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Zuluaga MJ, Agrati D, Athaíde V, Ferreira A, Uriarte N. Fear response of rat pups to a non-aversive social stimulus: Evidence for the involvement of memory processes. Dev Psychobiol 2023; 65:e22417. [PMID: 37860902 DOI: 10.1002/dev.22417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/20/2023] [Accepted: 08/10/2023] [Indexed: 10/21/2023]
Abstract
Learning processes in rats during early development are importantly mediated by the mother, which represents the primary source of environmental information. This study aimed to determine whether aversive early experiences can induce the expression of pups' fear responses toward a non-aversive stimulus as a consequence of a memory process. First, we determined pups' fear responses toward an anesthetized female after being exposed to this stimulus or an empty cage together with their mothers from Postnatal Day (PNDs) 1 to 4. Second, we evaluated if the administration of the protein synthesis inhibitor cycloheximide (CHX; 0.2 mg/kg, subcutaneously (sc).) disrupted the reconsolidation processes and abolished the fear response on PND 9. Only female pups previously exposed to the female intruder expressed fear responses toward an anesthetized female on PND 8. CHX administration to female pups immediately after exposure to an anesthetized female on PND 8 suppressed fear responses on PND 9, indicating that the fear expression was the result of a memory process, probably mediated by the mother. These findings demonstrated that early experiences can shape responses to social stimuli in a sex-dependent manner and emphasize the critical role of the mother in influencing fear learning in a social context.
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Affiliation(s)
- María José Zuluaga
- Biofisicoquímica, Departamento de Ciencias Biológicas, Centro Universitario Regional Litoral Norte-Sede Salto, Universidad de la República, Salto, Uruguay
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Daniella Agrati
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Vanessa Athaíde
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Annabel Ferreira
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Natalia Uriarte
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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Agrati D, Uriarte N. What can challenging reproductive contexts tell us about the rat's maternal behavior? Front Behav Neurosci 2023; 17:1239681. [PMID: 37521725 PMCID: PMC10375047 DOI: 10.3389/fnbeh.2023.1239681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 07/03/2023] [Indexed: 08/01/2023] Open
Abstract
Maternal behavior in mammals encompasses a complex repertoire of activities that ensure the survival of the offspring and shape their neural and behavioral development. The laboratory rat has been employed as a classic model for investigating maternal behavior, and recently with the use of advanced techniques, the knowledge of its neural basis has been expanded significantly. However, the standard laboratory testing conditions in which rats take care of a single litter impose constraints on the study of maternal flexibility. Interestingly, the reproductive characteristics of this species, including the existence of a fertile postpartum estrus, allow us to study maternal behavior in more complex and ethologically relevant contexts, even in laboratory settings. Here we review how maternal and sexual motivations interact during the postpartum estrus, shaping the behavioral response of females according to the presence of the pups and males. Next, we describe how impregnation during the postpartum estrus creates a new reproductive context in which mothers simultaneously care for two successive litters, adapting their responses to different behavioral and physiological demands of pups. These findings illustrate the behavioral adaptability of maternal rats to pups' needs and the presence of other reinforcers, as well as its dependence on the context. In our view, future perspectives in the field, by incorporating the use of cutting-edge techniques, should analyze maternal flexibility and its neural substrates in models that incorporate complex and challenging contexts. This approach would allow a more comprehensive understanding of brain circuits involved in the adaptive and flexible nature of parenting.
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Affiliation(s)
- Daniella Agrati
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Natalia Uriarte
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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Kan JM, Richardson R. Ghosts of mother's past: Previous maternal stress leads to altered maternal behavior following a subsequent pregnancy in rats. Dev Psychobiol 2018; 60:278-291. [DOI: 10.1002/dev.21609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 11/08/2017] [Accepted: 11/18/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Janice M. Kan
- School of Women's and Children's HealthThe University of New South WalesSydneyNew South WalesAustralia
| | - Rick Richardson
- School of PsychologyThe University of New South WalesSydneyNew South WalesAustralia
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Environmental Intervention as a Therapy for Adverse Programming by Ancestral Stress. Sci Rep 2016; 6:37814. [PMID: 27883060 PMCID: PMC5121646 DOI: 10.1038/srep37814] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 11/02/2016] [Indexed: 12/11/2022] Open
Abstract
Ancestral stress can program stress sensitivity and health trajectories across multiple generations. While ancestral stress is uncontrollable to the filial generations, it is critical to identify therapies that overcome transgenerational programming. Here we report that prenatal stress in rats generates a transgenerationally heritable endocrine and epigenetic footprint and elevated stress sensitivity which can be alleviated by beneficial experiences in later life. Ancestral stress led to downregulated glucocorticoid receptor and prefrontal cortex neuronal densities along with precocious development of anxiety-like behaviours. Environmental enrichment (EE) during adolescence mitigated endocrine and neuronal markers of stress and improved miR-182 expression linked to brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) regulation in stressed lineages. Thus, EE may serve as a powerful intervention for adverse transgenerational programming through microRNA-mediated regulation of BDNF and NT-3 pathways. The identification of microRNAs that mediate the actions of EE highlights new therapeutic strategies for mental health conditions and psychiatric disease.
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Uriarte N, Fernández MV, Agrati D, Zuluaga MJ, Ferreño M, Ferreira A. Maternal and affective behaviors of lactating rats reared in overlapping litters. ACTA ACUST UNITED AC 2014; 108:221-30. [PMID: 24746748 DOI: 10.1016/j.jphysparis.2014.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/26/2014] [Accepted: 04/02/2014] [Indexed: 02/08/2023]
Abstract
Postpartum mating in rats gives rise to complex family units consisting of the mother and two overlapping litters. As a consequence, newborn pups of the second litter, since the moment they are born, acquire experience not only from interaction with the mother and age-matched littermates but also from interaction with older siblings. Newborn pups reared in overlapping litters (OLs) receive a different pattern of maternal stimulation compared to those reared in single litters (SL: one litter of same aged pups), as the mothers reduce some maternal behavior components and juvenile pups from the first litter develop maternal behavior. Since there is strong evidence showing that variations in maternal behavior are transmitted throughout generations, we hypothesized that the altered pattern of maternal stimulation received by OL reared females would modify their behavior during motherhood. To test this hypothesis maternal behavior, maternal aggression and experimental anxiety of dams reared under OL and SL conditions during the first postpartum week were compared. No differences were found between the groups in their maternal behavior and aggression. This result may be explained by the maternal behavior of the juveniles that could compensate for the deficits in the caregiving behaviors received by OL litters. However, a subtle temporal reorganization of the licking behavior was found in OL reared mothers, together with an increased anxiety-related behavior in the plus maze test. These results suggest dissociation in the effects provoked by early environmental alterations on different behavioral systems, and more importantly, that independently of their early family composition, both groups can cope effectively with the changing demands of the pups.
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Affiliation(s)
- Natalia Uriarte
- Laboratorio de Neurociencias, Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
| | - María Victoria Fernández
- Laboratorio de Neurociencias, Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Daniella Agrati
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay
| | - María José Zuluaga
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Marcela Ferreño
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Annabel Ferreira
- Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay
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