Women's Health
Women's mental health is an important issue to those interested in how subject factors influence stress responses, the ability to cope with stress, and the development of certain abnormal behaviors.
Why is women's health, particularly mental health, becoming a larger issue in the medical community?
Many health issues are more or less common in men versus women. In the area of neurobehavioral disorders, women are 2-3 times more likely to experience a significant anxious or depressive condition in their lifetime compared to men. Depression and anxiety disorders also happen to be the two most common psychological disorder classes in the United States. Thus, studies of the causes and treatments of these conditions should take into account the female psychobiology when developing the most efficient means by which to treat these conditions. More information concerning advocating women's health research in general can be found at the Society for Women's Health Research (http://www.womenshealthresearch.org).
Stress and women's health: How we are researching this issue?
Ovarian Hormone Regulation of Sensory Reactivity: Our laboratory has been documenting how ovarian hormones (estrogen and progesterone) affect sensory reactivity through the use of the acoustic startle response reflex.
- In women, we have found increased startle reactivity in women using oral contraceptives. This affect appears most robust during the later phases of the menstrual cycle (when the hormone treatments are being ingested - not the placebo pills).
- In rats, we have found that painful stressors cause a reduction in startle reactivity preferentially in female rats. This suppressed startle response is apparent at least 2 h after the removal of the stressor. Ovarian hormones are required for this effect, in that, if the female rats have their ovaries removed prior to the stressor presentation, the startle suppression does not occur.
Ovarian Hormone Regulation of Learning: For over 20 years, researchers and clinicians have tried to understand the role ovarian hormones have in learning and memory processes. In the last 3 years, the debate has ensued since clinical studies failed to show significant maintenance or enhancement of cognitive functioning in post-menopausal women. Our laboratory has been documenting how ovarian hormones (estradiol and progesterone) affect learning by the use of classically conditioning the eyeblink response. The eyeblink response is a simple reflex (initiated by either an electrical or air pressure stimulus) that is preceded by an auditory tone (conditional stimulus) that eventually leads to the development of a conditioned (predictive) eyeblink response when only the auditory stimulus is presented at a later time. This is a very rudimentary form of learning, with well-defined neurocircuitry, that may be more sensitive to subtle effects these hormones have on synaptic plasticity.
- Thus far, our human research component has shown quicker acquisition of the conditioned eyeblink response in women currently using oral contraceptives. As with the startle reactivity measure (described above), this affect appears most robust during the later phases of the menstrual cycle (when the hormone treatments are being ingested - not the placebo pills). However, their may also be a period of slower acquisition proximal to ovulation.
- In rats, we have found that painful stressors cause slower learning of the conditioned eyeblink response. This replicates the work of Tracey Shors lab at Rutgers University. However, unlike the Shors lab, we have found that the rats exposed to stress have reduced responses to the unconditional stimulus. This suggests that stressed rats have lower reflex strength during the repeated pairings. Thus, we still need to determine if stress is affecting the actual plasticity of the association in the cerebellar circuitry or if stress is reducing the amplitude of the signaling representing either the conditional stimulus or the unconditional stimulus.