Interneuronal Projections to Identified Cilia-Activating Pedal Neurons in Hermissenda

2003 ◽  
Vol 89 (5) ◽  
pp. 2420-2429 ◽  
Author(s):  
Terry Crow ◽  
Lian-Ming Tian
Keyword(s):  
Synaptic Input ◽  
Visual Processing ◽  
Inhibitory Interneuron ◽  
Type I ◽  
Type Ii ◽  
Synaptic Organization ◽  
Ciliary Movement ◽  
The Neural Network ◽  
Excitatory Synaptic Input

Neural networks have been shown to support the generation of more than one behavioral motor act. In the nudibranch mollusk Hermissenda, Pavlovian conditioning results in light, the conditioned stimulus (CS), evoking both inhibition of locomotion and foot contraction. The synaptic organization of the eyes and optic ganglion is well documented; however, the characterization of the neural network mediating visually modulated behaviors is incomplete. We have now characterized synaptic connections between identified photoreceptors and a newly identified interneuron (IIb), identified synaptic projections from type I and type II interneurons to an inhibitory interneuron (IIIi) and to two newly identified pedal neurons, VP1 and VP2. Here we show that VP1 activates ciliary movement on the anterior foot and VP2 innervates the anterior foot and ventral tentacle. Stimulation of the photoreceptors with light produced two effects on the activity of VP1 and VP2. First, light inhibits type Ii and IIi interneurons and disinhibits VP1 and VP2. Depolarization of type IIe interneurons also disinhibits VP1 and VP2. Second, the light-elicited depolarization and increased tonic activity of VP1 and VP2 is produced by excitatory synaptic input from ipsilateral and contralateral type IIbinterneurons. Pedal neurons VP1 and VP2 receive similar synaptic input from type I, II, and IIIi interneurons; this is in agreement with previous research showing that the visual pathway influences both ciliary locomotion and foot movement. The organization of the visual system in Hermissenda provides for the expression of cellular and synaptic plasticity supporting learning without altering the networks ability to carry out the requirements for normal visual processing.

Cellular studies of peripheral neurons in siphon skin of Aplysia californica

1979 ◽  
Vol 42 (2) ◽  
pp. 530-557 ◽  
Author(s):  
C. H. Bailey ◽  
V. F. Castellucci ◽  
J. Koester ◽  
E. R. Kandel
Keyword(s):  
Motor Neurons ◽  
Synaptic Input ◽  
Firing Pattern ◽  
White Cell ◽  
Type I ◽  
Type Ii ◽  
Peripheral Neurons ◽  
Peripheral Neuron ◽  
Type I Neuron ◽  
Kinetics Of

1. To account for the similarity in the kinetics of habituation between the central and peripheral components of siphon withdrawal, we have tested the idea (52) that each centrally located mechanoreceptor sensory neuron sends two branches to siphon motor neurons; one to centrally located siphon motor neurons and a collateral branch that remains in the periphery and innervates the peripheral siphon motor neurons. 2. We have found a group of peripheral siphon motor neurons and tested the connection onto these cells by central mechanoreceptors. In addition, we have defined by various electrophysiological and morphological criteria two general classes of peripheral neurons that lie along the course of the siphon nerve. 3. One class (type I) consists of only a single cell in each animal. This peripheral neuron typically has the largest cell body found lying along the siphon nerve and is the only peripheral nerve cell that appears white when viewed under epi-illumination. The type I neuron often has a highly regular firing pattern, which occurs in the absence of spontaneous synaptic input. The three-dimensional morphology of this neuron suggests a paucity of fine processes, most of which do not arborize and may terminate in the connective tissue sheath. Fine structural observations of the peripheral white cell have revealed the presence of large densecore granules. The peripheral type I neuron is similar in most of its electrophysiological and morphological properties to central neurons postulated to be neurosecretory. The peripheral white cell is, at present, the only peripheral neuron we can identify with certainty as a unique individual. 4. The second class (type II) of peripheral neurons are siphon motor neurons for the peripheral component of the siphon-withdrawal reflex. In contrast to the type I neurons, members of the second class of peripheral neurons possess smaller, more spherical cell bodies that have varying amounts of orange pigmentation and which give rise to a relatively well-developed and arborized dendritic tree. Type II neurons feature an irregular spontaneous firing pattern that is occasionally modulated by a rich spontaneous synaptic input. Peripheral siphon motor neurons have restricted motor fields that produce contraction of the mantle floor and the base of the siphon. Most of the type II neurons were found to be electrically coupled to one another. 5. The peripheral siphon motor neurons resemble the central siphon motor neurons in that they receive a collateral synapse from centrally located mechanoreceptor sensory neurons. This peripheral sensory-to-motor synapse exhibits the same kinetics of decrement as its central counterpart, both of which parallel behavioral habituation. 6. The rich mechanoreceptor input onto the relatively isolated dendritic trees of the peripheral siphon motor neurons provide a uniquely restricted neuropil to study the sensory-to-motor synapse. The peripheral motor neurons may, therefore, be a useful simple preparation for the cellular study of behavioral plasticity.

Evaluation of an enzyme immunoassay kit for estrogen receptor measurement--report II.

1988 ◽  
Vol 34 (10) ◽  
pp. 2053-2057 ◽  
Author(s):  
S Raam ◽  
D M Vrabel
Keyword(s):  
Enzyme Immunoassay ◽  
Binding Sites ◽  
Solid Phase ◽  
Functional Characterization ◽  
Quantitative Agreement ◽  
Type I ◽  
Type Ii ◽  
Immunoreactive Protein ◽  
Estrogen Binding

Abstract We present evidence to show that monoclonal antibodies to estrogen receptors (ER) in solid phase recognize the secondary estrogen binding sites with moderate to low affinity for estradiol (E2). An excellent quantitative agreement was found in five cytosols between the ER values obtained by the enzyme immunoassay (ER-EIA) and the amount of secondary estrogen binding sites measured by the assay involving dextran-coated charcoal (Clin Chem 1986;32:1496). The immunoreactive protein recognized by the antibody-coated beads, when allowed to react with ER(+) cytosols, is shown to bind [3H]estradiol only when the ligand concentration exceeds 8 nmol/L. Further biochemical and functional characterization of the immunoreactive protein is required to establish similarities/dissimilarities between this protein, high-affinity Type I ER sites, and the secondary sites such as Type II sites.

Geochemical characterization of hydrocarbon source rocks of the Triassic-Jurassic time interval in the Mandawa basin, southern Tanzania: Implications for petroleum generation potential

2020 ◽  
Vol 123 (4) ◽  
pp. 587-596
Author(s):  
A. Emanuel ◽  
C.H. Kasanzu ◽  
M. Kagya
Keyword(s):  
Source Rocks ◽  
Geochemical Data ◽  
Time Interval ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Geochemical Characterization ◽  
Type Iii ◽  
Petroleum Generation

Abstract Triassic to mid-Jurassic core samples of the Mandawa basin, southern Tanzania (western coast of the Indian Ocean), were geochemically analyzed in order to constrain source rock potentials and petroleum generation prospects of different stratigraphic formations within the coastal basin complex. The samples were collected from the Mihambia, Mbuo and Nondwa Formations in the basin. Geochemical characterization of source rocks intersected in exploration wells drilled between 503 to 4042 m below surface yielded highly variable organic matter contents (TOC) rated between fair and very good potential source rocks (0.5 to 8.7 wt%; mean ca. 2.3 wt%). Based on bulk geochemical data obtained in this study, the Mandawa source rocks are mainly Type I, Type II, Type III, mixed Types II/III and Type IV kerogens, with a predominance of Type II, Type III and mixed Type II/III. Based on pyrolysis data (Tmax 417 to 473oC; PI = 0.02 to 0.47; highly variable HI = 13 to 1 000 mg/gTOC; OI = 16 to 225 mg/g; and VR values of between 0.24 to 0.95% Ro) we suggest that the Triassic Mbuo Formation and possibly the mid-Jurassic Mihambia Formation have a higher potential for hydrocarbon generation than the Nondwa Formation as they are relatively thermally mature.

scholarly journals Characterization of two types of azedinha in the region of Sete Lagoas, Brazil

2013 ◽  
Vol 31 (2) ◽  
pp. 328-331 ◽  
Author(s):  
Ernani C da Silva ◽  
Lanamar de A Carlos ◽  
Ana Paula Araújo ◽  
Leila de CL Ferraz ◽  
Marinalva W Pedrosa ◽  
...  
Keyword(s):  
Transverse Diameter ◽  
Type I ◽  
Type Ii ◽  
Vegetable Crop ◽  
Rumex Acetosa ◽  
Crop Species ◽  
Minas Gerais State ◽  
Length Width ◽  
Longitudinal Diameter

Azedinha (Rumex acetosa) is a vegetable crop species consumed in natura in salads and pertains to the group of non-conventional vegetables. These rustic plants are often considered weeds plants. There exist two types of native azedinha in the Sete Lagoas region, Minas Gerais state, Brazil, that are usually grown in family gardens and here denominated Type I and Type II. In this study we characterized the morphologic, physic-chemical and chromatic characteristic of these two types of azedinha. The study was carried out in randomized complete blocks with four replications in dependences of the EPAMIG (Non-Conventional Vegetable Bank) in Prudente de Morais, Brazil. Plants were trained to the point of harvest, 90 days after the planting of seedlings, when they were harvested for analysis. We evaluated the characteristics on the leaves: weight, length, width, number of veins, width/length ratio, transverse and longitudinal diameter of the base of the petiole and longitudinal and transverse diameter ratio of the base of the petiole. We also evaluated the contents of macro and micronutrients and chemical characteristics of the plant. There are significant differences between the assessed characteristics between azedinha types I and II. We concluded that the plants probably belong to two different varieties.

scholarly journals Isolation and molecular characterization of type I and type II feline coronavirus in Malaysia

2012 ◽  
Vol 9 (1) ◽  
pp. 278 ◽  
Author(s):  
Amer Alazawy ◽  
Siti Suri Arshad ◽  
Abdul Rahman Omar ◽  
Mohd Hair Bejo ◽  
Faruku Bande ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Type I ◽  
Type Ii ◽  
Feline Coronavirus

Identification and characterization of 20 novel pathogenic variants in 60 unrelated Indian patients with mucopolysaccharidoses type I and type II

2016 ◽  
Vol 90 (6) ◽  
pp. 496-508 ◽  
Author(s):  
A. Uttarilli ◽  
P. Ranganath ◽  
D. Matta ◽  
J. Md Nurul Jain ◽  
K. Prasad ◽  
...  
Keyword(s):  
Type I ◽  
Type Ii ◽  
Pathogenic Variants ◽  
Indian Patients ◽  
Identification And Characterization

EBSD-Based Crystallographic Study on a Ni-Mn-Ga Alloy with Incommensurate 7M Structure

2011 ◽  
Vol 702-703 ◽  
pp. 530-535
Author(s):  
Zong Bin Li ◽  
Yu Dong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
Liang Zuo
Keyword(s):  
Martensite Transformation ◽  
Type I ◽  
Type Ii ◽  
Orientation Relationships ◽  
Twin Interface ◽  
Crystallographic Study ◽  
Austenite Grains ◽  
Parent Austenite ◽  
Martensitic Variants

Our recent work on EBSD-based characterization of incommensurate 7M modulated martensite in a polycrystalline Ni50Mn30Ga20alloy were summarized. The 7M martensitic plates were revealed to be self-accommodated in colonies, where each colony consisted of four types of variants that were twin related. All the pairs of variants can be categorized into three twinning modes, i.e. type-I, type-II and compound twins. The twin interface planes were in coincidence with the respective twinning planes. Using the measured orientations of adjacent martensitic variants, the orientations of parent austenite grains were calculated under the assumed orientation relationships for the austenite to martensite transformation. The energetically favorable orientation relationship between austenite and martenstie for the martensitic transformation was identified to be the Pitsch relation.

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