Primary reactions to salient stimuli can be categorized as Approach and Avoidance (A/A) behaviors.
The term Approach regards to the behavioral orientation toward positive stimuli, while Avoidance regards to the tendency to move away from negative stimuli. A/A conflict arises when a stimulus exhibits desirable and aversive features, simultaneously.
Spontaneous individual differences in the A/A responses to conflicting stimuli occur among species and strains, and even within the same population, depending on the interaction between life experiences and specific neurobiological substrate of single individuals. By using A/A Y-Maze test we have previously characterized three A/A phenotypes within inbred C57Bl6 mice. Our preliminary data indicate that parents' A/A phenotype influences offspring's behavior, although the mechanism that modulates this influence has not yet been clarified.
The aim of the present project is to examine the intergenerational effects of maternal and paternal A/A phenotype on (bi)parental care and on offspring's A/A behavior and anxiety. Furthermore, we will perform immunohistochemical analyses on parents' and offspring's receptors of oxytocin (OXTR) and expression of arginine vasopressin (AVP) and galanin (Gal), in medial preoptic area of hypothalamus (mPOA), bed nucleus of stria terminalis (BNST), lateral septum, amygdala and prefrontal cortex, structures strongly involved in triggering and modulating parental care and A/A circuitry.
We expect that maternal and paternal A/A phenotype is related to the expression of OXTR, AVP, Gal and differently affects parental care and offspring's performances in the A/A Y-Maze, Open Field (OF) and Elevated Plus Maze (EPM).
Uncovering the early mechanisms and intergenerational influence of A/A behaviors appears to be decisive for managing and preventing negative outcomes.
Although in the past the research on excessive Approach and Avoidance behaviors has helped in characterizing their role in the development of psychopathologies as depression, substance abuse, anxiety and post-traumatic stress disorder, and in investigating neuronal substrates of these susceptibilities (1, 2), the intergenerational influences of A/A phenotypes from parents to offspring have not yet been analyzed.
The present project will allow promoting further knowledge on the mechanisms of transmission of the different phenotypes, and revealing the neurobiological mechanisms underlying these influences.
In addition, since this project requires the formation of couples exhibiting different BA/AP/AV phenotypes and the (bi)parental care of the offspring until weaning, it will also allow an analysis of the paternal contribution, historically underestimated, to such intergenerational influences.
The investigation of Gal expression, in addition to oxytocin and arginine vasopressin, will also extend our knowledge on the neuromodulators of parental care for both mothers and fathers (3).
Despite recent steps forward the characterization of (bi)parental behavior have been made, further investigations are needed for investigating the social mechanisms put into action by mothers and fathers in breeding the pups. The (bi)parental care observation and (bi)parental retrieval (4, 5) represent procedures for examining the maternal and paternal intergenerational effects on pups, both separately and concurrently (6).
Bibliography:
1. Kaldewaij et al., (2017) Curr. Top Behav. Neurosci.; 30:275-293
2. Aupperle and Paulus, (2010) Dialogues Clin. Neurosci.; 12(4):517-531
3. Bales and Saltzman, (2016) Horm. Behav.; 77:249-259
4. Orefice and Heinrichs, (2008) Epilepsy Behav.; 12(2):234-241
5. Liu et al., (2013) Nat. Commun.; 4:1346
6. Dulac et al., (2014) Science.; 345(6198):765-770