The Effect of Maternal Care on Social Behavior Across the Estrous Cycle Amanda P. Borrow a , Liza R. Moscovice b , and Nicole M. Cameron ab a Psychology Department, SUNY Binghamton, Binghamton, NY, USA, 13902 b Biology Department, SUNY Binghamton, Binghamton, NY, USA, 13902 Introduction Maternal care impacts sex hormone levels and estrous cycling in the rat, with low levels of maternal care predict a higher surge of progesterone during proestrus and a longer estrous cycle1.Hormonal changes across the estrous cycle have been shown to alter female behavior2,3. However, there is little research on the effect of the estrous cycle on social behavior, especially in the rat. As our lab has witnessed behavior changes in cycling females, we wished to investigate the magnitude of our observations. Since previous findings suggest a role for maternal care variation on estrous cycling, it is possible that maternal care mediates behavioral changes associated with day of cycle as well. Furthermore, as oxytocin is well-linked to affiliative behavior4, and oxytocin receptor expression is greater in High and Low LG females5, we hypothesize that maternal care will influence both affiliative behavior across the estrous cycle and peripheral oxytocin levels. Methods Maternal Observations Dams were observed every three minutes 5 times a day during PND 1-6. Females displaying LG levels 1 SD above the mean were categorized as High LG; females 1 SD below the mean were categorized as Low LG. Offspring were weaned at 21 days of age and utilized for this experiment in adulthood. Social Behavior Observations High LG (n=14) and Low LG (n=12) females pairhoused with same-sex littermates were smeared daily to determine estrous cycle. One female was designated the “focal” in each cage. Social behavior was observed in 30 minute bouts under red light when focal was in proestrus, estrus, and diestrus. Oxytocin Assay Tail blood was collected to assess baseline levels. An EIA was run on the plasma using an Enzo LifeScience kit. Summary •Same-sex social behavior varies across the estrous cycle •Maternal care influences these variations in behavior •Maternal care does not affect basal oxytocin levels in female rats •Oxytocin may be associated with variations in behavior across the estrous cycle Conclusions Although maternal care doesn’t influence basal oxytocin levels, it does affect the display of affiliative behavior in the rat across the estrous cycle. References 1. Cameron N.M. et al. PLoS ONE 2008; 3(5):e2210 2. Schneider T., Popik P. Psychoneuroendocrinology 2007; 32(6):651-9 3. Chen W. et al. Behav Brain Res; 201(1):8-13 4. Stein D.J. CNS Spectr 2009; 14(11):602-6 5. Francis D.D. et al. J Neuroendocrinol 2000; 12(12): 1145-8 Figure 1. Related-samples Wilcoxon Signed Rank test revealed that grooming received was lower during proestrus than in estrus in Lows (p=.028) and Highs (p=. 043) Figure 2. Related-samples Wilcoxon Signed Rank test revealed that rough and tumble play was significantly less frequent in Lows during metestrus vs. proestrus (p=.041) or estrus (p=.027) * 0 1 2 3 4 5 6 7 8 9 Proestrus Estrus Oxytocin (pg/mL) Estrous Day Oxytocin Across the Estrous Cycle Figure 4. Regression analysis showed that estrous cycle is predictive of basal oxytocin levels (p=.03). An ANOVA revealed that oxytocin levels trended towards being higher during proestrus than metestrus (p=.055). Figure 3. Related-samples Wilcoxon Signed Rank test revealed that mounting received during proestrus was greater than during estrus (p=.026) or metestrus (p=. 026) in Highs only * * * Diestrus Diestrus Diestrus Diestrus

The Effect of Maternal Care on Social Behavior Across … Effect of Maternal Care on Social Behavior Across the Estrous Cycle! Amanda P. Borrowa, ... Furthermore, as oxytocin is well-linked

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Page 1: The Effect of Maternal Care on Social Behavior Across … Effect of Maternal Care on Social Behavior Across the Estrous Cycle! Amanda P. Borrowa, ... Furthermore, as oxytocin is well-linked

wqe4xxxx The Effect of Maternal Care on Social Behavior Across

the Estrous Cycle!Amanda P. Borrowa, Liza R. Moscoviceb

, and Nicole M. Cameronab!!aPsychology Department, SUNY Binghamton, Binghamton, NY, USA, 13902

bBiology Department, SUNY Binghamton, Binghamton, NY, USA, 13902

Introduction!!Maternal care impacts sex hormone levels and estrous cycling in the rat, with low levels of maternal care predict a higher surge of progesterone during proestrus and a longer estrous cycle1.Hormonal changes across the estrous cycle have been shown to alter female behavior2,3. However, there is little research on the effect of the estrous cycle on social behavior, especially in the rat. As our lab has witnessed behavior changes in cycling females, we wished to investigate the magnitude of our observations. Since previous findings suggest a role for maternal care variation on estrous cycling, it is possible that maternal care mediates behavioral changes associated with day of cycle as well. Furthermore, as oxytocin is well-linked to affiliative behavior4, and oxytocin receptor expression is greater in High and Low LG females5, we hypothesize that maternal care will influence both affiliative behavior across the estrous cycle and peripheral oxytocin levels. !

Methods!Maternal Observations!Dams were observed every three minutes 5 times a day during PND 1-6. Females displaying LG levels 1 SD above the mean were categorized as High LG; females 1 SD below the mean were categorized as Low LG. Offspring were weaned at 21 days of age and utilized for this experiment in adulthood.!

Social Behavior Observations!High LG (n=14) and Low LG (n=12) females pairhoused with same-sex littermates were smeared daily to determine estrous cycle. One female was designated the “focal” in each cage. Social behavior was observed in 30 minute bouts under red light when focal was in proestrus, estrus, and diestrus.!

Oxytocin Assay!Tail blood was collected to assess baseline levels. An EIA was run on the plasma using an Enzo LifeScience kit.!!!!

Summary!• Same-sex social behavior varies across the estrous cycle!• Maternal care influences these variations in behavior!• Maternal care does not affect basal oxytocin levels in female rats!• Oxytocin may be associated with variations in behavior across the estrous cycle!!Conclusions!Although maternal care doesn’t influence basal oxytocin levels, it does affect the display of affiliative behavior in the rat across the estrous cycle.!!!!!!!!!!!!References!!1.  Cameron N.M. et al. PLoS ONE 2008; 3(5):e2210!2.  Schneider T., Popik P. Psychoneuroendocrinology

2007; 32(6):651-9!3.  Chen W. et al. Behav Brain Res; 201(1):8-13!4.  Stein D.J. CNS Spectr 2009; 14(11):602-6!5.  Francis D.D. et al. J Neuroendocrinol 2000; 12(12):

1145-8!!

Figure 1. Related-samples Wilcoxon Signed Rank test revealed that grooming received was lower during proestrus than in estrus in Lows (p=.028) and Highs (p=.043) !

Figure 2. Related-samples Wilcoxon Signed Rank test revealed that rough and tumble play was significantly less frequent in Lows during metestrus vs. proestrus (p=.041) or estrus (p=.027) !

Proestrus Estrus Metestrus

Oxy

toci

n (p

g/m

Estrous Day

Oxytocin Across the Estrous Cycle

Figure 4. Regression analysis showed that estrous cycle is predictive of basal oxytocin levels (p=.03). An ANOVA revealed that oxytocin levels trended towards being higher during proestrus than metestrus (p=.055).!

Figure 3. Related-samples Wilcoxon Signed Rank test revealed that mounting received during proestrus was greater than during estrus (p=.026) or metestrus (p=.026) in Highs only!

* *

Diestrus!Diestrus!

Diestrus!