Thalamo-hippocampal pathway regulates incidental memory capacity in mice

Incidental memory can be challenged by increasing either the retention delay or the memory load. The dorsal hippocampus (dHP) appears to help with both consolidation from short-term (STM) to long-term memory (LTM), and higher memory loads, but the mechanism is not fully understood. Here we find that female mice, despite having the same STM capacity of 6 objects and higher resistance to distraction in our different object recognition task (DOT), when tested over 1 h or 24 h delays appear to transfer to LTM only 4 objects, whereas male mice have an STM capacity of 6 objects in this task. In male mice the dHP shows greater activation (as measured by c-Fos expression), whereas female mice show greater activation of the ventral midline thalamus (VMT). Optogenetic inhibition of the VMT-dHP pathway during off-line memory consolidation enables 6-object LTM retention in females, while chemogenetic VMT-activation impairs it in males. Thus, removing or enhancing sub-cortical inhibitory control over the hippocampus leads to differences in incidental memory.

Incidental memory is affected by retention delay, and by memory load. Here the authors show that female and male mice process high memory load through different activation of thalamic-cortical pathways, that makes their incidental memory resistant to distraction and to memory decay, respectively.

Circulating miRNAs expression as potential biomarkers of mild traumatic brain injury

TBI is the main cause of death and disability in individuals aged 1-45 in Western countries. One of the main challenges of TBI at present is the lack of specific diagnostic biomarkers, especially for mild TBI (mTBI), which remains currently difficult to value in clinical practice. In this context MiRNAs may be important mediators of the profound molecular and cellular changes that occur after TBI in both the short and the long term. Recently, plasma miRNAs profiling in human TBI, have revealed dynamic temporal regulation of miRNA expression within the cortex. Aim of this study was to select a specific miRNAs panel for mTBI, by focusing the research on the prognostic meaning of miRNAs in the hours following the trauma, in order to be able to use this MIRNAs as potential biomarkers useful for monitoring the follow up of mild TBI. Serum levels of 17 miRNAs were measured by RT-quantitative polymerase chain reaction (qPCR) in 20 patients with mTBI at three different time-points (0 h, 24 h, 48 h) and in 10 controls. For 15 miRNAs we found a significant differences in the comparison among the three time points: for each of these miRNAs the values were greater at baseline and progressively reduced at 24 h and 48 h. These data allow us to consider the miRNAs included in panel as sensitive and specific biomarkers for mTBI, useful in monitoring the post-trauma period.

[Treatment of obstructive defecation syndrome related to hedrocele. Our experience]

Hedrocele represents an unusual variant of the rare posterior perineal hernia and results from a defect in the rectogenital septum. We report two cases of obstructive defecation syndrome (ODS) related to presence of hedrocele successfully treated by laparoscopy-assisted transanal surgery.

Effect of bombesin on glucose-induced insulin release in humans

The effect of bombesin on basal and glucose-stimulated insulin release was studied in male healthy volunteers. Glucose was administered by oral, intravenous or intraduodenal route during saline or bombesin infusion (5 ng/kg/min for 60 min). The peptide had no significant effect on basal levels of glucose and insulin. However, during its administration, the insulin response and the expected rise in blood glucose after oral glucose load (50 g) were strongly inhibited, and the gastric emptying of liquids was significantly delayed. On the contrary, the insulin response to intravenous glucose (20 g) was significantly increased by bombesin without changes in plasma glucose levels. Finally, when glucose was infused into the duodenum, thus bypassing the stomach, the insulin response was significantly increased by the peptide. In this case, too, plasma glucose levels after glucose load were virtually identical during either bombesin or saline infusion. These data clearly demonstrate that the direct effect of bombesin on insulin release is stimulatory and suggest that the inhibitory effect observed after oral glucose is connected with the action of the peptide on gastric emptying, the delay of which slows the entry of glucose into the small bowel.

[Contrast radiographic study of ductal pathology of the breast]

On the basis of personal experience, the possibility and the limits of galactography are discussed. Galactography has been used by the authors in any cases of discharge from the nipple, and has shown to be the only radiological examination able to discover intraductal tumours. Furthermore it allows to establish the site and extension of the lesions. Among the limits of the method the impossibility to distinguish between benign and malignant lesions is stressed out.

[Autograft of pancreatic tissue in the spleen of pancreatectomized dogs]

The intrasplenic autotransplant of pancreatic fragments in dogs subjected to total pancreatectomy can prevent diabetes as it maintains normoglycaemic condition and a normal insulinaemic response to i.v. infusion of glucose. By adopting a pancreatic tissue preparation technique which provides for a very short collagenasis digestion time (4 minutes), B cells took and normal glucidic metabolism was maintained.

[Effects of surgery and anesthesia on serum immunoglobulins]

Serum immunoglobulins levels after surgery with and without anaesthesia are reported. No significant change was found after surgery without anaesthesia; significant changes of serum Ig (A,G,M) were observed in surgery with anaesthesia (60-180 m') group on day 1 following operation. This Ig decrease is probably due to a reduced immunologic response by long anaesthesia.