Corticothalamic Projections Gate Alpha Rhythms in the Pulvinar

Two types of corticothalamic (CT) terminals reach the pulvinar nucleus of the thalamus, and their distribution varies according to the hierarchical level of the cortical area they originate from. While type 2 terminals are more abundant at lower hierarchical levels, terminals from higher cortical areas mostly exhibit type 1 axons. Such terminals also evoke different excitatory postsynaptic potential dynamic profiles, presenting facilitation for type 1 and depression for type 2. As the pulvinar is involved in the oscillatory regulation between intercortical areas, fundamental questions about the role of these different terminal types in the neuronal communication throughout the cortical hierarchy are yielded. Our theoretical results support that the co-action of the two types of terminals produces different oscillatory rhythms in pulvinar neurons. More precisely, terminal types 1 and 2 produce alpha-band oscillations at a specific range of connectivity weights. Such oscillatory activity is generated by an unstable transition of the balanced state network’s properties that it is found between the quiescent state and the stable asynchronous spike response state. While CT projections from areas 17 and 21a are arranged in the model as the empirical proportion of terminal types 1 and 2, the actions of these two cortical connections are antagonistic. As area 17 generates low-band oscillatory activity, cortical area 21a shifts pulvinar responses to stable asynchronous spiking activity and vice versa when area 17 produces an asynchronous state. To further investigate such oscillatory effects through corticothalamo-cortical projections, the transthalamic pathway, we created a cortical feedforward network of two cortical areas, 17 and 21a, with CT connections to a pulvinar-like network with two cortico-recipient compartments. With this model, the transthalamic pathway propagates alpha waves from the pulvinar to area 21a. This oscillatory transfer ceases when reciprocal connections from area 21a reach the pulvinar, closing the CT loop. Taken together, results of our model suggest that the pulvinar shows a bi-stable spiking activity, oscillatory or regular asynchronous spiking, whose responses are gated by the different activation of cortico-pulvinar projections from lower to higher-order areas such as areas 17 and 21a.

Cortex: Topography and Organization

The cerebral cortex is involved in various simple and complex activities. It consists of layers of neuronal cell bodies (ie, gray matter) that are organized into gyri (convolutions).The cortex can be divided into functional components in several ways. Various schemes are based on function, cytoarchitecture, topography, or Brodmann areas. The terminology can be confusing because the same area of cortex could be designated by several names. For instance, Brodmann area 17 is also called the primary visual cortex, the striate cortex, and the calcarine cortex. Brodmann designated 52 regions of the cerebral cortex according to cytoarchitecture.

Corticothalamic Projections Gate Alpha Rhythms in the Pulvinar

Two types of corticothalamic (CT) terminals reach the pulvinar nucleus of the thalamus, and their distribution varies according to the hierarchical level of the cortical area they originate from. While type 2 terminals are more abundant at lower hierarchical levels, terminals from higher cortical areas mostly exhibit type 1 axons. Such terminals also evoke different excitatory postsynaptic potential dynamic profiles, presenting facilitation for type 1 and depression for type 2. As the pulvinar is involved in the oscillatory regulation between intercortical areas, fundamental questions about the role of these different terminal types in the neuronal communication throughout the cortical hierarchy are yielded. Our theoretical results support that the co-action of the two types of terminals produces different oscillatory rhythms in pulvinar neurons. More precisely, terminal types 1 and 2 produce alpha-band oscillations at a specific range of connectivity weights. Such oscillatory activity is generated by an unstable transition of the balanced state network’s properties that it is found between the quiescent state and the stable asynchronous spike response state. While CT projections from areas 17 and 21a are arranged in the model as the empirical proportion of terminals types 1 and 2, the actions of these two cortical connections are antagonistic. As area 17 generates low-band oscillatory activity, cortical area 21a shifts pulvinar responses to stable asynchronous spiking activity and vice-versa when area 17 produces an asynchronous state. To further investigate such oscillatory effects through corticothalamo-cortical projections, the transthalamic pathway, we created a cortical feedforward network of two cortical areas, 17 and 21a, with CT connections to a pulvinar-like network. With this model, the transthalamic pathway propagates alpha waves from the pulvinar to area 21a. This oscillatory transfer ceases when reciprocal connections from area 21a reach the pulvinar, closing the cortico-thalamic loop. Taken together, results of our model suggest that the pulvnar shows a bi-stable spiking activity, oscillatory or regular asynchronous spiking, whose responses are gated by the different activation of cortico-pulvinar projections from lower to higher-order areas such as areas 17 and 21a.

PENULISAN KONSONAN RANGKAP (SOKUON) PADA BAHASA PERCAKAPAN DALAM KOMIK BAHASA JEPANG

Double Consonant writing in Japanese marked by Hiragana or Katakana written (?/?). Sokuon has been used many in daily comic conversation to emphazise or strengthen the speech. As the consequence, the outcome of Japanese written becomes unstandard since there is morphologically change. That is why a research has been done using comic titled Crows volume 1 by Takahashi Hiroshi to represent Japanese Comic that generally has the same sokuon written structure in daily conversation. Analysis result shows there is 1 sokuon written in the beginning, 7 sokuons in the middle, and there area 17 sokuons in the end, also there area 16 sokuons in between 2 words. Those data has been analyzed using The Prominen Theory and The Shukuyaku-kei Formation Theory. Future expectation is to expand this research through other aspect of speech that use sokuon seen from the context and function aspect. Keywords: Double Consonant, Sokuon, Daily Language Communication, Comic.

Local organization of spatial frequency tuning dynamics in the cat visual areas 17 and 18

In cat area 17/18, we found that a local pool of neurons with similar spatial frequency (SF) tunings shows diverse but organized dynamics. Our results suggest that, in the presence of organized tuning diversity within an SF domain, the cortical SF organization remains stable over response time in these areas. Laminar analysis suggests that intracortical mechanisms contribute to generating SF dynamics inside the input layer but do not further shape it outside this layer.

Pulvinar Modulates Synchrony across Visual Cortical Areas

The cortical visual hierarchy communicates in different oscillatory ranges. While gamma waves influence the feedforward processing, alpha oscillations travel in the feedback direction. Little is known how this oscillatory cortical communication depends on an alternative route that involves the pulvinar nucleus of the thalamus. We investigated whether the oscillatory coupling between the primary visual cortex (area 17) and area 21a depends on the transthalamic pathway involving the pulvinar in cats. To that end, visual evoked responses were recorded in areas 17 and 21a before, during and after inactivation of the pulvinar. Local field potentials were analyzed with Wavelet and Granger causality tools to determine the oscillatory coupling between layers. The results indicate that cortical oscillatory activity was enhanced during pulvinar inactivation, in particular for area 21a. In area 17, alpha band responses were represented in layers II/III. In area 21a, gamma oscillations, except for layer I, were significantly increased, especially in layer IV. Granger causality showed that the pulvinar modulated the oscillatory information between areas 17 and 21a in gamma and alpha bands for the feedforward and feedback processing, respectively. Together, these findings indicate that the pulvinar is involved in the mechanisms underlying oscillatory communication along the visual cortex.

A preliminary study on the ultrasonic manifestations of peripulmonary lesions of non-critical novel coronavirus pneumonia (COVID-19)

Background: Ultrasound is used to observe the imaging manifestations of COVID-19 in order to provide reference for real-time bedside evaluation.Purpose: To explore the ultrasonic manifestations of peripulmonary lesions of non-critical COVID-19, so as to provide reference for clinical diagnosis and efficacy evaluation.Materials and Methods: The clinical and ultrasonic data of 20 patients with clinically diagnosed non-critical COVID-19 treated in Xi'an Chest Hospital during January and February 2020 were retrospectively analyzed. Conventional two-dimensional ultrasound and color Doppler ultrasound were used to observe the characteristics of lesions. Results: All 20 patients (40 lungs and 240 lung areas) had a history of travel, residence or close contact in/with Wuhan, and 5 of them caught COVID-19 after family gatherings. Lesions tended to occur in both lungs. Lesions in the lung areas: 14 in L1+R1 area (14/40), 17 in L2+R2 area (17/40), 17 in L3+R3 area (17/40), 17 in L4+R4 area (17/40), 20 in L5+R5 area (20/40), and 28 in L6+R6 area (28/40). Lesion types: rough and discontinuous pleural line (36/240), subpleural consolidation (53/240), air bronchogram sign or air bronchiologram sign in subpleural peripleural consolidation (37/240), visible B lines (91/240), localized pleural thickening (19/240), localized pleural effusion (24/240), poor blood flow in the consolidation detected by color Doppler ultrasound (50/53).Conclusion: The non-critical COVID-19 has characteristic ultrasonic manifestations, which are visible in the posterior and inferior areas of the lung. The lesions are mainly characterized by a large number of B lines, subpleural pulmonary consolidation and poor blood flow. Lung ultrasound can provide reference for the clinical diagnosis and efficacy evaluation. Chinese Clinical Trial Registry: ChiCTR2000030032Approval for Scientific Research Project: No. 2020-S0001

The dynamics change of fishpond land into settlement the east coast of Surabaya 2004-2017

Surabaya rapidly developed to the east region which grew the formal/non-formal settlement in Pamurbaya. This area is dominated by fishpond that is converted into settlement area. This research aims to observe the dynamic change of fishpond which is already converted into settlement area in the east coast of Surabaya, during 2004-2017. This research applies landsat image 7 ETM+ and landsat 8 OLI with overlay method which is analyzed descriptively. During 2004-2017, the settlement area had been developing for 218,296 Ha or 88% and during the same years, the fishpond had been reducing for 531,639 Ha or 24%, this reduction can change into mangrove or settlement area. During 13 years, the change of fishpond into settlement area is 15%. The research area which experienced the change is the fishpond of Kejawan Putih (24%), Medokan Ayu area (17%), and Keputih area (16%).