A framework for the first‑person internal sensation of visual perception in mammals and a comparable circuitry for olfactory perception in Drosophila

Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception

Real-world treatment outcomes in patients with metastatic Merkel cell carcinoma treated with chemotherapy in the USA

Aim: This retrospective study of patients in the USA with metastatic Merkel cell carcinoma (mMCC) aimed to assess patient responses to second-line and later (2L+) and first-line (1L) chemotherapy. Patients & methods: Out of 686 patients with MCC identified in The US Oncology Network, 20 and 67 patients with mMCC qualified for the 2L+ and 1L study, respectively; the primary analysis population was restricted to immunocompetent patients. Results: In the 2L+ primary analysis population, objective response rate (ORR) was 28.6%, median duration of response (DOR) was 1.7 months and median progression-free survival was 2.2 months. In the 1L primary analysis population, ORR was 29.4%, median DOR was 6.7 months and median progression-free survival was 4.6 months. Conclusion: The low ORR and brief DOR underscore the need for novel therapies