A study, carried out by researchers at University of California – Los Angeles ( UCLA ), showed that changes in certain brain receptors can affect seizures and anxiety during the menstrual cycle.
These findings could lead to novel therapies for premenstrual dysphoric disorder ( PMDD, formerly known as PMS ) and other central nervous system symptoms associated with the menstrual cycle.

The study, " Ovarian Cycle-Linked Changes in GABAA Receptors Mediating Tonic Inhibition Alter Seizure Susceptibility and Anxiety, " has been published in Nature Neuroscience.

The findings also may be applicable to post-partum depression and mood swings during pregnancy, and may explain how stress hormones affect the brain, said Istvan Mody, at the Reed Neurological Research Center at the David Geffen School of Medicine at UCLA.

" This may provide novel therapeutic targets for curing PMDD ( PMS ) or catamenial epilepsy, a form of epilepsy in women that is exacerbated during certain stages of the menstrual cycle, or other mental or neurological disorders related to changes in steroid hormone levels, " said Mody, the study's lead researcher. " If some of our findings are replicated in humans, our study would provide some testable predictions about new therapies. "

Basing their findings on a study of the estrous cycle in mice - the equivalent of the human menstrual cycle - the researchers found that a specific subclass of the receptors called GABAA receptors change in the hippocampus during the cycle.
These changes take place in a part of the brain where progesterone-derived neurosteroids are active, and are inexorably linked to an altered behavior of nerve cells, which in turn changes the whole animal's susceptibility to seizures and anxiety.

" This may be quite relevant to the way nerve cells respond to stimuli in the human brain during the menstrual cycle, " Mody said.

The changes may spark seizures in women with catamenial epilepsy and may lead to the increased anxiety women experience during PMDD.

The next step will be to determine the precise mechanisms behind these changes.

Source: University of California - Los Angeles ( UCLA ), 2005


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