Behavioral and neurochemical characterization of maternal care effects on juvenile Sprague–Dawley rats Marianela Masís-Calvo a, ⁎, Andrey Sequeira-Cordero a,b , Andrea Mora-Gallegos a , Jaime Fornaguera-Trías a,c a Centro de Investigación en Neurociencias, Universidad de Costa Rica, 11501-2060, San Pedro, San José, Costa Rica b Instituto de Investigaciones en Salud, Universidad de Costa Rica, 11501-2060, San Pedro, San José, Costa Rica c Depto. De Bioquímica, Escuela de Medicina, Universidad de Costa Rica, 11501-2060, San Pedro, San José, Costa Rica HIGHLIGHTS • The effects of naturally occurring variations in maternal care on juvenile rats were studied. • Maternal care affects some anxiety-like but not depression-like behaviors. • Maternal care modified DOPAC content and 5-HT turnover in prefrontal cortex. abstract article info Article history: Received 17 October 2012 Received in revised form 29 March 2013 Accepted 17 May 2013 Available online 24 May 2013 Keywords: Maternal care Anxiety Stress response Grooming behavior Monoamines Sprague–Dawley Maternal care represents a major constituent of early life environment and has the potential to modulate critical neurobehavioral responses to stress. The aim of the present study was to determine the effects of naturally oc- curring variations in maternal care on behavioral and neurochemical responses of juvenile Sprague–Dawley rats. A group of dams were classified based on their licking behavior in high and low licking-grooming mothers. Afterwards, the male offspring was tested in a series of behavioral tests: open field test (OFT), elevated plus maze (EPM) and forced swimming test (FST). Additionally, monoamine concentrations were determined post- mortem in three brain regions: hippocampus, ventral striatum and prefrontal cortex. Our findings suggest that maternal care variations have an effect on several anxiety-related behaviors in OFT and EPM but not in depression-like behaviors in FST. Such behavioral differences could be related to an increased DOPAC con- centration and 5-HT turnover in prefrontal cortex. These evidences suggest that natural variations in maternal care modified some behavioral and neurochemical parameters related with anxiety and stress in this strain. © 2013 Elsevier Inc. All rights reserved. 1. Introduction Maternal care in mammals represents a major constituent of early life environment and its influence on individual development has been documented in murines, non-human primates, and humans [1,2]. Since 1950, several studies have suggested the role of parental care on neurodevelopment and human susceptibility to psychopathology [3–6]. Epidemiological surveys highlighted the importance of environmental components as vulnerability factors for psychiatric disorders such as de- pression [7,8]. Furthermore, studies showed that adverse environment in early stages of life, such as child abuse, has been involved in alter- ations of adult stress response and mood disorders [6,9,10]. In rodents, the quality of mother–pup interactions affects behavioral patterns relat- ed to anxiety, fear, and depression [11–17]. Animal models provided evidence that maternal care mediates a set of responses, which allows an individual to cope with stressful sit- uations [18–20]. Maternal deprivation and variations in natural mater- nal care behavior have been described as successful models to test the early maternal influence on brain development and health [21–23]. In rats, individual differences in maternal licking/grooming (LG) behavior exerted a multilevel regulation upon the physiological, morphologi- cal, cognitive, and behavioral development of pups [1,15,19,24–27]. These effects may remain until adulthood and can be transmitted to the next generations [15,19,22,28]. Natural occurring variations in maternal care cause a significant effect on the hypothalamic–pituitary–adrenal axis [29,30], spatial learn- ing and memory [31,32], brain morphology [24,33], neurotransmitter content in several brain structures [19,34], and epigenetic patterns and gene expression profiles [30,35]. Regions such as prefrontal cortex (PFC), hippocampus (HPC), and ventral striatum (VS) are also influenced by maternal care [18,24,36]. The overview above highlights the main role of maternal behavior as a relevant environmental influence on brain function. Most studies Physiology & Behavior 118 (2013) 212–217 ⁎ Corresponding author at: Centro de Investigación en Neurociencias (PIN), Universidad de Costa Rica, 11501-2060, San Pedro, Costa Rica. Tel.: +506 2511 4903. E-mail address: mary785@gmail.com (M. Masís-Calvo). 0031-9384/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.physbeh.2013.05.033 Contents lists available at SciVerse ScienceDirect Physiology & Behavior journal homepage: www.elsevier.com/locate/phb