Primary sensory cortices display functional topography, suggesting that even small cortical volumes may underpin perception of specific stimuli. Traditional loss-of-function approaches have a relatively large radius of effect (>1 mm), and few studies track recovery following loss-of-function perturbations. Consequently, the behavioral necessity of smaller cortical volumes remains unclear. In the mouse primary vibrissal somatosensory cortex (vS1), “barrels” with a radius of ∼150 μm receive input predominantly from a single whisker, partitioning vS1 into a topographic map of well defined columns. Here, we train animals implanted with a cranial window over vS1 to perform single-whisker perceptual tasks. We then use high-power laser exposure centered on the barrel representing the spared whisker to produce lesions with a typical volume of one to two barrels. These columnar-scale lesions impair performance in an object location discrimination task for multiple days without disrupting vibrissal kinematics. Animals with degraded location discrimination performance can immediately perform a whisker touch detection task with high accuracy. Animals trained de novo on both simple and complex whisker touch detection tasks showed no permanent behavioral deficits following columnar-scale lesions. Thus, columnar-scale lesions permanently degrade performance in object location discrimination tasks.

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Introduction Irritability has been proposed to be a core symptom of male-specific major depressive disorder (MDD), with a greater propensity to experiencing anger attacks and overreacting to minor annoyances compared to females with MDD. Males with MDD have also been shown to exhibit a pattern of reduced slow-wave sleep (SWS) that is not characteristic of females. Because SWS has been implicated in the homeostatic regulation of neuroplasticity, it is possible that this mood dysfunction in males is a result of SWS alterations via impairments in neuroplasticity. Therefore, in this study we aimed to manipulate SWS and examine its impact on mood. Methods 19 individuals (11 F) with MDD were recruited for an ongoing clinical trial. Participants spent two nights in the sleep laboratory one week apart: a baseline (BL) night, and a night of slow-wave sleep disruption (SWD) utilizing auditory stimulation. Irritability was assessed in the morning following each overnight visit using the 5-item Brief Irritability Test (BITe). Repeated measures ANOVA was used to evaluate the change in irritability following SWD with condition (BL, SWD) as the within-subject factor and sex (M, F) as the between-subjects factor. Results Results revealed a significant Condition x Sex interaction (F(1,17) =10.1, p=.006) for change in irritability scores, with post-hoc t-tests indicating that males with MDD showed a significant decrease in irritability following SWD, t(7)=2.22, p<.05 while women showed a significant increase in irritability, t(10)=-2.34, p<.05. Changes in irritability were not found to be associated with changes in N3. Conclusion These data demonstrate that experimentally reducing SWS decreases irritability, a core symptom of mood dysfunction, in males with MDD. As SWS has been theorized to facilitate synaptic downscaling, these results may indicate that maintaining waking levels of synaptic strength in males improves depressive symptomatology and may point to the importance of sex differences in sleep and psychopathology. Moreover, these results suggest that the modulation of neuroplasticity via sleep manipulation may be a potential therapeutic target. Support (If Any) K23MH118580 (JG)

Introduction Evidence suggests that individuals with generalized anxiety disorder exhibit decreases in slow-wave sleep (SWS). Because SWS has been shown to be modifiable, it is imperative to better understand the relationship between symptoms of anxiety and amount of SWS to inform treatment development. This study aimed to explore the relationship between anxiety and SWS, and to investigate the impact of slow-wave sleep disruption on state anxiety. Methods Twenty-seven participants’ (mean age 30.9) were recruited as part of an ongoing study examining the relationship between SWS and depression. Participants spent two nights in the laboratory: baseline (BL) and slow-wave disruption (SWD), where SWS was disrupted using auditory stimulation. Anxiety was measured using the State-Trait Anxiety Inventory (STAI). Both trait and state anxiety (BL, SWD) measures were collected. Repeated measures ANOVA was used to determine the impact of SWD on state anxiety. Results Participants’ trait anxiety scores were significantly correlated with percent N3, such that greater anxiety was associated with less N3 (r = -0.43; p<0.05). Individuals were then categorized as either high-anxiety (HA) or low-anxiety (LA) by median split (M=46.5). Results of the repeated measures showed a significant main effect of group (F=43.963; p<0.001), with HA individuals showing greater state anxiety than LA individuals. A significant interaction of group*condition was also found (F(1,24)=4.703; p=0.40). LA participants showed a significant increase in state anxiety following SWD (t=-2.539; p=0.028), while HA participants showed no change. Conclusion The current findings replicate previous research showing that anxious individuals have a reduced amount of SWS and demonstrate that decreases in SWS may exacerbate anxiety in individuals with low anxiety. Further, this work suggests that individuals with high anxiety may be more resilient to changes in anxiety state than individuals with low anxiety when SWS is reduced. Support (If Any) Goldschmied: K23MH118580 (NIMH)

Introduction Research has demonstrated that sleep deprivation may alter emotion recognition. Given that emotion recognition is critical for effective human communication, it is essential to understand how sleep is involved in this process. Slow-wave sleep (SWS) has been suggested to be important for the consolidation and processing of emotional memories and neuroplasticity. This study aimed to examine the impact of experimental disruption of SWS on emotion recognition to further understand the contribution of SWS. Methods 31 participants (20 individuals diagnosed with Major Depressive Disorder (MDD), 11 healthy controls (HC)) completed two overnight sleep studies spaced one week apart. One night served as baseline (BL) and on the other night participants underwent slow-wave disruption (SWD), where SWS was disrupted using auditory stimulation. In the morning following each overnight visit, participants completed an emotion recognition task. Accuracy scores were computed as the percentage correct in each of 10 categories of emotions (anger, contempt, disgust, embarrassment, fear, joy, neutral, pride, sadness, and surprise). Repeated measures ANOVA was used to assess the impact of SWD on emotion recognition with group (HC, MDD) as the between subjects factor and condition (BL, SWD) as the within subjects factor. Results Results revealed a significant main effect of condition for disgust (F=13.72, p< .001), embarrassment (F=6.23, p=.019), and surprise (F=8.06, p=.008), with follow-up t-tests demonstrating that accuracy for the recognition of disgust and embarrassment decreased following SWD and accuracy for surprise increasing following SWD. No significant interactions were found for group*condition (ps>.105). Conclusion These results suggest that while SWD decreases the ability to recognize certain negative emotions, it also increases the ability to recognize surprise, which is in line with previous research examining acute total sleep deprivation. Interestingly, there appears to be no difference in the ability to recognize emotions between individuals with and without depression. Slow-wave sleep deficits, common in disorders such as depression and schizophrenia, may therefore contribute to poor communication abilities through decreased ability to recognize emotions, increasing the risk of interpersonal distress and mental health problems. Support (If Any) Goldschmied: K23MH118580 (NIMH)