Patterns of regional recurrence in papillary thyroid cancer patients with lateral neck metastases undergoing neck dissection

Practice variability exists for the extent of neck dissection undertaken for papillary thyroid carcinoma (PTC) metastatic to the lateral neck nodes, with disagreement over routine level V dissection.

from #ORL via a.lsfakia on Inoreader http://ift.tt/2qI009a
via IFTTT

http://ift.tt/2qDy8nn

Transient ischemic attacks on turning the head to one side, with immediate remission of symptoms when the head returned to the neutral position.

http://medicine-greece.blogspot.com/2017/05/transient-ischemic-attacks-on-turning.html

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Characteristic and intermingled neocortical circuits encode different visual object discriminations

Publication date: 28 July 2017
Source:Behavioural Brain Research, Volume 331
Author(s): Guo-rong Zhang, Hua Zhao, Nathan Cook, Michael Svestka, Eui M. Choi, Mary Jan, Robert G. Cook, Alfred I. Geller
Synaptic plasticity and neural network theories hypothesize that the essential information for advanced cognitive tasks is encoded in specific circuits and neurons within distributed neocortical networks. However, these circuits are incompletely characterized, and we do not know if a specific discrimination is encoded in characteristic circuits among multiple animals. Here, we determined the spatial distribution of active neurons for a circuit that encodes some of the essential information for a cognitive task. We genetically activated protein kinase C pathways in several hundred spatially-grouped glutamatergic and GABAergic neurons in rat postrhinal cortex, a multimodal associative area that is part of a distributed circuit that encodes visual object discriminations. We previously established that this intervention enhances accuracy for specific discriminations. Moreover, the genetically-modified, local circuit in POR cortex encodes some of the essential information, and this local circuit is preferentially activated during performance, as shown by activity-dependent gene imaging. Here, we mapped the positions of the active neurons, which revealed that two image sets are encoded in characteristic and different circuits. While characteristic circuits are known to process sensory information, in sensory areas, this is the first demonstration that characteristic circuits encode specific discriminations, in a multimodal associative area. Further, the circuits encoding the two image sets are intermingled, and likely overlapping, enabling efficient encoding. Consistent with reconsolidation theories, intermingled and overlapping encoding could facilitate formation of associations between related discriminations, including visually similar discriminations or discriminations learned at the same time or place.

Graphical abstract

http://ift.tt/2rqL7fC


http://ift.tt/2rraxJO

Transcranial direct current stimulation (tDCS) to improve naming ability in post-stroke aphasia: A critical review

Publication date: 14 August 2017
Source:Behavioural Brain Research, Volume 332
Author(s): Mohammed F. ALHarbi, Susan Armijo-Olivo, Esther S. Kim
PurposeTranscranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulation tool that can be used to influence cortical brain activity to induce measurable behavioral changes. Although there is growing evidence that tDCS combined with behavioural language therapy could boost language recovery in patients with post-stroke aphasia, there is great variability in patient characteristics, treatment protocols, and outcome measures in these studies that poses challenges for analyzing the evidence. The purpose of this study is to critically analyze the methodological rigor of the evidence regarding the use of tDCS for post-stroke anomia.MethodThis critical review was conducted by searching four databases (MEDLINE, EMBase, PsycINFO, and CINAHL). Nineteen studies fully met the inclusion criteria. Three critical appraisal tools and Robey and Schultz's (1998) five- phase model for conducting clinical outcome research were adopted to evaluate and analyze the current level of evidence. Methodological issues of the studies were also identified.ResultsThe current level of evidence for using tDCS for anomia is at the pre-efficacy level with emerging evidence at the efficacy level. Lack of proper evaluation of carry-over effects in cross-over studies, lack of or unclear randomization, allocation concealment, and incomplete data handling were the main methodological issues that could threaten the validity of the tDCS for anomia studies.ConclusionsSeveral methodological issues have been identified in pre-efficacy studies that pose challenges in determining whether tDCS is a beneficial adjunct to behavioral aphasia therapy. Future studies need to improve the quality of the methods used to investigate the effect of tDCS for anomia.



http://ift.tt/2rr65Ls


http://ift.tt/2spl2ut

Effects of exercise on depressive behavior and striatal levels of norepinephrine, serotonin and their metabolites in sleep-deprived mice

Publication date: 14 August 2017
Source:Behavioural Brain Research, Volume 332
Author(s): Thiago Medeiros da Costa Daniele, Pedro Felipe Carvalhedo de Bruin, Emiliano Ricardo Vasconcelos Rios, Veralice Meireles Sales de Bruin
Exercise is a promising adjunctive therapy for depressive behavior, sleep/wake abnormalities, cognition and motor dysfunction. Conversely, sleep deprivation impairs mood, cognition and functional performance. The objective of this study is to evaluate the effects of exercise on anxiety and depressive behavior and striatal levels of norepinephrine (NE), serotonin and its metabolites in mice submitted to 6h of total sleep deprivation (6h-TSD) and 72h of Rapid Eye Movement (REM) sleep deprivation (72h-REMSD). Experimental groups were: (1) mice submitted to 6h-TSD by gentle handling; (2) mice submitted to 72h-REMSD by the flower pot method; (3) exercise (treadmill for 8 weeks); (4) exercise followed by 6h-TSD; (5) exercise followed by 72h-REMSD; (6) control (home cage). Behavioral tests included the Elevated Plus Maze and tail-suspension. NE, serotonin and its metabolites were determined in the striatum using high-performance liquid chromatography (HPLC). Sleep deprivation increased depressive behavior (time of immobilization in the tail-suspension test) and previous exercise hindered it. Sleep deprivation increased striatal NE and previous exercise reduced it. Exercise only was associated with higher levels of serotonin. Furthermore, exercise reduced serotonin turnover associated with sleep deprivation. In brief, previous exercise prevented depressive behavior and reduced striatal high NE levels and serotonin turnover. The present findings confirm the effects of exercise on behavior and neurochemical alterations associated with sleep deprivation. These findings provide new avenues for understanding the mechanisms of exercise.



http://ift.tt/2soVmy3


http://ift.tt/2rraz4o

Opioid receptors mediate the acquisition, but not the expression of mitragynine-induced conditioned place preference in rats

Publication date: 14 August 2017
Source:Behavioural Brain Research, Volume 332
Author(s): Nurul H.M. Yusoff, Sharif M. Mansor, Christian P. Müller, Zurina Hassan
Mitragynine is the main psychoactive ingredient of the herbal drug preparation Kratom (Ketum), derived from the plant Mitragyna speciosa. Kratom is a widely abused drug in Southeast Asian and has a psychostimulant profile at low-medium doses, while high doses have opioidergic effects. Mitragynine was shown to possess opiate receptor affinity. However, its role in the behavioural effects of mitragynine is unclear. Here we asked whether the reinforcing effects of mitragynine are mediated by opiate receptors using a conditioned place preference (CPP) paradigm in rats. In the first experiment we tested the effects of the opiate receptor antagonist naloxone (0.1, 0.3 and 1.0mg/kg) on the acquisition of mitragynine (10mg/kg)-induced CPP. In the second experiment, we tested the involvement of opiate receptors in the expression of mitragynine-induced CPP in rats. We found that naloxone suppresses the acquisition of mitragynine-induced CPP. This effect was already evident at a dose of naloxone (0.1mg/kg) which, by itself, had no conditioned place aversion (CPA) effect. Higher doses of naloxone induced a CPA and blocked mitragynine-induced CPP. In contrast, naloxone had no effect on the expression of mitragynine-induced CPP. These findings suggest that the acquisition, but not the expression of the reinforcing effects of mitragynine is mediated by opiate receptors.



http://ift.tt/2rqYuMG


http://ift.tt/2sp5UNB

Novel reinforcement learning paradigm based on response patterning under interval schedules of reinforcement

Publication date: 28 July 2017
Source:Behavioural Brain Research, Volume 331
Author(s): Christin Schifani, Ilya Sukhanov, Mariia Dorofeikova, Anton Bespalov
There is a need to develop cognitive tasks that address valid neuropsychological constructs implicated in disease mechanisms and can be used in animals and humans to guide novel drug discovery. Present experiments aimed to characterize a novel reinforcement learning task based on a classical operant behavioral phenomenon observed in multiple species – differences in response patterning under variable (VI) vs fixed interval (FI) schedules of reinforcement. Wistar rats were trained to press a lever for food under VI30s and later weekly test sessions were introduced with reinforcement schedule switched to FI30s. During the FI30s test session, post-reinforcement pauses (PRPs) gradually grew towards the end of the session reaching 22–43% of the initial values. Animals could be retrained under VI30s conditions, and FI30s test sessions were repeated over a period of several months without appreciable signs of a practice effect. Administration of the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 ((5S,10R)-(+)-5-Methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate) prior to FI30s sessions prevented adjustment of PRPs associated with the change from VI to FI schedule. This effect was most pronounced at the highest tested dose of MK-801 and appeared to be independent of the effects of this dose on response rates. These results provide initial evidence for the possibility to use different response patterning under VI and FI schedules with equivalent reinforcement density for studying effects of drug treatment on reinforcement learning.



http://ift.tt/2spdPKU


http://ift.tt/2rqTqba