“The ventral striatum seems to play an important role during working memory (WM) tasks when irrelevant information needs to be filtered out. However, the concrete neural mechanisms underlying this process are still unknown. In this study, we investigated these mechanisms Selleck JQ1 in detail. Eighteen healthy human participants were presented with multiple items consisting of faces or buildings. They either had to maintain two or four
items from one category (low- and high-memory-load condition), or two from one category and suppress (filter out) two items from the other category (distraction condition). Striatal activity was increased in the distraction as compared with the high-load condition. Activity in category-specific regions in the inferior temporal cortex [fusiform face area (FFA) and parahippocampal place area (PPA)] was reduced when items from the other category PLX4032 ic50 needed to be selectively maintained. Furthermore, functional connectivity analysis showed significant reduction of striatal–PPA correlations during selective maintenance of faces. However, striatal–FFA connectivity was not reduced during maintenance of buildings vs. faces, possibly because face stimuli are more salient. Taken together, our results suggest that the ventral striatum supports selective WM maintenance by reduced gating of task-irrelevant activity via attenuating functional connectivity without increasing task-relevant activity correspondingly.
“Transcranial magnetic stimulation (TMS) over the occipital pole can produce an illusory percept of a light flash (or ‘phosphene’), suggesting an excitatory effect. Whereas previous reported effects produced by single-pulse occipital pole TMS are typically disruptive, here we report the first demonstration of a location-specific facilitatory effect on visual perception in humans. Observers performed a spatial cueing orientation discrimination task. An
orientation target was presented in one of two peripheral placeholders. A single pulse below the phosphene threshold applied to the occipital pole 150 or 200 ms before stimulus onset was found to facilitate target Progesterone discrimination in the contralateral compared with the ipsilateral visual field. At the 150-ms time window contralateral TMS also amplified cueing effects, increasing both facilitation effects for valid cues and interference effects for invalid cues. These results are the first to show location-specific enhanced visual perception with single-pulse occipital pole stimulation prior to stimulus presentation, suggesting that occipital stimulation can enhance the excitability of visual cortex to subsequent perception. “
“Corticosterone (CORT) is a glucocorticoid produced by adrenal glands under the control of the hypothalamic–pituitary–adrenal axis. Circulating CORT can enter the central nervous system and be reduced to neuroactive 3α5α-reduced steroids, which modulate GABAA receptors.