Norepinephrine, beyond the Synapse: Coordinating Epigenetic Codes for Memory.

The noradrenergic system is implicated in neuropathologies contributing to major disorders of the memory, including post-traumatic stress disorder and Alzheimer's disease. Determining the impact of norepinephrine on cellular function and plasticity is thus essential for making inroads into our understanding of these brain conditions, while expanding our capacity for treating them. Norepinephrine is a neuromodulator within the mammalian central nervous system which plays important roles in cognition and associated synaptic plasticity. Specifically, norepinephrine regulates the formation of memory through the stimulation of ß-ARs, increasing the dynamic range of synaptic modifiability. The mechanisms through which NE influences neural circuit function have been extended to the level of the epigenome. This review focuses on recent insights into how the noradrenergic recruitment of epigenetic modifications, including DNA methylation and post-translational modification of histones, contribute to homo- and heterosynaptic plasticity. These advances will be placed in the context of synaptic changes associated with memory formation and linked to brain disorders and neurotherapeutic applications.

Innervated Pedicled Gracilis Flap for Dynamic Abdominal Wall Reconstruction.

Abdominal wall reconstruction for full-thickness defects is a challenging procedure that usually requires the use of flaps. The gracilis flap is known to be used in hernia repair in which the abdominal muscles are still intact, but there are no reports in literature describing the use of an innervated gracilis for dynamic abdominal wall reconstruction after tissue loss due to severe trauma. We present a surgical technique in which the gracilis is harvested preserving the neurovascular pedicle, then tunneled underneath the adductor longus to cover the lower abdominal defect and provide it with basal muscle tone without tension on the pedicle. This results in restored integrity of the musculofascial abdominal wall and dynamic muscle function and support. The gracilis flap has been proven to be useful and versatile in reconstructive surgery with great potential in abdominal wall reconstruction having minimal donor-site morbidity and hernia recurrence risk.