Response inhibition, the ability to refrain from unwanted actions, is an essential component of complex behavior and is often impaired across numerous neuropsychiatric disorders such as addiction, attention-deficit hyperactivity disorder (ADHD), schizophrenia, and obsessive-compulsive disorder. Accordingly, much research has been devoted to characterizing brain regions responsible for the regulation of response inhibition. The stop-signal task, a task in which animals are required to inhibit a prepotent response in the presence of a STOP cue, is one of the most well-studied tasks of response inhibition. While pharmacological evidence suggests that dopamine (DA) contributes to the regulation of response inhibition, what is exactly encoded by DA neurons during performance of response inhibition tasks is unknown. To address this issue, we recorded from single units in the ventral tegmental area (VTA), while rats performed a stop-change task. We found that putative DA neurons fired less and higher to cues and reward on STOP trials relative to GO trials, respectively, and that firing was reduced during errors. These results suggest that DA neurons in VTA encode the uncertainty associated with the probability of obtaining reward on difficult trials instead of the saliency associated with STOP cues or the need to resolve conflict between competing responses during response inhibition.

Background: The AeroForm tissue expander is a carbon dioxide-filled breast tissue expander that allows gradual, needle-free expansion using a hand-held remote controller. This study evaluates 2-stage, prepectoral tissue expander-to-implant breast reconstruction with the carbon-dioxide tissue expanders and compares the outcomes to our recent experience with saline tissue expanders. Methods: This was a retrospective study of consecutive patients from a single institution. The subjects consisted of women who underwent mastectomy and either immediate or delayed breast reconstruction with AeroForm or saline tissue expanders. Outcomes encompassed postoperative complications including mastectomy flap necrosis, infection requiring readmission and/or intravenous antibiotics, capsular contracture, hematoma, seroma, skin dehiscence, extrusion, premature explant, and loss of communication with the device (AeroForm) or rupture of the device (saline). Results: This study evaluated 115 patients with 185 breast reconstructions. Of the 185 breast reconstructions, 74 (40%) utilized AeroForm tissue expanders and 111 (60%) utilized traditional saline tissue expanders. Treatment was successful in 100% and 94% in the AeroForm and saline groups, respectively ( P = 0.025). The incidence of adverse events was greater in the saline group (45.9% versus 32.4%). Surgical-site infection occurred more commonly in the saline group (5.4% versus 0%). Full-thickness skin necrosis occurred at a significantly higher rate in the saline cohort as compared with AeroForm (5.4% versus 0%). Conclusions: The use of AeroForm tissue expanders offers notable advantages for breast reconstruction. This device when employed in the prepectoral space may be associated with reduced infection rates and decreased utilization of healthcare and patient resources.

The ability to adjust behavior is an essential component of cognitive control. Much is known about frontal and striatal processes that support cognitive control, but few studies have investigated how motor signals change during reactive and proactive adjustments in motor output. To address this, we characterized neural signals in red nucleus (RN), a brain region linked to motor control, as male and female rats performed a novel variant of the stop-signal task. We found that activity in RN represented the direction of movement and was strongly correlated with movement speed. Additionally, we found that directional movement signals were amplified on STOP trials before completion of the response and that the strength of RN signals was modulated when rats exhibited cognitive control. These results provide the first evidence that neural signals in RN integrate cognitive control signals to reshape motor outcomes reactively within trials and proactivity across them.

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