Early stage of adjuvant arthritis alters behavioral responses in male but not female rats.

Anxiety and depression commonly occur in the pathology of rheumatic diseases. Little is known about how inflammatory disease in its early stage, before any clinical manifestation, may affect general activity. The aim of this study was to compare the anxiety-like behaviour in the early stage of adjuvant arthritis (AA), and the paw edema, and corticosterone (CORT) levels in the developed stage of AA among male and female Long Evans rats. The behavioural activity was evaluated by elevated plus maze tests. These revealed significantly reduced number of entries into the open arm of the maze in arthritic males compared to controls or to females 4 days after AA induction. Arthrihtic and control females did not differ. The number of entries into the closed arm of the maze was the same across the genders and studied intervals. Time spent in the open arm was significantly lower in arthritic males against controls or arthitic females. Time spent in the closed arm showed inverse picture to the time spent in the open arm. Hind paw swelling measured on day 23 of AA was the same in males and females, as was the elevation of CORT levels in plasma. Male rats showed anxiety-like behaviour on day 4 of AA, while female rats did not show any change, indicating different brain sensitivity to early inflammation among the genders.

Proton magnetic resonance spectroscopy measurement of brain glutamate levels in premenstrual dysphoric disorder.

BACKGROUND: Women who suffer from premenstrual dysphoric disorder (PMDD) classically display depressive and anxiety symptoms in the premenstrum. Preclinical and clinical studies have suggested a role of glutamate in anxiety and depression. This investigation aims at demonstrating fluctuations of glutamate across the menstrual cycle in the medial prefrontal cortex of women who suffer from PMDD and healthy control subjects (HCs). METHODS: Twelve PMDD women and 13 HCs were randomized to two single-voxel 3 Tesla proton magnetic resonance spectroscopy examinations of the medial prefrontal cortex during the follicular phase and the luteal phase. RESULTS: A phase effect was observed; the levels of glutamate/creatine plus phosphocreatine (Cr) were significantly lower during the luteal phase compared with the follicular phase. However, no statistically significant diagnosis or phase x diagnosis effects were found. CONCLUSIONS: The optimized stimulated echo acquisition mode (STEAM) pulse timings selected in this study (echo time [TE], mixing time [TM] = 240, 27 msec) allow us to interpret our results as the first report of alterations of brain glutamate levels across the menstrual cycle. Hormonal fluctuations associated with the menstrual cycle likely contribute to these glutamate level variations. Although PMDD women undergo a similar decrease in glutamate during the luteal phase as the HCs, PMDD women may display an increased behavioral sensitivity to those phase-related alterations. These menstrual cycle-related variations of glutamate levels may also contribute to the influence of the phases of the menstrual cycle in other neuropsychiatric disorders.