Flavoprotein fluorescence imaging-based electrode implantation for subfield-targeted chronic recording in the mouse auditory cortex

Publication date: Available online 26 August 2017
Source:Journal of Neuroscience Methods
Author(s): Jun Nishikawa, Yuto Ohtaka, Yuishi Tachibana, Yasutaka Yanagawa, Hisayuki Osanai, Takeaki Haga, Takashi Tateno
BackgroundChronic neural recording in freely moving animals is important for understanding neural activities of cortical neurons associated with various behavioral contexts. In small animals such as mice, it has been difficult to implant recording electrodes into exact locations according to stereotactic coordinates, skull geometry, or the shape of blood vessels. The main reason for this difficulty is large individual differences in the exact location of the targeted brain area.New methodsWe propose a new electrode implantation procedure that is combined with transcranial flavoprotein fluorescence imaging. We demonstrate the effectiveness of this method in the auditory cortex (AC) of mice.Results: Prior to electrode implantation, we executed transcranial flavoprotein fluorescence imaging in anesthetized mice and identified the exact location of AC subfields through the skull in each animal. Next, we surgically implanted a microdrive with a tungsten electrode into exactly the identified location. Finally, we recorded neural activity in freely moving conditions and evaluated the success rate of recording auditory responses.Comparison with existing method(s)These procedures dramatically improved the success rate of recording auditory responses from 21.1% without imaging to 100.0% with imaging. We also identified large individual differences in positional relationships between sound-driven response areas and the squamosal suture or blood vessels.ConclusionsCombining chronic electrophysiology with transcranial flavoprotein fluorescence imaging before implantation enables the realization of reliable subfield-targeted neural recording from freely moving small animals.



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State of knowledge of research in the Guinean forests of West Africa region

Publication date: Available online 26 August 2017
Source:Acta Oecologica
Author(s): Luca Luiselli, Daniele Dendi, Edem A. Eniang, Barineme B. Fakae, Godfrey C. Akani, John E. Fa
The Guinean forests of West Africa (GFWA) region is of highest conservation value in Africa and worldwide. The aims of this review are to systematically identify and collate studies focusing on the environment in the region. We found that, after Google Scholar search, in over 112,000 results for 17 disciplines, three countries (Nigeria, Cameroon and Togo) were subjected to much more investigations than the other countries. Guinea, Liberia, and Sierra Leone were the least studied countries, and overall there was a significant West to East increasing trend for all seven considered disciplines (Ecology, Zoology, Botany, Conservation biology, Pollution, Climate change and Ecological economy) in terms of number of results. Within 'Ecology' 'macroecology and biodiversity' was the most studied subdiscipline. Baseline taxonomic studies in 'Zoology' and 'Botany' received little interest, particularly in 2006–2016. For 'Conservation biology', studies focusing on 'protected areas' were more numerous than for any other subsector, followed by 'biodiversity surveys'. Our analysis revealed that there were significantly more studies focusing on forests than on mangrove areas. Our results pointed out that, there is an urgent need for more rigorous taxonomical and fine-scale distribution studies of organisms across the whole region, not only for the traditionally overlooked groups (e.g. invertebrates). It is also stressed that studies of macropatterns in conservation biology research for the region should be performed by more reliable data at the more local scale, given the misuse that has been done by general studies of these limited/biased data for inferring patterns. Long-term longitudinal studies on biodiversity patterns of important forest sites and population biology of selected populations are urgently needed, as these have been almost entirely neglected to date. Crucial issues are still to be solved: for instance, it remains fully unresolved whether wildlife can best be protected through the promotion of human economic development or through integral conservation of important biodiversity areas.



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Molecular Characterization of a Series of Solitary Fibrous Tumors, including Immunohistochemical expression of STAT6 and NATB2-STAT6 Fusion Transcripts, using Reverse Transcriptase(RT)–Polymerase Chain Reaction(PCR) Technique: An Indian Experience

Publication date: Available online 26 August 2017
Source:Pathology - Research and Practice
Author(s): Bharat Rekhi, Omshree Shetty, Parul Tripathi, Prachi Bapat, Mukta Ramadwar, Jyoti Bajpai, Ajay Puri
A solitary fibrous tumor (SFT) is characterized by a diverse clinicopathologic spectrum. Recent studies have unraveled STAT6 as a useful diagnostic immunohistochemical (IHC) marker for a SFT and NAB2-STAT6 as its specific gene fusion transcript.Thirty-three SFTs were tested for STAT6 immunostaining by polymer detection technique. STAT6 immunoexpression was further graded, based on intensity (mild, moderate and strong) and percentage of immunopositive tumor cells, ranging from 1–25%(1+); 26–50%(2+); 51–75%(3+) and in more than 75%(4+) tumor nuclei.These cases along with 17 other tumors were tested for 8 variants of NAB2-STAT6, using qualitative endpoint reverse-transcriptase (RT)-PCR technique. RNA extraction was performed using Recover All Total nucleic acid extraction kit. The selected cases were screened for all the 8 fusion variants, using 8 primer pairs for NAB2 and STAT6 genes.Thirty-three SFTs occurred in 18 men and 15 women (M: F=1.2:1), with age varying from 13–74 years(average=49.6); across various body sites. Immunohistochemically, most SFTs (30/33) (90.9%) displayed moderate to strong immunostaining for STAT6, including 3+ and 4+ immunostaining patterns in 27/33 (81.8%) tumors. By RT-PCR, 30/33(90.9%) cases of SFT were positive for NAB2-STAT6 fusions, including NAB2ex4/STAT6ex2 (7cases), NAB2ex7/STAT6ex2 (7cases), NAB2ex6/STAT6ex3 (6cases), NAB2ex6/SAT6ex16 (4cases), NAB2ex3/STAT6ex19 (4cases), NAB2ex6/STAT6ex17 (single case), NAB2ex4/STAT6ex4 (single case) and NAB2ex6/STAT6ex18 (none). NAB2-STAT6 fusions were not observed in 9 cases of synovial sarcoma, 4 of Ewing sarcoma, 2 of MPNST and 2 cases of dedifferentiated liposarcomas (100% specificity). On comparing with clinical outcomes, more cases (7/11)(63.6%) of classic SFT were associated with favorable outcomes, while more cases(5/8)(62%) of atypical and malignant SFTs were associated with aggressive outcomes.This study reinforces high sensitivity and specificity of NAB2-STAT6 fusion and its correlation with strong and diffuse IHC expression of STAT6 in a SFT, irrespective of its occurrence in various body sites and its histopathologic types. NAB2ex4-STAT6ex2 and NAB2ex7-STAT6ex2 fusions were relatively more frequently observed in our patients. Atypical and malignant SFTs, together, were more frequently associated with relatively aggressive clinical outcomes.



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Congenital Absence of the Palmaris Longus Muscle: A Meta-Analysis Comparing Cadaveric and Function Studies

The aim of our paper was to provide comprehensive data on the prevalence of absence of palmaris longus muscle (PLM) and its anatomical characteristics, and conduct two separate meta-analyses comparing cadaveric and functional studies while identifying variation among different ethnic groups. An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included prevalence of absence of palmaris longus muscle among subjects, ethnicity, laterality, side and gender.

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Intensity-modulated radiotherapy in head and neck cancer — an update for oral and maxillofacial surgeons

Intensity-modulated radiation therapy (IMRT), a relatively new method of delivering radiotherapy, can precisely target a point within a specific tumour and reduce the dose to nearby anatomical structures. This is particularly important in the head and neck where radiotherapy can easily and irreparably damage the salivary glands, spinal cord, and eyes, and where, with increasingly better outcomes and survival, late complications of conventional radiotherapy (including osteoradionecrosis of the cervical spine) can be difficult to manage.

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Diagnostic dilemma between medication-related osteonecrosis and oral squamous cell carcinoma in a mandibular lytic lesion

Osteolytic lesions of the mandible are common, and there are two important differential diagnoses that must be considered: medication-related osteonecrosis of the jaws (MRONJ) and squamous cell carcinoma (SCC). In patients with a history of taking antiresorptive medication as well as risk factors for neoplasia it can be difficult to differentiate between the two. We describe two cases in both of which a mandibular osteolytic lesion was inadequately identified as either MRONJ or SCC because of confusing clinical and histopathological features.

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Angiotensin AT1 receptors modulate the anxiogenic effects of angiotensin (5-8) injected into the rat ventrolateral periaqueductal gray

Publication date: Available online 26 August 2017
Source:Peptides
Author(s): Karina Genaro, Débora Fabris, Helene A. Fachim, Wiliam A. Prado
Losartan and PD 123,319 are non-peptide angiotensin (Ang) receptor antagonists for the AT1 and AT2 subtypes of Ang II receptors, respectively. The tetrapeptide Ang (5-8) is the smallest Ang-peptide that elicits anxiogenic effects on unconditioned and conditioned experimental models upon injection into the ventrolateral column of the periaqueductal gray (vlPAG), and Ang (5-8) can be synthesized (from Ang II or Ang III) and inactivated in this mesencephalic structure. The vlPAG is also known to play a central role in mechanisms of fear and anxiety. We therefore utilized male Wistar rats to examine the effects of losartan and PD 123,319 injections, selective antagonists of the AT1 and AT2 receptors, respectively, into the vlPAG in the elevated plus-maze, a classic rat model of anxiety, and against the anxiogenic effect of Ang (5-8) (0.4 nmol/0.25μL) upon injection into the same region. The anxiolytic profile was dependent on the dose of intra-vlPAG losartan, whereas no effects on experimental anxiety were observed in the plus-maze following PD 123,319 injection. The anxiogenic effect of Ang (5-8) injection into the vlPAG remained unchanged in the PD 123,319-pretreated rats, but the effect did not occur in losartan-pretreated rats. The results led us to suggest that the anxiogenic effect of Ang (5-8) injection into the vlPAG may depend on the local activation of AT1, but not AT2 receptors. Activation of AT1 receptors in structures nearby vlPAG may be tonically involved in fear and experimental anxiety.



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