Visuo-Acoustic Stimulation's Role in Synaptic Plasticity: A Review of the Literature.

Brain plasticity is the capacity of cerebral neurons to change, structurally and functionally, in response to experiences. This is an essential property underlying the maturation of sensory functions, learning and memory processes, and brain repair in response to the occurrence of diseases and trauma. In this field, the visual system emerges as a paradigmatic research model, both for basic research studies and for translational investigations. The auditory system remains capable of reorganizing itself in response to different auditory stimulations or sensory organ modification. Acoustic biofeedback training can be an effective way to train patients with the central scotoma, who have poor fixation stability and poor visual acuity, in order to bring fixation on an eccentrical and healthy area of the retina: a pseudofovea. This review article is focused on the cellular and molecular mechanisms underlying retinal sensitivity changes and visual and auditory system plasticity.

Primary signet ring cell carcinoma of the pancreas A case report about an extremely rare variant of pancreatic carcinoma.

INTRODUCTION: Primary signet ring cell carcinoma of the pancreas (PSRCCP) is an extremely rare histologic variant of pancreatic carcinoma, which cells are characterized by large mucin vacuoles and peripheric nucleus that producing a signet ring aspect. CASE REPORT: We present a case about 66 years old man, with history of chronic pancreatitis and Wirsung stenosis of unknown origin, came to our attention for abdominal pain compatible with pancreatitis exacerbation. A TC scan showed a head of pancreas' neoformation, and a MRI showed numerous metastatic liver lesions confirming the presence of pancreatic lesion (52x46) mm. Fine needle aspiration biopsy of liver was suggestive of signet ring cell carcinoma. As second step, an ERCP was performed in order to get a biopsy of pancreatic lesion and drain the biliary tract. No surgical approach was possible as well as the progressive complications arised after diagnosis contraindicated chemotherapy. The patient died 3 month after diagnosis. CONCLUSION: PSRCCP is an aggressive malignancy with low survival rate, because of high metastatization rate. Only 9 cases are described in literature at December 2019, so we consider our work a precious contribute to knowledge. KEY WORDS: Pancreatic tumor, Pancreas, Pancreatic carcinoma, Primary signet ring cell carcinoma of the pancreas. Signet ring cell carcinoma.