Intracellular Response Properties of Units in the Dorsal Cochlear Nucleus of Unanesthetized Decerebrate Gerbil

1997 ◽  
Vol 77 (5) ◽  
pp. 2549-2572 ◽  
Author(s):  
Jiang Ding ◽  
Herbert F. Voigt
Keyword(s):  
Dorsal Cochlear Nucleus ◽  
Type I ◽  
Type Ii ◽  
Response Properties ◽  
Type Iii ◽  
Type Iv ◽  
Rate Versus ◽  
Lower Maximum ◽  
Intracellular Response ◽  
Acoustic Responses

Ding, Jiang and Herbert F. Voigt. Intracellular response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil. J. Neurophysiol. 77: 2549–2572, 1997. Intracellular recording experiments on the dorsal cochlear nuclei of unanesthetized decerebrate gerbils were conducted. Acceptable recordings were those in which resting potentials were −50 mV or less and action potentials (APs) were ≥40 mV. Responses to short-duration tones and noise, and to current pulses delivered via recording electrodes, were acquired. Units were classified according to the response map scheme (types I–IV). Ninety-two acceptable recordings were made. Most units had simple APs (simple-spiking units); nine units had both simple and complex APs, which are bursts of spikes embedded on slow, transient depolarizations (complex-spiking units). Of 83 simple-spiking units, 46 were classified as follows: type I/III (9 units), type II (9 units), type III (25 units), type IV (2 units), and type IV-T (1 unit). One complex-spiking unit was classifiable (a type III unit); six were unclassifiable because of weak acoustic responses. Classifying 39 other simple-spiking units and 2 complex-spiking units was impossible, because they were either injured or lost before sufficient data were acquired. Many simple-spiking units showed depolarization or hyperpolarization (∼5–10 mV) during acoustic stimulation; some were hyperpolarized during the stimulus-off period. Type I/III units were not hyperpolarized during off-best-frequency (off-BF) stimulation. In contrast, many type II units were hyperpolarized by off-BF frequencies, suggesting that they received strong inhibitory sideband inputs. When inhibited, some type III units were hyperpolarized. Type IV units were hyperpolarized during inhibition even at low levels (<60 dB SPL); sustained depolarizations occurred only at higher levels, suggesting that they receive strong inhibitory and weak excitatory inputs. Several intracellular response properties were statistically different from those of extracellularly recorded units. Intracellularly recorded type II units had higher thresholds and lower maximum BF-driven and noise-driven rates than their extracellularly recorded counterparts. Type I/III units recorded intracellularly had lower maximum BF-driven rates. Type III units recorded intracellularly had higher maximum noise rates compared with those recorded extracellularly. Weaker acoustic responses most likely result from membrane disruption, but heightened responses may be related to weakened chloride-channel-dependent inhibition due to altered driving forces resulting from KCl leakage. Firing rates of simple-spiking units increased monotonically with increasing levels of depolarizing current pulses. In contrast, many complex-spiking units responded nonmonotonically to depolarizing current injection. The monotonic rate-versus-current curves and the nonmonotonic rate-versus-sound level curves of type IV and III units suggest that the acoustic behavior is the result of extrinsic inhibitory inputs and not due solely to intrinsic membrane properties.

Response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil

1996 ◽  
Vol 75 (4) ◽  
pp. 1411-1431 ◽  
Author(s):  
K. A. Davis ◽  
J. Ding ◽  
T. E. Benson ◽  
H. F. Voigt
Keyword(s):  
Dorsal Cochlear Nucleus ◽  
Type I ◽  
Type Ii ◽  
Decerebrate Cat ◽  
Excitatory Response ◽  
Type Iii ◽  
Type Iv ◽  
Noise Type ◽  
Rate Versus ◽  
Excitatory Responses

1. The electrophysiological responses of single units in the dorsal cochlear nucleus of unanesthetized decerebrate Mongolian gerbil (Meriones unguiculatus) were recorded. Units were classified according to the response map scheme of Evans and Nelson as modified by Young and Brownell, Young and Voigt, and Shofner and Young. Type II units have a V-shaped excitatory response map similar to typical auditory nerve tuning curves but little or no spontaneous activity (SpAc < 2.5 spikes/s) and little or no response to noise. Type I/III units also have a V-shaped excitatory map and SpAc < 2.5 spikes/s, but have an excitatory response to noise. Type III units have a V-shaped excitatory map with inhibitory sidebands, SpAc > 2.5 spikes/s, and an excitatory response to noise. Type IV-T units typically also have a V-shaped excitatory map with inhibitory sidebands, but have a highly nonmonotonic rate versus level response to best frequency (BF) tones like type IV units, SpAc > 2.5 spikes/s, and an excitatory response to noise. Type IV units have a predominantly inhibitory response map above an island of excitation of BF, SpAc > 2.5 spikes/s, and an excitatory response to noise. We present results for 133 units recorded with glass micropipette electrodes. The purpose of this study was to establish a normative response map data base in this species for ongoing structure/function and correlation studies. 2. The major types of units (type II, type I/III, type III, type IV-T, and type IV) found in decerebrate cat are found in decerebrate gerbil. However, the percentage of type II (7.5%) and type IV (11.3%) units encountered are smaller and the percentage of type III (62.4%) units is larger in decerebrate gerbil than in decerebrate cat. In comparison, Shofner and Young found 18.5% type II units, 30.6% type IV units, and 23.1% type III units using metal electrodes. 3. Two new unit subtypes are described in gerbil: type III-i and type IV-i units. Type III-i units are similar to type III units except that type III-i units are inhibited by low levels of noise and excited by high levels of noise whereas type III units have strictly excitatory responses to noise. Type IV-i units are similar to type IV units except that type IV-i units are excited by low levels of noise and become inhibited by high levels of noise whereas type IV units have strictly excitatory responses to noise. Type III-i units are approximately 30% of the type III population and type IV-i units are approximately 50% of the type IV population. 4. On the basis of the paucity of classic type II units and the reciprocal responses to broadband noise of type III-i and type IV-i units, we postulate that some gerbil type III-i units are the same cell type and have similar synaptic connections as cat type II units. 5. Type II and type I/III units are distinguished from one another on the basis of both their relative noise response, rho, and the normalized slope of the BF tone rate versus level functions beyond the first maximum. Previously, type II units were defined to be those nonspontaneously active units with rho values < 0.3 where rho is defined as the ratio of the maximum noise response minus spontaneous rate to the maximum BF tone response minus spontaneous rate. In the gerbil, the average rho value for type II units is 0.25, although a few values are > 0.3, and the rate-level curves are consistently nonmonotonic with normalized slopes steeper than than -0.007/dB. The average rho value for type I/III units is 0.54, although a few values are < 0.3, and the rate-level curves tend to saturate with slopes shallower than -0.006/dB. In general, the response properties of type II units recorded in gerbil are similar to those recorded in decerebrate cat. 6. In comparison to decerebrate cat, the lower percentage of type IV units recorded in decerebrate gerbil may be due to a species difference (a reduced number of type II units in gerbil) or an electrode bias.

Acoustic and Current-Pulse Responses of Identified Neurons in the Dorsal Cochlear Nucleus of Unanesthetized, Decerebrate Gerbils

1999 ◽  
Vol 82 (6) ◽  
pp. 3434-3457 ◽  
Author(s):  
Jiang Ding ◽  
Thane E. Benson ◽  
Herbert F. Voigt
Keyword(s):  
Cell Morphology ◽  
Giant Cells ◽  
Dorsal Cochlear Nucleus ◽  
Membrane Properties ◽  
Type I ◽  
Fusiform Cell ◽  
Response Properties ◽  
Type Iii ◽  
Acoustic Responses ◽  
Cartwheel Cells

In an effort to establish relationships between cell physiology and morphology in the dorsal cochlear nucleus (DCN), intracellular single-unit recording and marking experiments were conducted on decerebrate gerbils using horseradish peroxidase (HRP)- or neurobiotin-filled micropipettes. Intracellular responses to acoustic (tone and broadband noise bursts) and electric current-pulse stimuli were recorded and associated with cell morphology. Units were classified according to the response map scheme (type I to type V). Results from 19 identified neurons, including 13 fusiform cells, 2 giant cells, and 4 cartwheel cells, reveal correlations between cell morphology of these neurons and their acoustic responses. Most fusiform cells (8/13) are associated with type III unit response properties. A subset of fusiform cells was type I/III units (2), type III-i units (2), and a type IV-T unit. The giant cells were associated with type IV-i unit response properties. Cartwheel cells all had weak acoustic responses that were difficult to classify. Some measures of membrane properties also were correlated with cell morphology but to a lesser degree. Giant cells and all but one fusiform cell fired only simple action potentials (APs), whereas all cartwheel cells discharged complex APs. Giant and fusiform cells all had monotonic rate versus current level curves, whereas cartwheel cells had nonmonotonic curves. This implies that inhibitory acoustic responses, resulting in nonmonotonic rate versus sound level curves, are due to local inhibitory interactions rather than strictly to membrane properties. A complex-spiking fusiform cell with type III unit properties suggests that cartwheel cells are not the only complex-spiking cells in DCN. The diverse response properties of the DCN′s fusiform cells suggests that they are very sensitive to the specific complement of excitatory and inhibitory inputs they receive.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

scholarly journals Brachial supporting structure of Spiriferida (Brachiopoda)

2020 ◽  
pp. 1-15
Author(s):  
Zhiwei Yuan ◽  
Wen Guo ◽  
Dan Lyu ◽  
Yuanlin Sun
Keyword(s):  
Mantle Cavity ◽  
Family Type ◽  
Type I ◽  
Type Ii ◽  
Feeding Apparatus ◽  
Single Family ◽  
Supporting Structure ◽  
Type Iii ◽  
Type Iv ◽  
Evolutionary Lineages

Abstract The filter-feeding organ of some extinct brachiopods is supported by a skeletal apparatus called the brachidium. Although relatively well studied in Atrypida and Athyridida, the brachidial morphology is usually neglected in Spiriferida. To investigate the variations of brachidial morphology in Spiriferida, 65 species belonging to eight superfamilies were analyzed. Based on the presence/absence of the jugal processes and normal/modified primary lamellae of the spiralia, four types of brachidium are recognized. Type-I (with jugal processes) and Type-II (without jugal processes), both having normal primary lamellae, could give rise to each other by losing/re-evolving the jugal processes. Type-III, without jugal processes, originated from Type-II through evolution of the modified lateral-convex primary lamellae, and it subsequently gave rise to Type-IV by evolving the modified medial-convex primary lamellae. The evolution of brachidia within individual evolutionary lineages must be clarified because two or more types can be present within a single family. Type-III and Type-IV are closely associated with the prolongation of the crura, representing innovative modifications of the feeding apparatus in response to possible shift in the position of the mouth towards the anterior, allowing for more efficient feeding on particles entering the mantle cavity from the anterior gape. Meanwhile, the modified primary lamellae adjusted/regulated the feeding currents. The absence of spires in some taxa with Type-IV brachidium might suggest that they developed a similar lophophore to that in some extant brachiopods, which can extend out of the shell.

scholarly journals Types of Lens Structure in Intumescent Cataract

2018 ◽  
Vol 15 (2S) ◽  
pp. 153-159
Author(s):  
E. S. Pirogova ◽  
O. L. Fabrikantov ◽  
S. I. Nikolashin
Keyword(s):  
Irrigation System ◽  
Anterior Segment ◽  
Type I ◽  
Type Ii ◽  
Large White ◽  
Type Iii ◽  
Associated Diseases ◽  
Type Iv ◽  
The Mean ◽  
Anatomical Parameters

Purpose: to study the structure of the swelling lens, the dependence of its anatomical parameters on the nucleus sizes and density, patients’ age.Patients and methods. 52 patients with intumescent mature cataract were examined. All patients underwent phacoemulsification with a two-stage continuous circular capsulorhexis. After the 2–2.5 mm capsulorhexis had been created, the liquid lenticular masses were removed from the anterior and posterior lens compartment with the aspiration/irrigation system. Visually we determined the size of the nucleus, its color and density according to Buratto’s classification.Results. When performing this work 4 types of the swelling lens structure were revealed. Type I — a small emerging white nucleus with large amount of liquid lenticular masses in the anterior and posterior lens compartment, II degree of density according to Buratto’s classification. The mean age was 49.09 ± 3.19 years old. The related ophthalmic diseases accounted for 36.4%. Type II — a large white nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. III degree of density according to Buratto’s classification. The mean age was 71.00 ± 1.92 years old. Associated diseases — 84.6%. Type III — a large brown nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. IV degree of density according to Buratto’s classification. The mean age was 75.84 ± 1.46 years old. Associated diseases — 100%. Type IV — a small, very dense, brown nucleus with liquid lenticular masses. V degree of density according to Buratto’s classification. The mean age was 77.33 ± 2.49 years old. Associated diseases — 100%.Conclusion. 4 types of lens structure in intumescent cataract were described depending on the nucleus size, density, the amount of the lenticular masses. By means of UBM method, it was shown that intumescent cataract is accompanied with the alterations of the ocular anterior segment parameters, which depend on the type of lens structure. It was revealed that the types of swelling lens structure are directly connected to the patients’ age: mean age of patients with type I — 49.09 ± 3.19 years old, with type II — 71.00 ± 1.92, with type III — 75.84 ± 1.46, with type IV — 77.33 ± 2.49 years old. 

scholarly journals Relationship Between Pulmonary Hamartoma and Bronchus: Multislice Spiral Computed Tomography Findings

2021 ◽  
Author(s):  
Ping Wang ◽  
Heng Ma ◽  
Qinglin Yang ◽  
Chengzhou Zhang
Keyword(s):  
Computed Tomography ◽  
Spiral Computed Tomography ◽  
Type I ◽  
Tumor Type ◽  
Type Ii ◽  
Spiral Computed ◽  
Type Iii ◽  
Multislice Spiral Computed Tomography ◽  
Type Iv ◽  
Sign Type

Abstract Objective The aim of the present study is to investigate the relationship between pulmonary hamartomas (PHs) and bronchi on multislice spiral computed tomography (MSCT) images. Methods The MSCT scans of 218 PHs from 216 pathologically confirmed patients were reviewed. The PHs were divided into two groups, namely, the central endobronchial and intraparenchymal groups, in accordance with location. Multiplanar reconstruction was used to demonstrate PH–bronchus relationship patterns. The PH–bronchus relationships in the intraparenchymal group were classified into five patterns: type I, the bronchus was cut off by the tumor; type II, the bronchus was contained within the tumor (air bronchogram sign); type III, the bronchus ran at the tumor periphery or was compressed by the tumor; and type IV, no tumor–bronchus relationship was observed. Results Nine (4.1%) PHs were assigned to the central endobronchial group and 209 (95.9%) PHs were assigned to the intraparenchymal group. In the endobronchial group, 1 (11.1%) PH was located in the trachea with the partial stenosis of the trachea, whereas the remaining 8 (88.9%) PHs were located in the lobar or segmental bronchus with the complete occlusion of the corresponding bronchus. In the intraparenchymal group, type IV (147, 70.3%) was most common pattern, followed by type III (54, 25.8%). Type I (8, 3.8%) was rare, and type II was not observed. Conclusion Central endobronchial PHs often obstructed bronchi, whereas only a few intraparenchymal PHs cut off bronchi. No air bronchogram sign was observed.

Electrophysiological Characteristics of Classes of Neuron in the HVc of the Zebra Finch

1998 ◽  
Vol 80 (2) ◽  
pp. 914-923 ◽  
Author(s):  
Michinori Kubota ◽  
Ikuo Taniguchi
Keyword(s):  
Action Potential ◽  
Zebra Finch ◽  
Action Potential Duration ◽  
The Other ◽  
Time Dependent ◽  
Inward Rectification ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv

Kubota, Michinori and Ikuo Taniguchi. Electrophysiological characteristics of classes of neuron in the HVc of the zebra finch. J. Neurophysiol. 80: 914–923, 1998. Whole cell recordings were made from zebra finch HVc neurons in slice preparations. Four distinct classes of neuron were found on the basis of their electrophysiological properties. The morphological characteristics of some of these neurons were also examined by intracellular injection of Lucifer yellow. Type I neurons (21 of 65 cells) had longer time-to-peak of an afterhyperpolarization following an action potential than the other classes. They exhibited both fast and time-dependent inward rectification and an initial high-frequency firing followed by a slower constant firing. Type I neurons had large somata and thick dendrites with many spines. The axons of some of the neurons in this class projected in the direction of area X of the parolfactory lobe. Type II neurons (30 of 65 cells) had a more negative resting membrane potential than the other classes. They exhibited fast inward rectification. Type II neurons could be divided into two subclasses by the absence (IIa; 22 cells) and the presence (IIb; 8 cells) of a low-threshold transient depolarization. Type IIa neurons had relatively small somata and thin, spiny dendrites. The axons of some of the neurons in this class projected in the direction of the robust nucleus of the archistriatum (RA). Type IIb neurons had relatively large somata and thick dendrites with many spines. Type III neurons (6 of 65 cells) had a shorter action-potential duration than the other classes. They exhibited prominent time-dependent inward rectification and a regular tonic firing with little or no accommodation. Type III neurons had beaded, aspiny dendrites. Type IV neurons (8 of 65 cells) had a longer action-potential duration, a much larger input resistance, and longer membrane time constant than the other classes. Type IV neurons had small somata and thin, short, sparsely spiny dendrites. The axons of some of the neurons in this class projected in the direction of the RA. These classes of neuron may play distinct roles in song production and representation in the HVc.

Threading Dislocation Behavior in InGaAs/GaAs (001) Superlattice Buffer Layers

2019 ◽  
Vol 28 (03n04) ◽  
pp. 1940017
Author(s):  
Md Tanvirul Islam ◽  
Tedi Kujofsa ◽  
Xinkang Chen ◽  
J. E. Ayers
Keyword(s):  
Layer Thickness ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Indium Composition ◽  
Type Iv ◽  
Modulation Type ◽  
Dislocation Behavior

We conducted a modeling study of the threading dislocation behavior in chirped and unchirped InGaAs/GaAs (001) strained-layer superlattices (SLSs) using a Dodson & Tsao / Kujofsa & Ayers (DTKA) type plastic flow model. Four types of SLSs were investigated: type I was chirped using compositional modulation, type II was chirped using layer thickness modulation, type III was unchirped with alternating layers of InGaAs and GaAs, and type IV was unchirped with alternating layers of InGaAs having two different compositions. Generally the surface and average values of the dislocation density decreased with increasing total thickness. The dependence on top indium composition was more complex, due to dislocation compensation and multiplication effects, but for type II and IV superlattices, the average and surface threading dislocation densities increased in nearly monotonic fashion with top indium composition. Based on these results, the compositionally-modulated chirped (type I) and InGaAs/GaAs unchirped (type III) superlattices appear to be best suited as buffer layers for metamorphic devices, while the chirped superlattices with layer thickness modulation (type II) and InGaAs/InGaAs unchirped (type IV) superlattices appear to be poorly suited for use as buffer layers for devices containing high indium content.

Syntheses of Post-Iboga Alkaloids

Synthesis ◽  
2019 ◽  
Vol 51 (14) ◽  
pp. 2737-2758 ◽  
Author(s):  
Hyeonggeun Lim ◽  
Sikwang Seong ◽  
Sunkyu Han
Keyword(s):  
Secondary Metabolites ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Synthetic Studies ◽  
Type V

Post-iboga alkaloids are secondary metabolites that are biosynthetically derived from iboga-type alkaloids via rearrangements of the indole and/or isoquinuclidine moieties. Herein, we categorize post-iboga alkaloids into five types based on the biosynthetic mode of transformation of the iboga scaffold. We then describe reported syntheses of post-iboga alkaloids, including our laboratory’s recent contributions, based on our own categorization.1 Introduction1.1 Iboga and Post-Iboga Alkaloids1.2 Classification of Post-Iboga Alkaloids1.2.1 Introduction to Type I Post-Iboga Alkaloids1.2.2 Introduction to Type II Post-Iboga Alkaloids1.2.3 Introduction to Type III Post-Iboga Alkaloids1.2.4 Introduction to Type IV Post-Iboga Alkaloids1.2.5 Introduction to Type V Post-Iboga Alkaloids2 Syntheses of Post-Iboga Alkaloids2.1 Syntheses of Type I Post-Iboga Alkaloids2.1.1 Syntheses of Monomeric Type I Post-Iboga Alkaloids2.1.2 Syntheses of Dimeric Type I Post-Iboga Alkaloids2.2 Syntheses of Type II Post-Iboga Alkaloids2.3 Synthetic Studies Toward Type III Post-Iboga Alkaloids2.4 Syntheses of Type IV Post-Iboga Alkaloids2.5 Synthesis of Type V Post-Iboga Alkaloids3 Conclusion and Outlook

Sign in / Sign up

Export Citation Format

Share Document