Cortical sensory processing is modulated by behavioral and cognitive states. How the modulation is achieved through impacting synaptic circuits remains largely unknown. In awake mouse auditory cortex, we reported that sensory-evoked spike responses of layer 2/3 (L2/3) excitatory cells were scaled down with preserved sensory tuning when animals transitioned from quiescence to active behaviors, while L4 and thalamic responses were unchanged. Whole-cell voltage-clamp recordings further revealed that tone-evoked synaptic excitation and inhibition exhibited a robust functional balance. Changes of behavioral state caused scaling down of excitation and inhibition at an approximately equal level in L2/3 cells, but no synaptic changes in L4 cells. This laminar-specific gain control could be attributed to an enhancement of L1–mediated inhibitory tone, with L2/3 parvalbumin inhibitory neurons suppressed as well. Thus, L2/3 circuits can adjust the salience of output in accordance with momentary behavioral demands while maintaining the sensitivity and quality of sensory processing.

Imatinib demonstrated significant activity in patients with metastatic melanoma harboring genetic c-Kit aberrations, with an overall response rate of 23.3%. Escalation to 800 mg/d could not restore disease control.

Purpose: KIT aberrations were described in acral and mucosal melanomas in largely Caucasian populations. Asian populations are more prone to develop acral and mucosal than cutaneous melanomas, and may harbor a high frequency of KIT aberrations.Experimental Design: Melanoma subtypes (n ¼ 502) were analyzed histologically to determine melanoma subtype. Tissue samples were analyzed for mutations in exons 9, 11, 13, 17, and 18 of KIT gene in genomic DNA by PCR amplification and Sanger sequencing. The copy numbers of the KIT gene were analyzed by quantitative PCR, and protein expression levels of KIT (CD117) were determined by immunohistochemistry.Results: The most common melanoma subtypes were acral (38.4%) and mucosal (33.3%) melanomas in this population. The overall incidence of somatic mutations within the KIT gene was 10.8% (54/502), and all subtypes of melanoma contained KIT mutations. Increases in KIT gene copy numbers were correlated to CD117 overexpression. The genetic mutations of KIT were unrelated to the age, gender, stage, thickness, and ulceration of primary melanomas. Importantly, the overall survival of melanoma patients with KIT mutations (P ¼ 0.001) or with KIT aberrations (mutation plus amplification, P ¼ 0.0002) was significantly shorter than that of patients without such alterations.Conclusion: In China, the prevalent melanomas are acral and mucosal melanomas. KIT mutations are detected in all melanoma subtypes. Our study suggests that increases in KIT gene copy numbers, but not KIT mutations, may be correlated to CD117 overexpression. For the first time, our study suggests that genetic KIT aberration is an adverse prognostic factor for melanoma. Clin Cancer Res; 17(7); 1684-91. Ó2011 AACR.

Sarcomas are a group of rare solid tumours arising from mesenchymal or connective tissue. This review focuses on soft tissue sarcoma and covers general topics such as the epidemiology, age distribution, site of disease, histogenesis, histological subtypes, prognosis and outcome of treatment. In more detail, the article reviews current systemic treatment standards and selected adverse events of agents such as doxorubicin, ifosfamide, trabectedin and pazopanib, and briefly highlights some drugs that are used off-label in specific subtypes of sarcoma.