The eyeblink component of the acoustic startle reflex was assessed using electromyographic measurements of m. orbicularis oculi. Twenty pulse-alone trials ( 115 dB 40 ms broad-band white noise) and 40 prepulse-pulse trials were presented. The prepulse stimuli consisted
of a 115 dB 40 ms noise burst preceded at a 100 ms interval by 20 ms prepulses that were 72, 74, 78, or 86 dB. PMDD patients had a significantly higher startle response than controls during both phases of the menstrual cycle (p<0.05). PMDD patients exhibited lower levels of prepulse inhibition with 78 dB and 86 dB prepulses compared to control subjects in the luteal (p<0.01) but not in the follicular phase. Whereas control subjects displayed increased PPI during the late luteal phase compared to the follicular phase (p<0.01), PPI magnitude remained unchanged in PMDD NU7026 patients between cycle phases. Relative to
controls, PMDD patients displayed increased startle reactivity across both menstrual cycle phases and deficits in prepulse inhibition of acoustic startle during the late luteal phase. LEE011 concentration These findings are consistent with an altered response to ovarian steroids among PMDD patients.”
“Central serotonin (5-HT) has been implicated in emotional and behavioral control processes for many decades, but its precise contribution is not well understood. We used the acute tryptophan depletion procedure in young healthy volunteers to test the hypothesis that central 5-HT is critical for predicting punishment. An observational reversal-learning task was employed that provided separate measures of punishment and reward prediction. Under baseline, subjects made more prediction errors for punishment-associated stimuli than for reward-associated stimuli. This bias was abolished after central click here 5-HT depletion, which enhanced the ability to predict punishment while not affecting reward prediction. The selective potentiation of punishment
prediction concurs with recent theorizing, suggesting that central 5-HT carries a prediction error for future punishment, but not for future reward (Daw et al, 2002). Furthermore, the finding highlights the importance of central 5-HT in resilience to adversity and may have implications for a variety of neuropsychiatric disorders including depression and anxiety.”
“Systematic reviews of systematic reviews identify good quality reviews of earlier studies of medical conditions. This article describes a systematic review of systematic reviews performed to investigate factors that might influence the risk of rupture of an intracranial aneurysm. It exemplifies the technique of this type of research and reports the finding of a specific study. The annual incidence of subarachnoid haemorrhage resulting from the rupture of intracranial aneurysms is estimated to be nine per 100,000.