Species-dependent role of crossmodal connectivity among the primary sensory cortices

Publication date: Available online 9 June 2016
Source:Hearing Research
Author(s): M. Alex Meredith, Stephen G. Lomber
When a major sense is lost, crossmodal plasticity substitutes functional processing from the remaining, intact senses. Recent studies of deafness-induced crossmodal plasticity in different subregions of auditory cortex indicate that the phenomenon is largely based on the "unmasking" of existing inputs. However, there is not yet a consensus on the sources or effects of crossmodal inputs to primary sensory cortical areas. In the present review, a rigorous re-examination of the experimental literature indicates that connections between different primary sensory cortices consistently occur in rodents, while primary-to-primary projections are absent/inconsistent in non-rodents such as cats and monkeys. These observations suggest that crossmodal plasticity that involves primary sensory areas are likely to exhibit species-specific distinctions.

Graphical abstract

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Neural correlates of auditory scale illusion

Publication date: Available online 9 June 2016
Source:Hearing Research
Author(s): Shinya Kuriki, Ryousuke Numao, Iku Nemoto
The auditory illusory perception "scale illusion" occurs when ascending and descending musical scale tones are delivered in a dichotic manner, such that the higher or lower tone at each instant is presented alternately to the right and left ears. Resulting tone sequences have a zigzag pitch in one ear and the reversed (zagzig) pitch in the other ear. Most listeners hear illusory smooth pitch sequences of up-down and down-up streams in the two ears separated in higher and lower halves of the scale. Although many behavioral studies have been conducted, how and where in the brain the illusory percept is formed have not been elucidated. In this study, we conducted functional magnetic resonance imaging using sequential tones that induced scale illusion (ILL) and those that mimicked the percept of scale illusion (PCP), and we compared the activation responses evoked by those stimuli by region-of-interest analysis. We examined the effects of adaptation, i.e., the attenuation of response that occurs when close-frequency sounds are repeated, which might interfere with the changes in activation by the illusion process. Results of the activation difference of the two stimuli, measured at varied tempi of tone presentation, in the superior temporal auditory cortex were not explained by adaptation. Instead, excess activation of the ILL stimulus from the PCP stimulus at moderate tempi (83 and 126 bpm) was significant in the posterior auditory cortex with rightward superiority, while significant prefrontal activation was dominant at the highest tempo (245 bpm). We suggest that the area of the planum temporale posterior to the primary auditory cortex is mainly involved in the illusion formation, and that the illusion-related process is strongly dependent on the rate of tone presentation.



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Species-dependent role of crossmodal connectivity among the primary sensory cortices

Publication date: Available online 9 June 2016
Source:Hearing Research
Author(s): M. Alex Meredith, Stephen G. Lomber
When a major sense is lost, crossmodal plasticity substitutes functional processing from the remaining, intact senses. Recent studies of deafness-induced crossmodal plasticity in different subregions of auditory cortex indicate that the phenomenon is largely based on the "unmasking" of existing inputs. However, there is not yet a consensus on the sources or effects of crossmodal inputs to primary sensory cortical areas. In the present review, a rigorous re-examination of the experimental literature indicates that connections between different primary sensory cortices consistently occur in rodents, while primary-to-primary projections are absent/inconsistent in non-rodents such as cats and monkeys. These observations suggest that crossmodal plasticity that involves primary sensory areas are likely to exhibit species-specific distinctions.

Graphical abstract

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A case report of anorectal malignant melanoma with mucosal skipped lesion.

A case report of anorectal malignant melanoma with mucosal skipped lesion.

Int J Surg Case Rep. 2016 Apr 30;24:206-210

Authors: Arakawa K, Kiyomatsu T, Ishihara S, Ikemura M, Hojo D, Takiyama H, Murono K, Otani K, Yasuda K, Nishikawa T, Tanaka T, Kawai K, Hata K, Nozawa H, Yamaguchi H, Watanabe T

Abstract
INTRODUCTION: We report our experience involving a case of relatively rare anorectal malignant melanoma with skipped lesion.
PRESENTATION OF CASE: The patient was a 72-year-old man who had visited a local clinic complaining of a mass in the anal region, whereupon he was referred to our hospital on suspicion of a malignant melanoma. Close examination revealed a 25-mm black type 1 tumor one-third the size of the circumference of the anal canal and located externally to it. We performed transanal resection of the tumor and confirmed a diagnosis of malignant melanoma. Notably, multiple macular black lesions spaced away from the main lesion were observed during surgery in half of the circumference of the anal canal, from the tumor to the pectinate line. A biopsy of the area also revealed malignant melanoma; therefore, we performed abdominoperineal resection. Pathological diagnosis indicated a submucosal depth; the patient was thus diagnosed with T4 N2c M0 stage IIIb malignant melanoma and was followed on an outpatient basis.
DISCUSSION: Patients with anorectal malignant melanoma have very poor prognoses owing to early lymph node metastasis and hematogenous metastasis. Our case illustrates that small anorectal malignant melanoma lesions can spread from the main lesion and invade the mucosa; examinations may sometimes miss such skipped lesions.
CONCLUSION: Skipped lesions can occur in anorectal melanomas; thus, careful scrutiny of such lesions is required. Moreover, lesion resection is critical for anorectal malignant melanomas.

PMID: 27281362 [PubMed - as supplied by publisher]

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Primary pulmonary melanoma: a report of two cases.

Related Articles

Primary pulmonary melanoma: a report of two cases.

World J Surg Oncol. 2015;13:274

Authors: Watanabe M, Yamamoto H, Hashida S, Soh J, Sugimoto S, Toyooka S, Miyoshi S

Abstract
Malignant melanoma is a refractory malignancy with a dismal prognosis. It generally arises from the skin in most cases, and cases of primary pulmonary malignant melanoma are rare and often behave aggressively. We have treated two cases of localized primary pulmonary malignant melanoma using surgical resection. Pulmonary malignant melanomas often metastasize to the brain and liver; one of our cases exhibited metastasis to the cecum at about 8 months after surgery. Because cutaneous melanomas often carry activating mutations in the BRAF gene (V600E), we performed a BRAF mutational analysis using direct sequencing for both of these tumors arising from the lung. However, no BRAF mutations were detected. We detected a p53 mutation, which was thought to be a potential somatic mutation, in one of the two cases using a sequencing panel targeting 20 lung cancer-related genes. Although we also checked the expression of programmed death ligand 1 (PD-L1) on the surface of the tumor cells by immunohistochemical testing, neither of our two cases expressed PD-L1. Further molecular analyses may uncover the characteristics of primary pulmonary malignant melanomas.

PMID: 26376781 [PubMed - indexed for MEDLINE]

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Curcumin: A new candidate for melanoma therapy?

Curcumin: A new candidate for melanoma therapy?

Int J Cancer. 2016 Jun 9;

Authors: Mirzaei H, Naseri G, Rezaee R, Mohammadi M, Banikazemi Z, Reza Mirzaei H, Salehi H, Peyvandi M, Pawelek JM, Sahebkar A

Abstract
Melanoma remains among the most lethal cancers and, in spite of great attempts that have been made to increase the life span of patients with metastatic disease, durable and complete remissions are rare. Plants and plant extracts have long been used to treat a variety of human conditions; however, in many cases, effective doses of herbal remedies are associated with serious adverse effects. Curcumin is a natural polyphenol that shows a variety of pharmacological activities including anti-cancer effects, and only minimal adverse effects have been reported for this phytochemical. The anti-cancer effects of curcumin are the result of its anti-angiogenic, pro-apoptotic, and immunomodulatory properties. At the molecular and cellular level, curcumin can blunt epithelial-to-mesenchymal transition and affect many targets that are involved in melanoma initiation and progression (e.g. BCl2, MAPKS, p21 and some microRNAs). However, curcumin has a low oral bioavailability that may limit its maximal benefits. The emergence of tailored formulations of curcumin and new delivery systems such as nanoparticles, liposomes, micelles and phospholipid complexes has led to the enhancement of curcumin bioavailability. Although in vitro and in vivo studies have demonstrated that curcumin and its analogues can be used as novel therapeutic agents in melanoma, curcumin has not yet been tested against melanoma in clinical practice. In this review, we summarized reported anti-melanoma effects of curcumin as well as studies on new curcumin formulations and delivery systems that show increased bioavailability. Such tailored delivery systems could pave the way for enhancement of the anti-melanoma effects of curcumin. This article is protected by copyright. All rights reserved.

PMID: 27280688 [PubMed - as supplied by publisher]

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Ortner's Syndrome-A Rare Cause of Hoarseness: Its Importance to an Otorhinolaryngologist.

Ortner's Syndrome-A Rare Cause of Hoarseness: Its Importance to an Otorhinolaryngologist.

Iran J Otorhinolaryngol. 2016 Mar;28(85):163-7

Authors: Sarin V, Bhardwaj B

Abstract
INTRODUCTION: Cardiovocal hoarseness (Ortner's syndrome) is hoarseness of voice due to recurrent laryngeal nerve involvement secondary to cardiovascular disease. Recurrent laryngeal nerve in its course (especially the left side) follows a path that brings it in close proximity to numerous structures. These structures interfere with its function by pressure or by disruption of the nerve caused by disease invading the nerve. However painless asymptomatic intramural hematoma of the aortic arch, causing hoarseness as the only symptom, is a rare presentation as in this case.
CASE REPORT: We report a case of silent aortic intramural hematoma which manifested as hoarseness as the only presenting symptom. A detailed history and thorough clinical examination could not reveal the pathology of hoarseness. The cause of hoarseness was diagnosed as aortic intramural hematoma on contrast computed tomography. Thus the patient was diagnosed as case of cardiovocal hoarseness (Ortner's syndrome) secondary to aortic intramural hematoma.
CONCLUSION: A silent aortic intramural hematoma with hoarseness as the only presenting symptom is very rare. This particular case report holds lot of significance to an otolaryngologist as he should be aware of this entity and should always consider it in the differential diagnosis of hoarseness.

PMID: 27280105 [PubMed]

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