KRISTIN M. KRAMER, Ph.D.

Assistant Professor

Ph.D., University of Minnesota

Department of Biology

Life Sciences 531

Phone: (901) 678-2985

Fax: (901) 678-4457

email: kkramer1@memphis.edu

 


Research Interests:

What creates a social mammal?  Why are some species of mammals monogamous?  What hormones regulate positive social behavior and sexual behavior?  What neuroanatomical features facilitate social behavior?  How do those features arise within individuals or within a species?

 

My research program addresses these questions using two different groups of rodents as a model system.  Most of my work has been done with prairie voles (Microtus ochrogaster) and other Microtus species.  I also do some comparative work using deer mice (Peromyscus maniculatus) and California mice (P. californicus).  I am interested in the neuroendocrine regulation of positive social behaviors such as affiliation in mammals.  In particular, I study the effects of the neuropeptides oxytocin and vasopressin on social behavior.  Additionally, I am interested in the interaction between neuropeptides and estrogen receptor a and its importance for social behavior.  One way I have addressed this is by manipulating neuropeptides and examining animals for changes in estrogen receptor a.  Future work will involve the use of a viral vector to increase or decrease estrogen receptors in particular brain regions.   In addition to trying to understand the mechanisms that facilitate or inhibit social behavior, I am also interested in how those mechanisms arise.  Primarily, I have examined the role of hormones during developmental periods on social behavior in adulthood and on the underlying neuroendocrine mechanisms.  One approach I have used is to treat animals with oxytocin early in life and examine animals for alterations in social behavior.  This has implications for human health, as the synthetic form of oxytocin is used in the majority of hospital deliveries and may have the potential to affect neural development of the infant.  Future work will address the possibility that the social environment early in life plays a role in determining social behavior in adulthood. 

 

I am also interested in an evolutionary approach.  Monogamy is a rare social system in mammals with only ~ 3-5% of mammals being classified as monogamous.  A secondary aspect of my research program involves comparative studies and manipulations to better understand the evolution of neuroendocrine systems involved in monogamy.

 


 

Selected Publications

 

 

Kramer KM, Choe C, Carter CS, Cushing BS. 2005. Developmental effects of oxytocin on neural activation and neuropeptide release in response to social stimuli.  Hormones and Behavior.  In press.

 

Cushing BS, Kramer KM. 2005. Mechanisms underlying epigenetic effects of early social experience: the role of neuropeptides and steroids.  Neuroscience and Biobehavioral Reviews 29:1089-1115.

 

Reeder DM, Kramer KM. 2005. Stress in free-ranging mammals: integrating physiology, ecology, and natural history.  Journal of Mammalogy 86: 225-235.

   

Kramer KM, Yamamoto Y, Hoffman GE, Cushing BS. 2005. Estrogen receptor a and vasopressin in the paraventricular nucleus of the hypothalamus in Peromyscus.  Brain Research 1032: 154-161.

 

Cushing BS, Kramer KM. 2005. Microtines: a model system for studying the evolution and regulation of social monogamy.  Acta Theriologica Sinica.  25:182-199.

   

Kramer KM, Cushing BS, Carter CS, Wu J, Ottinger MA. 2004. Sex and species differences in plasma oxytocin using an enzyme immunoassay.  Canadian Journal of Zoology 82:1194-1200.

 

Yamamoto Y, Cushing BS, Kramer KM, Epperson PD, Hoffman GE, Carter CS. 2004. Neonatal manipulations of oxytocin alter expression of oxytocin and vasopressin immunoreactive cells in the paraventricular nucleus of the hypothalamus in a gender-specific manner.  Neuroscience 125:947-955.

 

Kramer KM, Cushing BS, Carter CS. 2003. Developmental effects of oxytocin on stress response: single versus repeated exposure.  Physiology & Behavior 79:775-782.

 

Withuhn TF, Kramer KM, Cushing BS. 2003. Early exposure to oxytocin affects the age of vaginal opening and first estrus in female rats.  Physiology & Behavior 80:135-138.

 

Brunet AK, Zink RM, Kramer KM, Blackwell-Rago RC, Farrell SL, Line TV, Birney EC. 2002. Evidence of introgression between masked shrews (Sorex cinereus) and prairie shrews (S. haydeni) in Minnesota.  American Midland Naturalist 147:116-122.

 

Kramer KM, Birney EC. 2001. Effect of light intensity on activity patterns of Patagonian leaf-eared mice, Phyllotis xanthopygus.  Journal of Mammalogy 82:535-544.

 

Kramer KM, Sothern RB. 2001. Circadian rhythm of corticosterone secretion in red-backed voles (Clethrionomys gapperi).  Chronobiology International 18:933-945.

 

Kramer KM, Monjeau JA, Birney EC, Sikes RS. 1999. Phyllotis xanthopygus. Mammalian Species  617:1-7.

 

Kramer KM. 1998. Inexpensive motion detectors for quantification of animal activity.  BioTechniques 25:385-388.