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PubMed1990

Polypeptide composition and organization of the sea urchin extraembryonic hyaline layer.

The protein composition and organization of the sea urchin extraembryonic hyaline layer was examined. Hyalin and a polypeptide of 45 kilodaltons (kDa) were present in hyaline layers isolated from 1-h-old embryos through to the pluteus larva stage. In contrast, several polypeptide species ranging in size from 175 to 32 kDa either decreased in amount or disappeared from the layer as embryonic development proceeded. Concomitant with the changes in composition, hyaline layers became progressively more refractory to dissolution by washing in Ca2+, Mg2(+)-free seawater. Incubation of intact layers, isolated from 1-h-old embryos, with proteinase K resulted in the selective digestion of hyalin and was accompanied by release of the 45-kDa polypeptide from the layers. Washing intact layers in 20 mM Tris (pH 8.0) also resulted in the selective removal of hyalin and the 45-kDa polypeptide. The Ca2(+)-precipitable protein hyalin, alone among the hyaline layer polypeptides, bound the Ca2(+)-antagonist ruthenium red. These results suggest a structural organization within the hyaline layer that is both heterogenous and dynamic throughout embryonic development.

Animals↗
PubMed2000

Three layers of the medial capsular and supporting structures of the knee: MR imaging-anatomic correlation.

The authors used a three-layer approach to correlate the appearance of the capsule and ligaments of the medial side of the knee on magnetic resonance (MR) images with corresponding anatomic slices. MR images of six fresh cadaveric specimens were obtained by using a proton-density-weighted fast spin-echo sequence with a 256 x 512 matrix. Specimens were frozen and sliced with a band saw into 3. 0-mm-thick sections that corresponded to the MR images. Three layers were depicted on both anatomic slices and MR images. Layer 1 consisted of the deep crural fascia; layer 2, the superficial portion of the medial collateral ligament (MCL); and layer 3, the capsule, the deep portion of the MCL, the meniscofemoral and meniscotibial extensions of the deep portion of the MCL, and the patellomeniscal ligament. Along the anterior aspect of the medial side of the knee, layer 1 was fused with layer 2; along the posterior aspect of the knee, layer 2 was fused with layer 3.

Aged↗
PubMed2004

Layer variations of long-term depression in rat visual cortex.

In vitro long-term depression (LTD) is thought to be a model for the loss of cortical responsiveness to an eye deprived of vision during the critical period. Using whole cell recording, the present study investigates the mechanisms of LTD in vitro across layers in developing rat visual cortex. LTD was induced in layers II/III, V, and VI but not layer IV with 10-min 1-Hz stimulation paired with postsynaptic depolarization. LTD in layers II/III and V could be blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist D-aminophosphonovaleric acid (D-AP5) but not by 100 microM (2S)-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl) propanoic acid (LY341495), a metabotropic glutamate receptor inhibitor. In contrast, LTD in layer VI was blocked by 100 microM LY341495 and (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA) but not D-AP5 and partially blocked by application of guanosine 5'-O-(2-thiodiphosphate) thilothium salt (GDP-beta-S) in patch pipette, suggesting an involvement of postsynaptic group I metabotropic glutamate receptors (mGluRs). These results indicate that LTD in developing rat visual cortex varies with layer: LTD was absent in layer IV, suggesting a unique plasticity mechanism at geniculocortical synapses; LTD in layers II/III and V depends on NMDA receptors but not mGluRs, and LTD in layer VI requires mGluRs but not NMDA receptors.

Animals↗
PubMed1983

Activity of cells in area 17 of the cat in absence of input from layer a of lateral geniculate nucleus.

1. Injections of 4 mM cobaltous chloride were used to block synaptic transmission in layer A of the lateral geniculate nucleus (LGN) without blocking fibers of passage going to or arising from other layers. 2. Selective inactivation of geniculate layer A virtually abolished all visual activity in cortical layers 4ab, 4c, and 6. Under these conditions, the stimulus-evoked response, orientation selectivity, and direction selectivity of cells in layers 2 and 3 were not seriously affected. In layer 5, the effects of the block were more variable, with special complex cells least affected and simple cells most affected. 3. Since the organization of complex receptive fields and the maintenance of normal orientation selectivity in supragranular layers survive disruption of major interlaminar interactions, it appears that much of the functional architecture of cat striate cortex does not depend on the integrity of the column. 4. These results support the idea that each layer of the LGN is a functional unit with a unique pattern of access to the various layers of visual cortex.

Animals↗
PubMed1994

Origin of the apparent tissue conductivity in the molecular and granular layers of the in vitro turtle cerebellum and the interpretation of current source-density analysis.

1. We determined the origin of the apparent tissue conductivity (sigma 2) of the turtle cerebellum in vitro. 2. Application of a current with a known current density (J) along the longitudinal axis of a conductivity cell produced an electric field in the cerebellum suspended in the cell. The measured electric field (E) perpendicular to the cerebellar surface indicated a significant inhomogeneity in sigma a (= J/E) with a major discontinuity between the molecular layer (0.25 +/- 0.05 S/m, mean +/- SD) and granular layers (0.15 +/- 0.03 S/m) (n = 39). 3. This inhomogeneity was more pronounced after anoxic depolarization. The value of sigma a decreased to 0.11 +/- 0.03 and 0.040 +/- 0.008 S/m in the molecular and granular layers, respectively. The ratio of sigma a S in the two layers increased from 1.67 in the normoxic condition to 2.75 after anoxic depolarization. 4. This difference in sigma a across the two layers was present within the range of frequencies (DC to 10 kHz) studied where the phase of sigma a was small (less than +/- 2 degrees) and therefore sigma a was ohmic. 5. The inhomogeneity in sigma a was in part due to an inhomogeneity in the extracellular conductivity (sigma e) as determined from the extracellular diffusion of ionophoresed tetramethylammonium. Like sigma a, the value of sigma e was also higher in the molecular layer (0.165 S/m) than in the granular layer (0.097 S/m). The inhomogeneity in sigma e was due to a smaller tortuosity and a larger extracellular volume fraction in the molecular layer compared with the granular layer. 6. sigma a was, however, consistently higher, by approximately 50%, than sigma e. A core conductor model of the cerebellum indicated that these discrepancies between sigma a and sigma e were attributable to additional conductivity produced by a passage of the longitudinal applied current through the intracellular space of Purkinje cells and ependymal glial cells, with the glial compartment playing the dominant role. Cells with a long process and a short space constant such as the ependymal glia evidently enhance the effective "extracellular" conductivity by serving as intracellular conduits for the applied current. The result implies that the effective sigma e may be larger than sigma e for neuronally generated currents in the turtle cerebellum because the space constant for Purkinje cells is several times greater than that for the ependymal glia and consequently Purkinje cell-generated currents travel over a long distance relative to the space constant of glial cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1998

Effects of focal inactivation of dorsal or ventral layers of the lateral geniculate nucleus on cats' ability to see and fixate small targets.

To reveal contributions of different subdivisions of the lateral geniculate nucleus (LGN) to visuomotor behavior, segments of either layer A or the C layers were inactivated with microinjections of gamma-aminobutyric acid while cats made saccades to retinally stabilized spots of light placed either in affected regions of visual space or mirror-symmetric locations in the opposite hemifield. Inactivating layer A reduced the success rate for saccades to targets presented in affected locations from 82.4 to 26.8% while having no effect on saccades to the control hemifield. Saccades to affected sites had reduced accuracy and longer initiation latency and tended to be hypometric. In contrast, inactivating C layers did not affect performance. Data from all conditions fell along the same saccade velocity/amplitude function ("main sequence"), suggesting that LGN inactivations cause localization deficits, but do not interfere with saccade dynamics. Cerebral cortex is the only target of the A layers, so behavioral decrements caused by inactivating layer A must be related to changes in cortical activity. Inactivating layer A substantially reduces the activity of large subsets of corticotectal cells in areas 17 and 18, whereas few corticotectal cells depend on C layers for visually driven activity. The parallels between these behavioral and electrophysiological data along with the central role of the superior colliculus in saccadic eye movements suggests that the corticotectal pathway is involved in both deficits and remaining capacities resulting from blockade of layer A.

Animals↗
PubMed1983

Regional distributions of choline acetyltransferase and acetylcholinesterase activities in layers of rat cerebellar vermis.

Entire sagittal sections of rat cerebellar vermis were dissected into microgram-sized samples of molecular, granular, and white matter layers. Assayed activities of choline acetyltransferase and acetylcholinesterase were plotted back onto sectional maps of exact sample locations. On the average, the activities of choline acetyltransferase and acetylcholinesterase in the granular layer were about four and five times, respectively, those in the molecular layer. The highest activity of both enzymes was in the granular layer of the vestibulocerebellum, the nodulus and ventral uvula (lobules X and IXc of Larsell). This activity might be related to the secondary vestibulocerebellar projection, terminating as mossy fibers in the granular layer of this region. Intermediate levels of activity were found in the granular layer of the dorsal uvula (lobule IX, a and b). The lowest activities of both enzymes in the granular layer were in the culmen (lobule V). A 7.1-fold difference in choline acetyltransferase activity and a 4.5-fold difference in acetylcholinesterase activity were found between the granular layer of lobules V and X. The numerical density of aggregates of acetylcholinesterase staining product in the granular layer correlated much better with assayed acetylcholinesterase activity than with choline acetyltransferase activity.

Acetylcholinesterase↗
PubMed2002

Double-layered mucoadhesive tablets containing nystatin.

The objective of this work was to design a mucoadhesive tablet with a potential use in the treatment of oral candidosis. A 2-layered tablet containing nystatin was formulated. Lactose CD (direct compression), carbomer (CB), and hydroxypropylmethylcellulose (HPMC) were used as excipients. Tablets were obtained through direct compression. Properties such as in vitro mucoadhesion, water uptake, front movements, and drug release were evaluated. The immediate release layer was made of lactose CD (100 mg) and nystatin (30 mg). The CB:HPMC 9:1 mixture showed the best mucoadhesion properties and was selected as excipient for the mucoadhesive polymeric layer (200 mg). The incorporation of nystatin (33.3 mg) in this layer affected the water uptake, which, in turn, modified the erosion front behavior. Nystatin showed a first-order release. The polymeric layer presented an anomalous kinetic (n = 0.82) when this layer was individually evaluated. The mucoadhesive tablet formulated in this work releases nystatin quickly from the lactose layer and then in a sustained way, during approximately 6 hours, from the polymeric layer. The mixture CB:HPMC 9:1 showed good in vitro mucoadhesion. A swelling-diffusion process modulates the release of nystatin from this layer. A non-Fickian (anomalous) kinetic was observed.

Acrylic Resins↗
PubMed1997

Induction of deep layer cortical neurons in vitro.

Transplantation studies suggest that the laminar fates of cerebral cortical neurons are determined by environmental signals encountered just before mitosis. In ferret, E29 progenitor cells normally produce neurons of layers 5 and 6. When transplanted during S-phase into an older ventricular zone, E29 progenitors produce neurons that change their fates and migrate to layer 2/3; however, cells transplanted later in the cell cycle migrate to their normal deep-layer positions even in an older environment (McConnell and Kaznowski, 1991). Here we utilize three culture systems to investigate the nature of the environmental signals involved in laminar specification. E29 cells were first cultured at low density to ascertain whether cell contact and/or short-range cues are required for deep layer specification. Neurons transplanted after a short time in low-density culture failed to adopt their normal fates and migrated instead to the upper layers. When crude cell contacts were restored by pelleting E29 cells together, most transplanted neurons cells became specified to their normal deep layer fates. Finally, E29 cells were transplanted after being cultured in explants that maintained the architecture of the cerebral wall. Explants allowed normal deep layer specification to occur, as transplanted cells migrated to layers 5 and 6. These results suggest that short-range cues induce multipotent progenitors to produce deep layer neurons.

Animals↗
PubMed2002

Release from or through a wax matrix system. III. Basic properties of release through the wax matrix layer.

Release property of reservoir device matrix tablet was examined. Wax matrix layer was prepared from physical mixture of lactose and hydrogenated castor oil to obtain basic release properties. Release process showed zero order kinetics in a steady state after a given lag times, and could be divided into two stages. The first stage was the formation process of water channel by dissolving the soluble component in the wax matrix layer. The lag time was considered to be the time required forming water channel and the time begun to release drug through the wax matrix layer at the same time. The lag time obtained by applying the square root law equation was well connected with the amount of matrix layer and mixed weight fraction of component in matrix layer. The second stage was the zero order release process of drug in the reservoir through the wax matrix layer. The release rate constants were calculated by taking into accounts of the thickness of matrix layer and permeability coefficient, and were well connected with the amount of matrix layer and mixed weight fraction of component. Also it was suggested that the tortuosity of matrix layer could be expressed by a function of the porosity defined by the mixed weight fraction.

Chemistry, Pharmaceutical↗
PubMed2005

Dual layer and multilayer enhancements from silver film over nanostructured surface-enhanced Raman substrates.

Novel dual layer and multilayer silver film over nanostructure (SFON) substrates have been developed that provide surface-enhanced Raman scattering (SERS) signal enhancements of greater than 1000% compared to conventional single layer SFON substrates. These substrates provide signal enhancement factors of 3.8 x 10(5) and greater for a variety of SERS active analytes. Substrate preparation is accomplished by vapor depositing a thick (approximately 100 nm) layer of silver on top of an underlying layer of alumina nanoparticles, followed by deposition of additional layers of silver with silver oxide layers between them. Unlike previous dual layer silver island based substrates that have been developed, these substrates do not rely on achieving an optimal morphology via deposition of silver. Instead, these substrates rely on the roughness being provided by the original under-layer, providing enhanced substrate homogeneity and more reproducible signals than either silver island substrates or colloidal substrates. In addition, the signal enhancement gives these substrates extended lifetimes compared to conventional single layer SFON substrates. Finally, this study also shows that geometric surface structure and surface roughness factors play little or no role in this enhancement process, allowing for this multilayer fabrication process to be applied to many different types of substrates achieving similar or even greater results.

Benzoic Acid↗
PubMed2001

Characterization of the laminated layer of in vitro cultivated Echinococcus vogeli metacestodes.

The metacestode (larval) stages of the cestode parasites Echinococcus vogeli and E. multilocularis were isolated from the peritoneal cavity of experimentally infected C57BL/6 mice and were cultured in vitro for a period of up to 4 mo under conditions normally applied for the in vitro cultivation of E. multilocularis metacestodes. In contrast to E. multilocularis, E. vogeli did not exhibit extensive exogenous budding and proliferation but increased in size with a final diameter of up to 10 mm. Most metacestodes contained protoscoleces, singly or in groups, either associated with brood capsules or growing directly out of the germinal layer. Each individual metacestode was covered by an acellular translucent laminated layer that was considerably thicker than the laminated layer of E. multilocularis metacestodes. The ultrastructural characteristics, protein content, and carbohydrate composition of the laminated layer of in vitro cultivated E. vogeli and E. multilocularis were assessed using transmission electron microscopy, lectin fluorescence labeling, and lectin blotting assays. The laminated layer of E. vogeli is, as previously described for E. multilocularis metacestodes, largely composed of N-acetyl-beta-D-galactosaminyl residues and alpha- and beta-D-galactosyl residues, as well as of the core structure of O-linked carbohydrate chains, N-acetylgalactosamine-beta-1,3-galactose. However, in contrast to E. multilocularis, N-linked glycopeptides and alpha-D-mannosyl and/or glucosyl residues were also associated with the laminated layer of E. vogeli. The laminated layer from both species was isolated from in vitro cultivated metacestodes, and the purified fractions were comparatively analyzed. The protein:carbohydrate ratio (1:1) was similar in both parasites; however, the protein banding pattern obtained by silver staining following sodium dodecyl sulfate polyacrylamide gel electrophoresis suggested intrinsic differences in protein composition. A polyclonal antiserum raised against the E. multilocularis laminated layer and a monoclonal antibody, G11, directed against the major E. multilocularis laminated layer antigen Em2 did not cross-react with E. vogeli, indicating distinct compositional and antigenic differences between these 2 parasites.

Animals↗
PubMed2005

The effect of flow path and mixing layer on phosphorus release: physical mechanisms and temperature effects.

Soil phosphorus (P) concentrations typically are greater in surface soils compared with subsurface soils. Surface soils have a greater chance to interact with runoff leading to P transport to streams. The thin surface layer where P concentrates is referred to as the mixing layer denoting where water and chemicals mix during transport. The objective of this study was to evaluate the effect of hydrologic flow paths on soluble reactive phosphorus (SRP) loss at two temperatures. Laboratory flumes were built to simulate infiltration, return flow, saturation excess, and interflow, and subsequent interaction with the mixing layer. The sandy loam soil in the flumes was kept at saturation throughout all experiments, so that biochemical effects were normalized. Flow through the flumes was maintained at 3.6 mm/h for 24 to 99 h (at 6 and 25 degrees C) with water entering and exiting the flumes at different ports (to simulate different flow paths) or as low intensity rainfall. Experiments were performed with and without an artificially created P-enriched surface layer (5 mm thick, total P increased from 1010 mg/kg in the original soil to 2310 mg/kg by addition of dissolved phosphate). Results indicated that (i) SRP release was greater in soil with a mixing layer than in soil without a mixing layer; (ii) SRP release was greater during experiments at 25 degrees C than at 6 degrees C; (iii) at 25 degrees C, SRP release was greatest when water traversed the mixing layer in the upward direction (i.e., in return flow), and by flow parallel to the mixing layer (i.e., surface runoff); and (iv) at 6 degrees C, SRP release in subsurface flow following rainfall was slightly greater than in return flow and infiltration. Our results confirmed the presence of a variable, temperature-dependent desorption process when runoff water interacted with the mixing layer. Our findings have important implications for how different water flow paths in and over the soil interact with P in the soil, and what the ultimate concentration will be in runoff and interflow.

Hydrogen-Ion Concentration↗
PubMed1994

Phytase activity, phosphorus and calcium retention, and performance of single comb White Leghorn layers fed diets containing two levels of available phosphorus and supplemented with direct-fed microbials.

The presence of phytase activities in condensed cane molasses solubles (CCMS) and CCMS-Lactobacillus (Lacto) were determined. Single Comb White Leghorn layers were fed .25 and .45% available P (AP) diets supplemented with CCMS and CCMS-Lacto for nine 28-d periods to determine phytase activities of the gastrointestinal (GI) tract contents and intestine, liver, and pancreatic tissues, the GI tract pH, the P and Ca retention, and layer performance. Six dietary treatments were corn-soybean (C-S) control, C-S+CCMS, and C-S+CCMS-1,100 mg Lacto/kg diet (ppm) [4.4 x 10(7) cfu/mg Lacto] each with .25 and .45% AP. The CCMS were used as a carrier for the Lacto, and the CCMS and CCMS-Lacto premix were incorporated at 2% of the diets. Phytase activity was much higher in CCMS-Lacto premix than in CCMS. Phytase activities of the crop contents were higher with the CCMS-Lacto diets regardless of the AP level. Intestinal phytase activity was higher with the .45% AP CCMS-Lacto diet than the unsupplemented .45% AP diets. Lactobacillus supplementation did not stimulate phytase activities in the intestinal contents or liver and pancreatic tissues. The pH of the crop and intestinal contents were much lower for the Lacto-fed layers than the layers fed unsupplemented diets regardless of dietary AP levels. No differences in Ca retentions were observed with Lacto supplementation regardless of the dietary AP levels. However, higher P retentions were observed with the Lacto supplementation in the .25% AP diet. Layers fed .25 and .45% AP Lacto-supplemented diets had lower hen-day egg production, poorer feed conversion value, consumed slightly more feed, produced less egg mass, and laid larger eggs than the layers fed .25 and .45% AP unsupplemented diets. Lacto supplementation to .25% AP diet produced eggs with higher specific gravity than the unsupplemented .45% AP diet, but not different from unsupplemented .25% AP diet. Layers fed the .25% AP diets had lower BW gains then layers fed the .45% AP diets regardless of lacto supplementation. Phytase activity was present in the lacto source, and the presence of phytase and Lacto supplementation to a .25% AP diet improved P retention in layers.

6-Phytase↗
PubMed1999

Repopulation of different layers of host human Bruch's membrane by retinal pigment epithelial cell grafts.

PURPOSE: To determine the morphology of human retinal pigment epithelium (RPE) after reattachment to different ultrastructural layers of human Bruch's membrane (BM). METHODS: Bruch's membrane explants were prepared from eyes of 23 human donors (age range, 11-89 years). The basal lamina of the RPE, inner collagenous layer, and elastin layer were removed sequentially by mechanical and enzymatic techniques. First-passage cells of human RPE (15,000 cells/6 mm explant) from three donors (ages, 52, 64, and 80 years) were plated onto different layers of human BM, and the explants were examined by scanning and transmission electron microscopy up to 21 days later. RESULTS: RPE flattened and extended footplates 6 hours after plating onto basal lamina. Cells remained round 6 and 24 hours after plating onto the inner collagenous, elastin, or outer collagenous layer. The RPE cells became confluent 14 days after plating onto basal lamina but did not become confluent up to 21 days after plating onto the inner collagenous or elastin layer. Sparse round cells were observed 21 days after plating onto deeper layers, suggesting extensive loss of RPE. CONCLUSIONS: The morphology and subsequent behavior of the RPE reattached to BM depends on the anatomic layer of BM available for cell reattachment. The results suggest that the ability of transplanted RPE to repopulate BM in age-related macular degeneration and other disorders may depend on the layer of BM available to serve as a substrate for cell reattachment.

Adolescent↗
PubMed2000

Abnormalities of adherent layers grown from bone marrow of patients with myelodysplasia.

Myelodysplastic syndromes (MDS) are characterized by a clonal disorder of haemopoiesis with defective growth in vitro. The long-term culture system was used to examine aspects of stromal function in MDS patients. Primary long-term cultures of MDS bone marrow showed poor myelopoiesis with progenitors being detected for a median 3.5 weeks (n = 12) compared with 18 weeks in cultures of normal marrow (n = 10; P < 0.0001). The haemopoietic function of adherent layers was assessed in secondary co-cultures seeded with 5 x 10(6) cord blood mononuclear cells on irradiated normal (n = 27; aged 38-82 years) or MDS (n = 32; aged 41-86 years) adherent layers (> 60% confluent). The median myeloid progenitor number/cord blood co-culture was 135 in 5-week-old cultures with normal adherent layers and 22 in those with MDS layers (P < 0.0001). Myeloid colonies were detectable for a median 11 weeks with normal adherent layers and 6 weeks with MDS adherent layers (P < 0.0001); erythroid colonies were detectable for 7 weeks (normal) compared with 5 weeks (MDS) (P < 0.01). The differences in granulocyte-macrophage colony forming unit (CFU-GM) generation were not related to patient age. Cells from adherent layers of at least half of the primary normal (n = 48) and MDS (n = 26) long-term cultures expressed cytokines [interleukin (IL)-3, IL-1 beta, thrombopoietin (Tpo) and erythropoietin (Epo)] and receptors for retinoic acid (RAR alpha) [IL-2, IL-3, macrophage colony stimulating factor (M-CSF) (Fms) and Tpo (Mpl)]. Only IL-1 beta expression was reduced in week-5 MDS cultures compared with those from normal marrows (P < 0.05). There was also a highly significant decline in IL-1 beta expression in normal (but not MDS) adherent layers between week 5 and week 10. Thus, the adherent layers in cultures grown from MDS patients were haemopoietically defective and showed abnormal IL-1 beta expression.

Adult↗
PubMed2002

Variation in effective stimulus patterns for induction of long-term potentiation across different layers of rat entorhinal cortex.

Neuronal activities in superficial (II and III) and deep (V and VI) layers of the entorhinal cortex (EC) are preferentially modulated by theta and sharp wave (SPW) EEG, respectively. We investigated the possibility that distinct EEG patterns represent optimal stimulus patterns for induction of long-term potentiation (LTP) in different layers of the EC. We examined effects of three different stimulation patterns on LTP induction in layers I, II-III, and V of medial EC slices of the rat. The stimulation patterns we used were a single, long high-frequency train (1 sec at 100 Hz, repeated 3x), theta burst stimulation [TBS; 10 bursts (four pulses, 100 Hz) at 5 Hz, repeated 3x], and SPW-like burst stimulation [ SPWBS; three bursts (20 pulses, 200 Hz) at 2 Hz, repeated 6x]. Similar degrees of LTP were induced by the three stimulation patterns in layer I. In layers II--III and layer V, however, the largest degrees of LTP were induced by TBS and SPWBS, respectively. These results suggest that burst stimulation constructed to mimic naturally occurring patterns of neuronal activity in the corresponding layer is optimal for LTP induction in layers II-III and layer V of the EC. The differences may play important roles in shaping hippocampal-neocortical interactions in encoding and retrieval of memory.

Analysis of Variance↗
PubMed1992

[Morphological characteristics of tissue components of various layers of the rat myocardium in the early period of development of myocardial hypertrophy].

The tissue components of the subendocardial, intramural and subepicardial layers of the myocardium of rats were examined by morphometry on the 10 day after 50% subphrenic coarctation of the abdominal aorta. The decrease of the relative volume of cardiomyocytes in the subendocardial layer and the increase of this index in the other layers of myocardium were discovered. The decrease of the surface of cardiomyocytes was maximal in the intramural layer and in the other examined layers the decrease was less. Some increase of the average diameters of cardiomyocytes in subepicardial and intramural layers was shown. The cardiomyocytes diameter practically did not change in the subendocardial layer. The increase of the relative volume and surface of the capillaries was revealed in the subendocardial layer. These indexes were decreased in a different degree in the subepicardial and intramural layers.

Animals↗