Our lab has 2 primary research programs. The first research area examines the neural and behavioral features of circadian rhythms in the day-active Octodon degus, an animal model with circadian properties similar to humans. Currently, we are particularly interested in the post-pubertal development of sex differences in the use of photic and non-photic entraining cues, and the anatomical system supporting the use of each type of entraining signal. We also examine the process of reentrainment after a shift of the light cycle (jetlag), and the effects of circadian shifts on the stress axis and sleep.

The interest in non-photic entrainment has led to a recent discovery that tasks that require a high degree of attention can lead to major alterations in the timing of circadian activity, and we are pursuing the hypothesis that these changes are dependent upon acetylcholine (ACh) projections to the suprachiasmatic nucleus (SCN).

Our second area of research is the neural and behavioral expression of sex differences. We explore this through research examining the development of complex social behaviors over the first 2 years of life in sheep. Behavioral and physiological consequences of prenatal steroid hormone exposure are studied in animals from birth through the end of the second breeding season when brains are collected. The goal of this study is to better understand the interaction between prenatal biological factors and postnatal life history events in the display of adult behaviors.

• What causes jet lag and how can I get over it faster?
• Why can't I get up for my 9am class?
• How do experiences during puberty alter the brain for life?
• What happens to sleep during times of stress?
• Is the body's internal clock important for reproduction in all species?

These are just a few of the questions our lab is working to answer about the body's internal clock. We currently work with the diurnal degu and the nocturnal rat to better understand the functioning of the internal clock, sleep, and reproduction.

Past research has demonstrated that circadian rhythm function is not mature in the diurnal Octodon degu until 12 months of age, 7 months after puberty. Current research is now examining the effects of gonadal hormones on the maturing circadian system just before and during early puberty. Our lab is also examining sex differences and the effects of prenatal stress on adolescent rat circadian rhythms and whether or not they are relatively insensitive to light exposure during the pubertal period.

Given adolescent circadian disruptions, our lab is now looking at the effect these may have on reproductive function in female rats as well as circadian control of reproductive function in degus.

Our lab is also in the midst of exciting research pertaining to shift-work and jet-lag, examing the effects of attention-tasks on chronotype and differences in male and female sleep, juvenile sleep, and response to jet-lag treatments.
Learn more...

• How do male and female brains differ?
• Can environmental toxins alter reproduction?
• Is sexuality in animals always clearly masculine or feminine?
• Are females better at social recognition?

We are currently studying these questions and others about gender-specific behavior and how it can be affected by pre-natal exposure to hormones or environmental variables.

Our lab generates female (XX chromosome) sheep with varying degrees of virilization for the purpose of studying the developmental components of the hypothalamic/pituitary/gondal axis. We also have created XY sheep with varying amounts of masculinization blocked. They are ideal animals for examining the effects of intersexual external and internal phenotypes on behavior.
Learn more...

Our lab works with the Octodon degu. This diurnal rodent is optimal for studying circadian behavior as well as for studying reproductive behavior since the degu estrous cycle is much more similar to the human menstrual cycle than the rat estrous cycle. Although not many labs work with this animal, we have developed care regimens and techniques for working successfully with these animals to produce meaningful scientific results.

We also work with sheep to study internal and external intersex phenotypes. Such work has only been done in the past with completely virilized rodents and a small number of studies with primates. As such, we have developed protocols and techniques that may be useful to others interested in this line of research.
Learn more...

Research opportunities with the Lee Lab are available through Psych 326, 338, 331, 422, senior honors thesis courses, SROP and others. Please contact Dr. Lee for more information.

Other courses that may be of interest include:

• UROP: Brain and behavioral mechanisms underlying circadian rhythms: Research objectives:
  • Examining the interaction of attention tasks with circadian rhythms, particularly the effect of “night shift-work” (working/attention at times of rest) on behavioral rhythms.
  • Determining the organization of the brain which allows the circadian mechanism to control the timing of hormone release and behaviors.
  • General laboratory assistance including maintenance of the degu colony.
• UROP: Sheep as a model for gender identity development: Gender identity can be determined in animal models by examining the behavior of the animals under a variety of circumstances. The development of gender is being studied in sheep that were exposed to testosterone or a control substance during part of gestation to determine the effects of prenatal hormones on this complex set of behaviors. Because sheep take 6 months to reach maturity, and because they live in complex social groups, their gender identity, like that of humans, is a combination of biological and social experiences.
• Psych 328: Research Lab for Psychology as a Natural Science: Offers an opportunity to integrate experiential and academic work within the context of a field setting. Students make their own arrangements to work in a psychology research lab; meet regularly with a faculty sponsor and research group to discuss their experiences; read materials which are relevant to the research topic and techniques being used; and create some form of written product that discusses the research and the student's participation in the research process.
• Psych 331: Laboratories in Biopsychology: The purpose of this course is three-fold: (1) to provide practical laboratory experience by assisting an individual faculty member (2) to introduce selected general methods used in the field of biopsychology or cognitive science; (3) to provide practical knowledge about research design, quantification of behavior, scientific writing, the use of animals in research, and miscellaneous techniques used by biopsychologists or cognitive scientists in laboratory research. Specific instructions and an application form (which must be completed) are available in the Psychology Undergraduate Office (1343 East Hall) or the Biopsychology Program Office (4029 East Hall).
• Psych 435: Biological Rhythms and Behavior: Examines circadian and seasonal behavior and physiology from a variety of viewpoints: adaptive importance, functional properties, and neural/hormonal mechanisms that are involved in generating cycles. We explore the role of rhythms in physiology, behavior, and disorders such as jet lag and insomnia.
• Psych 438: Hormones and Behavior: Do hormones influence behavior? Yes. Hormones can have a profound effect on the brain and this can produce changes in behavior. Hormone-brain-behavior relations in humans, dogs, rats, frogs, moths, and other animals will be the topics of discussion. Behaviors to be discussed include sex differences in the brain, as well as hormonal influences on mating behavior, courtship behavior, parental behavior, aggression, thirst, feeding, cognitive functions, and stress responses. Grades will be based on the results of three exams.
• Psych 532: Mammalian Reproductive Endocrinology: Offered only during the winter term, this class is a study of the physiological and behavior actions for reproductive hormones, which are responsible for the regulation of the reproductive systems and behavior. Topics include: The properties and mechanisms of action of pituitary gonadotropin and sex steroid hormones, the anatomy and endocrine regulation of the reproductive tracts (reproductive and maternal behavior), mechanisms of fertilization, implantation and development, the (neuro) endocrinology of mating and maternal behavior, pregnancy, and contraception.
• Psych 533: Sleep: Neurobiology, Medicine, and Society: The objective of this course is to give students the most up-to-date information on the biological, personal, and societal relevance of sleep. The brain actively generates sleep, and the first third of the course will overview the neurobiological basis of sleep cycle control. The second third of the class will cover sleep-dependent changes in physiology and sleep disorders medicine. The societal relevance of the sleep will be considered in the final portion of the class. Fulfillment of course objectives will be quantified by pre- versus post-class informational self-evaluation. In-class arousal levels will be facilitated by seminar participation.

Useful Links:

• Course Guide
• Department of Psychology
• Psychology Graduate Program
• Psychology Undergraduate Program