Variation in early life maternal care predicts later long range frontal cortex synapse development in mice.

Empirical and theoretical work suggests that early postnatal experience may inform later developing synaptic connectivity to adapt the brain to its environment. We hypothesized that early maternal experience may program the development of synaptic density on long range frontal cortex projections. To test this idea, we used maternal separation (MS) to generate environmental variability and examined how MS affected 1) maternal care and 2) synapse density on virally-labeled long range axons of offspring reared in MS or control conditions. We found that MS and variation in maternal care predicted bouton density on dorsal frontal cortex axons that terminated in the basolateral amygdala (BLA) and dorsomedial striatum (DMS) with more, fragmented care associated with higher density. The effects of maternal care on these distinct axonal projections of the frontal cortex were manifest at different ages. Maternal care measures were correlated with frontal cortex → BLA bouton density at mid-adolescence postnatal (P) day 35 and frontal cortex → DMS bouton density in adulthood (P85). Meanwhile, we found no evidence that MS or maternal care affected bouton density on ascending orbitofrontal cortex (OFC) or BLA axons that terminated in the dorsal frontal cortices. Our data show that variation in early experience can alter development in a circuit-specific and age-dependent manner that may be relevant to understanding the effects of early life adversity

Early maternal separation impacts cognitive flexibility at the age of first independence in mice.

Early life adversity is associated with increased risk for mental and physical health problems, including substance abuse. Changes in neural development caused by early life insults could cause or complicate these conditions. Maternal separation (MS) is a model of early adversity for rodents. Clear effects of MS have been shown on behavioral flexibility in rats, but studies of effects of MS on cognition in mice have been mixed. We hypothesized that previous studies focused on adult mice may have overlooked a developmental transition point when juvenile mice exhibit greater flexibility in reversal learning. Here, using a 4-choice reversal learning task we find that early MS leads to decreased flexibility in post-weaning juvenile mice, but no significant effects in adults. In a further study of voluntary ethanol consumption, we found that adult mice that had experienced MS showed greater cumulative 20% ethanol consumption in an intermittent access paradigm compared to controls. Our data confirm that the MS paradigm can reduce cognitive flexibility in mice and may enhance risk for substance abuse. We discuss possible interpretations of these data as stress-related impairment or adaptive earlier maturation in response to an adverse environment

Long-range orbitofrontal and amygdala axons show divergent patterns of maturation in the frontal cortex across adolescence.

The adolescent transition from juvenile to adult is marked by anatomical and functional remodeling of brain networks. Currently, the cellular and synaptic level changes underlying the adolescent transition are only coarsely understood. Here, we use two-photon imaging to make time-lapse observations of long-range axons that innervate the frontal cortex in the living brain. We labeled cells in the orbitofrontal cortex (OFC) and basolateral amygdala (BLA) and imaged their axonal afferents to the dorsomedial prefrontal cortex (dmPFC). We also imaged the apical dendrites of dmPFC pyramidal neurons. Images were taken daily in separate cohorts of juvenile (P24-P28) and young adult mice (P64-P68), ages where we have previously discovered differences in dmPFC dependent decision-making. Dendritic spines were pruned across this peri-adolescent period, while BLA and OFC afferents followed alternate developmental trajectories. OFC boutons showed no decrease in density, but did show a decrease in daily bouton gain and loss with age. BLA axons showed an increase in both bouton density and daily bouton gain at the later age, suggesting a delayed window of enhanced plasticity. Our findings reveal projection specific maturation of synaptic structures within a single frontal region and suggest that stabilization is a more general characteristic of maturation than pruning

Leadership and the Liberal Arts: Achieving the Promise of a Liberal Education

A collection of essays by presidents of prominent liberal arts colleges and leading intellectuals who reflect on the meaning of educating individuals for leadership and how it can be accomplished in ways consistent with the missions of liberal arts institutions. Edited by faculty from the Jepson School for Leadership Studies at the University of Richmond, the Jepson Studies in Leadership series will reflect the school\u27s broad-based, liberal arts approach to the study of leadership. The Jepson School has faculty representatives from the disciplines of English literature, history, philosophy, political science, psychology, public administration, religious studies, and organizational leadership. No other school or program is better situated to provide a multidisciplinary perspective on this important topic.https://scholarship.richmond.edu/bookshelf/1020/thumbnail.jp

Leadership and the Liberal Arts: Achieving the Promise of a Liberal Education

A collection of essays by presidents of prominent liberal arts colleges and leading intellectuals who reflect on the meaning of educating individuals for leadership and how it can be accomplished in ways consistent with the missions of liberal arts institutions. Edited by faculty from the Jepson School for Leadership Studies at the University of Richmond, the Jepson Studies in Leadership series will reflect the school\u27s broad-based, liberal arts approach to the study of leadership. The Jepson School has faculty representatives from the disciplines of English literature, history, philosophy, political science, psychology, public administration, religious studies, and organizational leadership. No other school or program is better situated to provide a multidisciplinary perspective on this important topic.https://scholarship.richmond.edu/bookshelf/1020/thumbnail.jp

The International Library of Leadership

The International Library of Leadership brings together in one place the most significant writings on leadership, the process by which groups, organizations, and societies seek to satisfy their needs and achieve their objectives. Volume 1 focuses on classic discussions of perennial leadership issues including the moral purpose of leadership, the nature of legitimate authority, and the role of followers. Volume 2 turns to investigations of leadership in the modern era and makes available the seminal social scientific works that inaugurated the modern theories of leadership. Volume 3 builds upon the analyses of power, culture, and gender in the first two volumes to address current ethical, democratic, and international challenges of leadership.https://scholarship.richmond.edu/bookshelf/1002/thumbnail.jp

Imaging striatal dopamine release using a nongenetically encoded near infrared fluorescent catecholamine nanosensor.

Neuromodulation plays a critical role in brain function in both health and disease, and new tools that capture neuromodulation with high spatial and temporal resolution are needed. Here, we introduce a synthetic catecholamine nanosensor with fluorescent emission in the near infrared range (1000-1300 nm), near infrared catecholamine nanosensor (nIRCat). We demonstrate that nIRCats can be used to measure electrically and optogenetically evoked dopamine release in brain tissue, revealing hotspots with a median size of 2 µm. We also demonstrated that nIRCats are compatible with dopamine pharmacology and show D2 autoreceptor modulation of evoked dopamine release, which varied as a function of initial release magnitude at different hotspots. Together, our data demonstrate that nIRCats and other nanosensors of this class can serve as versatile synthetic optical tools to monitor neuromodulatory neurotransmitter release with high spatial resolution

Haptic Guidance and Haptic Error Amplification in a Virtual Surgical Robotic Training Environment

Teleoperated robotic systems have introduced more intuitive control for minimally invasive surgery, but the optimal method for training remains unknown. Recent motor learning studies have demonstrated that exaggeration of errors helps trainees learn to perform tasks with greater speed and accuracy. We hypothesized that training in a force field that pushes the operator away from a desired path would improve their performance on a virtual reality ring-on-wire task. Forty surgical novices trained under a no-force, guidance, or error-amplifying force field over five days. Completion time, translational and rotational path error, and combined error-time were evaluated under no force field on the final day. The groups significantly differed in combined error-time, with the guidance group performing the worst. Error-amplifying field participants showed the most improvement and did not plateau in their performance during training, suggesting that learning was still ongoing. Guidance field participants had the worst performance on the final day, confirming the guidance hypothesis. Participants with high initial path error benefited more from guidance. Participants with high initial combined error-time benefited more from guidance and error-amplifying force field training. Our results suggest that error-amplifying and error-reducing haptic training for robot-assisted telesurgery benefits trainees of different abilities differently.Comment: 11 pages, 7 Figure, Under Revie