing pups initiate nursing from their recumbent dam, was demonstrated to require more space than that provided in earlier studies of mother-young contact (e.g., Leon, Croskerry, & Smith, 1978). Further, hyperthermic rat pups were shown to be deficient in eliciting normal nursing behavior. During a 4-hr separation from their dam, 7-day-old rat pups were incubated at 34 degrees C (nest temperature) or at 39 degrees C (WARM). Compared to controls, WARM-litter dams showed increased licking of and hovering over pups and decreased upright crouching, while WARM litters showed decreased nipple attachment and weight gain. On Day 13, similar effects occurred after incubation at 39 degrees C (vs. 34 degrees C), but not at 36 or 38 degrees C. The results stress the need for ethologically meaningful conditions and direct behavioral observations to reveal the importance of pup activity in the mother-young dyad.
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Affiliation(s)
- J M Stern
- Department of Psychology, Rutgers--The State University of New Jersey, New Brunswick, USA
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Jans JE, Woodside BC. Nest temperature: effects on maternal behavior, pup development, and interactions with handling. Dev Psychobiol 1990; 23:519-34. [PMID: 2272408 DOI: 10.1002/dev.420230607] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
These studies compared the patterns of mother-young contact under different thermal environments and assessed the implications of the differing patterns of contact for pup development and the dam's behavior. In the first experiment, the warm surface dramatically reduced the total amount of contact time between dams and litters and the dam's food intake, but the effects on the pups were limited to smaller adrenal glands. A replication of the first experiment in which daily weighing and handling of the pups was eliminated produced no differences in development. In a third experiment, during which dams had access to a warm surface outside of the next area and the daily weighing and handling was resumed, the pups showed smaller adrenal glands, lower body temperatures and less thermoregulatory ability. A comparison of results suggests that handling increased the weight of adrenal glands of pups reared under the unmanipulated condition, but not the warm-rearing condition.
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Affiliation(s)
- J E Jans
- Psychology Department, Concordia University, Montreal, Quebec, Canada
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Stern JM, Johnson SK. Ventral somatosensory determinants of nursing behavior in Norway rats. I. Effects of variations in the quality and quantity of pup stimuli. Physiol Behav 1990; 47:993-1011. [PMID: 2388953 DOI: 10.1016/0031-9384(90)90026-z] [Citation(s) in RCA: 219] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
By varying the quality and quantity of tactile input that rat dams, between Days 2 and 14 postpartum, received from their pups, we found the following: a) After a 4-hr separation from their litter, mothers continuously display an array of activities, until the onset of nursing, in response to displaced pups and to pups gathered in the nest. b) While the dam hovers over the gathered pups, engaged in an activity such as pup-licking, the young gain access to the dam's ventrum and root for a nipple. c) Pups capable of effective rooting, nipple attachment, and suckling thereby stimulate the dam's immobility (i.e., inhibition of head and limb movements), assumption of the upright crouching posture, and milk ejections. d) Rat dams do not become immobile or crouch in response to pups that are inactive or that are active but incapable of rooting effectively or suckling. e) The likelihood and speed of assuming the quiescent nursing posture, as well as of having milk ejections subsequently, are directly related to the number of effective pups in the nest. We propose that the initiation, maintenance and termination of nursing behavior are related to the spatial and temporal summation of effective ventral somatosensory afferents.
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Affiliation(s)
- J M Stern
- Department of Psychology, Rutgers University, New Brunswick, NJ 08903
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Hofer MA, Zmitrovich A, Shair HN. Nursing interaction of Wistar rats is modified by prior experience of altered nursing bout length. Dev Psychobiol 1989; 22:321-45. [PMID: 2721816 DOI: 10.1002/dev.420220402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We tested the capacity of 2 week postpartum Wistar rat litters and their dams to adapt to experimental shortening and lengthening of the time available for nursing while maintaining the frequency of bouts constant, using manual transfer between cage compartments. In 8-hr and 24-hr experiments, the short bout group (10 min/hr) gradually came to show normal litter weight gain, short latency milk ejections, and increased high arched nursing position, while the 40-min/hr group showed increased latency to attachment and longer latency to ME compared to the 20 min/hr control group. Pup body temperature did not vary between groups. Although pups in the 10-min group showed increased dam-directed behaviors in the first 8h, this difference vanished thereafter. In a twenty-fifth cycle, after dams and litters were exchanged, the prior experiences of the dams and not of the litters were found to determine the dynamics of milk exchange.
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Affiliation(s)
- M A Hofer
- Department of Psychiatry, Columbia University, New York, New York
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