Vertical distribution of Microcystis population in the regulated Nakdong River, Korea

The vertical distribution of a bloom-forming Microcystis population was studied based on the relevant limnological parameters obtained from the lower Nakdong River (Mulgum) during the summer of 1994. Over three months (late June to late September), a high abundance of Microcystis population (mean ± SD, 2.9 ± 8.4 × 10⁵ cells ml⁻¹, n = 40) and algal biomass (mean ± SD, chlorophyll a, 131 ± 346 μg l⁻¹, n = 31) was persistent throughout the entire water column (0–5 m, n = 11). The vertical distribution of carbon content was uneven, with a high concentration near the surface zone (mean ± SD, total, 7.9 ± 7.8; Microcystis, 5.2 ± 8.3 μg C ml⁻¹, n = 15). Incorporating limnological and meteorological factors, a diel study of the vertical distribution of Microcystis showed that the chlorophyll a concentration was highest near the surface zone on a calm night (wind velocity, <2 m s⁻¹, 2300–700) but was evenly distributed on a windy day (>4 m s⁻¹, 1100–1900). Among many possible factors, wind velocity may have played an important role in controlling the vertical distribution of Microcystis in the lower Nakdong River. Received: July 12, 1999 / Accepted: November 15, 1999     

Statistical evaluation of dendritic growth models

A mathematical model (Kliemann, W. 1987.Bull. math. Biol. 49, 135–152.) that predicts the quantitative branching pattern of dendritic tree was evaluated using the apical and basal dendrites of rat hippocampal neurons. The Wald statistics for χ²-test was developed for the branching pattern of dendritic trees and for the distribution of the maximal order of the tree. Using this statistic, we obtained a reasonable, but not excellent, fit of the mathematical model for the dendritic data. The model's predictability of branching patterns was greatly enhanced by replacing one of the assumptions used for the original model “splitting of branches for all dendritic orders is stochastically independent”, with a new assumption “branches are more likely to split in areas where there is already a high density of branches”. The modified model delivered an excellent fit for basal dendrites and for the apical dendrites of hippocampal neurons from young rats (30–34 days postpartum). This indicates that for these cells the development of dendritic patterns is the result of a purely random and a systematic component, where the latter one depends on the density of dendritic branches in the brain area considered. For apical dendrites there is a trend towards decreasing pattern predictability with increasing age. This appears to reflect the late arrival of afferents and subsequent synaptogenesis proximal on the apical dendritic tree of hippocampal neurons.     

Modulating effect of dopamine on amplitude of GABA-produced chemocontrolled currents in multipolar spinal cord neurons of ammocaete

By using the patch-clamp method in the whole cell configuration, modulating effect of dopamine on GABA-activated currents has been studied on isolated multipolar spinal cord neurons of the ammocaete (larva of the lamprey Lampetra planeri). At application of dopamine (5 μM), there was observed in some cases a decrease of the GABA-activated current, on average, by 33.3 ± 8.7% (n = 8, p < 0.01), in other cases—an increase of the amplitude, on average, by 37.3 ± 11.8% (n = 5, p < 0.01). Concentration of GABA amounted to 2 mM. Study of action of agonists of D1- and D2-receptors on amplitude of chemocontrolled currents has shown that agonist of D1-receptors (+)-SKF-38393 (5 μM) decreases the GABA-activated current amplitude, on average, by 63.1 ± 11.7% (n = 8, p s< 0.01); the agonist of D2-receptors (−)-quinpirole (5 μM) produces in various cells the dopamine-like effects: an increase of the GABA-activated current amplitude, on average, by 61.0 ± 13.8% (n = 8, p < 0.01) and a decrease of amplitude, on average, by 55.7 ± 2.0% (n = 6, p < 0.01). It has been shown that antagonist of D2-receptors sulpiride (5 μM) does not block effects produced by dopamine. The dopamine effects were partially blocked by antagonist of D1-receptors (+)-SCH-23390 (5 μM): a decrease of the GABA-activated amplitude current amounted, on average, to 11.7 ± 1.8% (n = 7, p < 0.01), while an increase of amplitude—8.3 ± 2.0% (n = 5, p < 0.01). At the same time, effects of agonist of D1-receptors quinpirole (5 μM) were partially blocked by antagonist of D1-receptors (+)-SCH-23390: a decrease of the GABA-activated current amplitude amounted, on average, to 9.2 ± 3.4% (n = 6, p < 0.01) and an increase of amplitude—6.3 ± 1.8% (n = 10, p < 0.01). The obtained data indicate differences of mechanisms of the receptor-mediated effect of agonists of dopamine receptors on GABA-activated and potential-activated currents of multipolar neurons of the ammocaete spinal cord.     

Spiny versus stubby: 3D reconstruction of human myenteric (type I) neurons

We have compared the three-dimensional (3D) morphology of stubby and spiny neurons derived from the human small intestine. After immunohistochemical triple staining for leu-enkephalin (ENK), vasoactive intestinal peptide (VIP) and neurofilament (NF), neurons were selected and scanned based on their immunoreactivity, whether ENK (stubby) or VIP (spiny). For the 3D reconstruction, we focused on confocal data pre-processing with intensity drop correction, non-blind deconvolution, an additional compression procedure in z-direction, and optimizing segmentation reliability. 3D Slicer software enabled a semi-automated segmentation based on an objective threshold (interrater and intrarater reliability, both 0.99). We found that most dendrites of stubby neurons emerged only from the somal circumference, whereas in spiny neurons, they also emerged from the luminal somal surface. In most neurons, the nucleus was positioned abluminally in its soma. The volumes of spiny neurons were significantly larger than those of stubby neurons (total mean of stubbies 806 ± 128 μm³, of spinies 2,316 ± 545 μm³), and spiny neurons had more dendrites (26.3 vs. 11.3). The ratios of somal versus dendritic volumes were 1:1.2 in spiny and 1:0.3 in stubby neurons. In conclusion, 3D reconstruction revealed new differences between stubby and spiny neurons and allowed estimations of volumetric data of these neuron populations.     

Identification,distribution and occurrence of the ascomycete <Emphasis Type="Italic">Metschnikowia typographi</Emphasis> in the great spruce bark beetle, <Emphasis Type="Italic">Dendroctonus micans</Emphasis>

This is the first report on the ascomycete Metschnikowia typographi from the adults and larvae of the great spruce bark beetle Dendroctonus micans in Turkey. In total, 910 of 1928 adults and 44 of 149 larvae investigated during the two years were infected by the pathogen. In a fresh smear the asci of the pathogen measure 18.5 ± 2.05 μm (14.7–22.3) in length and 2.1 ± 0.4 μm in width (n = 35). The ascospores are about 2 μm shorter than asci, having an average length of 16.4 ± 1.5 μm (14.2–18.0). The total infection rate of D. micans was 47.2 %. The prevalence of M. typographi infections differed between localities and years. Different infection rates of male and female beetles of D. micans were not recognized.     

Branching dendrites with resonant membrane: a “sum-over-trips” approach

Dendrites form the major components of neurons. They are complex branching structures that receive and process thousands of synaptic inputs from other neurons. It is well known that dendritic morphology plays an important role in the function of dendrites. Another important contribution to the response characteristics of a single neuron comes from the intrinsic resonant properties of dendritic membrane. In this paper we combine the effects of dendritic branching and resonant membrane dynamics by generalising the “sum-over-trips” approach (Abbott et al. in Biol Cybernetics 66, 49–60 1991). To illustrate how this formalism can shed light on the role of architecture and resonances in determining neuronal output we consider dual recording and reconstruction data from a rat CA1 hippocampal pyramidal cell. Specifically we explore the way in which an I _h current contributes to a voltage overshoot at the soma.     

Selenium levels in blood of Upper Silesian population

The selenium status and the relationship of whole-blood selenium and plasma homocysteine are reported for healthy human subjects living in Upper Silesia. A total of 1063 individuals (627 male and 436 female) examined for whole-blood selenium were subdivided into six groups according to age; the youngest included adolescents (n=143) aged 10–15 yr, and the oldest were centenarians (n=132). The mean Se content was relatively low (62.5±18.4 μg/L), and it tended to be higher in men (65.9±17.2 μg/L) than in women (57.5±18.9 μg/L). Selenium levels appeared to be age dependent, as the highest values were observed in young and middle-age adults (21–40 yr), whereas they were significantly lower in adolescents and in the elderly. In more than 40% of apparently healthy adults (aged 21–69 yr), the Se concentration was within the range 60–80 μg/L (i.e., below the lower limit of the nutritional adequacy range [80 μg/L]). A significant inverse correlation between whole-blood selenium and plasma total homocysteine was detected in a smaller population sample of middle-aged and elderly persons (n=204).     

Sensitive and rapid HPLC quantification of tenofovir from hyaluronic acid-based nanomedicine

The purpose of this study was to develop and validate a rapid, sensitive, and specific reversed-phase high-performance liquid chromatography method for the quantitative determination of native tenofovir (TNF) for various applications. Different analytical performance parameters such as linearity, precision, accuracy, limit of quantification (LOQ), limit of detection (LOD), and robustness were determined according to International Conference on Harmonization (ICH) guidelines. A Bridge™ C18 column (150 × 4.6 mm, 5 μm) was used as stationary phase. The retention time of TNF was 1.54 ± 0.03 min (n = 6). The assay was linear over the concentration range of 0.1–10 μg/mL. The proposed method was sensitive with LOD and LOQ values equal to 50 and 100 ng/mL, respectively. The method was accurate with percent mean recovery from 95.41% to 102.90% and precise as percent RSD (relative standard deviation) values for intra-day, and inter-day precision were less than 2%. This method was utilized for the estimation of molar absorptivity of TNF at 259 nm (ε ₂₅₉ = 12,518 L/mol/cm), calculated from linear regression analysis. The method was applied for determination of percentage of encapsulation efficiency ( 22.93 ± 0.04%), drug loading (12.25 ± 1.03%), in vitro drug release profile in the presence of enzyme (43% release in the first 3 h) and purification analysis of hyaluronic acid-based nanomedicine.     

Impact of medium volume and oxygen concentration in the incubator on pericellular oxygen concentration and differentiation of murine chondrogenic cell culture

Previous studies have demonstrated that oxygen environment is an important determinate factor of cell phenotypes and differentiation, although factors which affect pericellular oxygen concentration (POC) in murine chondrogenic cell culture remain unidentified. Oxygen concentrations in vivo were measured in rabbit musculoskeletal tissues, which were by far hypoxic compared to 20% O₂ (ranging from 2.29 ± 1.16 to 4.36 ± 0.51%). Oxygen concentrations in murine chondrogenic cell (C3H10T1/2) culture medium were monitored in different oxygen concentrations (20% or 5%) in the incubator and in different medium volumes (3,700 or 7,400 μl) within 25-cm² flasks. Chondrogenic differentiation was assessed by glycosaminoglycan production with quantitative evaluation of Alcian blue staining in 12-well culture dishes. Expression of chondrogenic genes, aggrecan, and type II collagen α1, was examined by quantitative real-time polymerase chain reaction. Oxygen concentrations in medium decreased accordingly with the depth from medium surface, and POC at Day 6 was 18.99 ± 0.81% in 3,700-μl medium (1,480-μm depth) and 13.26 ± 0.23% in 7,400-μl medium (2,960-μm depth) at 20% O₂ in the incubator, which was 4.96 ± 0.08% (1,480-μm depth) and 2.83 ± 0.42% (2,960-μm depth) at 5% O₂, respectively. The differences of POC compared by medium volume were statistically significant (p = 0.0003 at 20% and p = 0.001 at 5%). Glycosaminoglycan production and aggrecan gene expression were most promoted when cultured in moderately low POC, 1,000 μl (2,960-μm depth) at 20% O₂ and 500 μl (1,480-μm depth) at 5% O₂ in 12-well culture dishes. We demonstrate that medium volume and oxygen concentration in the incubator affect not only POC but also chondrogenic differentiation.     

Effect of of ATP on Neurons of the Rat Intact Nodose Ganglion

Under intracellular recording, we studied the effect of ATP on nerve cells of the rat intact nodose ganglion. The resting membrane potential of the examined neurons was, on average, –60.3 ± 1.4 mV (n = 84); among such units, 88% were classified as C cells. Local application of 2 mM ATP to the surface of the ganglion using a modified laminar flow system led to depolarization of neurons by 7.1 ± 0.9 mV, on average (n = 19). A blocker of P2X receptors, PPADS (100 μM), suppressed these depolarization responses, decreasing their amplitude, on average, to 16 ± 3% (n = 3) of the initial value. The obtained data indicate that an overwhelming majority of neurons of the intact nodose ganglion possess functional P2X receptors on their membranes. The absence of the corresponding responses in a considerable part of neurons of intact spinal ganglia [13-15] was, apparently, determined by the fact that P2X receptors in the course of the described experiments had enough time to desensitize before ATP reached the effective concentration.     

Effects of Environmental Lead Pollution, Smoking, and Smokeless Tobacco (Maras Powder) Use on Blood Lead Level

One hundred sixty-four adult male volunteers (29 controls [Group 1] and 135 combi drivers) enrolled in the study. The combi drivers were divided into three groups as nonusers of either Maras powder or cigarette (Group 2), smokers (Group 3), and users of Maras powder (Group 4). Blood lead levels (BLLs) were analyzed by atomic absorption spectrophotometer. BLL was detected as 2.8 ± 2.3 μg/dL in Group 1 (n = 29); however, it was 3.5 ± 1.6 μg/dL in Group 2 (n = 33), 3.8 ± 2.4 μg/dL in Group 3 (n = 62), and 3.9 ± 2.4 μg/dL in Group 4 (n = 40). BLL in Group 1 was found significantly lower than other groups (p < 0.05). The use of cigarette or Maras powder by the drivers did not give rise to a marked difference on the BLLs (p > 0.05). BLL of (combi) drivers was detected to be significantly higher than nondrivers; however, it was still under the hazardous level of 10 μg/dL announced by WHO. Although there are publications reporting that usage of tobacco increases the level of lead in blood, both smoking and use of Maras powder did not affect BLL markedly in our study. Poster presented (the abstract section published in Congress Book) at the 7th Congress of Turkish Family Physicians, 23–26 May 2006, Cesme-IZMIR, Turkey.     

Neuronal Types in the Human Anterior Ventral Thalamic Nucleus: A Golgi Study

Neurons in the anterior ventral (AV) thalamic nucleus of human adults were impregnated by Golgi-Kopsch impregnation method. Results showed that at least three morphological types of neurons could be recognized in the human AV thalamic nucleus. Type I neurons were medium to large with rich dendritic arborization. Both tufted and radiating dendritic branching patterns were seen in almost every neuron of this type. Only the initial axonal segments of these cells were impregnated suggesting that these axons were heavily myelinated. Type II neurons were medium in size with poor to moderate dendritic arborization. Many of these cells possess a few dendritic grape-like appendages. Long segments (up to 300 μm) of their axons were impregnated suggesting that these axons were either unmyelinated or thinly myelinated. These axons change their direction and form loops very often. No local branches were seen for these axons suggesting that they could be projection axons. Type III neurons were small with only one or two dendrites with poor arborization. No axons for these cells were seen in this study. The three neuronal types in the human AV thalamic nucleus were compared with neuronal types already described in other thalamic nuclei of human and non-human species. The results of this study might provide a morphological basis for further electrophysiological and / or pathological studies.     

Contribution to the Data on Copper Concentration in Blood and Urine in Patients with Wilson’s Disease and in Normal Subjects

Determination of copper in human tissues and body fluids may be crucial in the diagnosis of Wilson’s disease. In this study we evaluated urinary copper excretion and urine and blood concentration in 14 patients in whom Wilson’s disease was confirmed (group A) and in 21 subjects in whom the disease was only suspected (group B). The following values (mean ± SD) were found: 24-h urine (μg Cu/24 h), 152 ± 135 (A) and 31.8 ± 10.9 (B); urine (μg Cu/ml), 0.091 ± 0.087 (A) and 0.028 ± 0.011 (B); and blood (μg Cu/ml), 0.62 ± 0.25 (A) and 0.72 ± 0.09 (B). By comparison, urine copper concentration in the group of apparently healthy subjects was 0.035 ± 0.010 (n = 50), and blood copper concentration in autopsy cases of nonpoisoned people was 0.85 ± 0.19 (n = 73).     

Operant reflexes and expression of the <Emphasis Type="Italic">c-fos</Emphasis> gene in the amygdalar nuclei and insular cortex of rats

We studied manifestations of increased neuronal activity in the limbic structures of the rat brain related to realizations of operant reflexes by the animals. After rats had performed repeated operant foodprocuring movements, the mean numbers of Fos-immunoreactive neurons within sections of the central and basolateral amygdalar nuclei, insular cortex, substantia innominata, and paraventricular hypothalamic nucleus significantly exceeded the control values. In the ipsilateral (with respect to the working forelimb) central nucleus of the amygdala, the mean number of such neurons within a 40-μm-thick slice was nearly an order of magnitude greater than in the control (42.2 ± 2.4 and 4.5 ± 0.4 labeled units, respectively). In the agranular insular and granular/disgranular cortical zones at the contralateral site, the numbers of labeled neurons exceeded control values by about three times (94.6 ± 8.2 vs 31.6 ± 2.2 and 103.5 ± 4.5 vs 39.6 ± ± 2.4 immunopositive cells, respectively). These findings confirm the hypothesis on the direct involvement of the subcortical structures and limbic cortex zones in the control of somato-cardiovascular integration during the performance of operant reflexes by the animals.     

Aerodynamic particle size analysis of aerosols from pressurized metered-dose inhalers: Comparison of andersen 8-stage cascade impactor,next generation pharmaceutical impactor,and model 3321 aerodynamic particle sizer aerosol spectrometer

The purpose of this research was to compare three different methods for the aerodynamic assessment of (1) chloroflurocarbon (CFC)-fluticasone propionate (Flovent), (2) CFC-sodium cromoglycate (Intal), and (3) hydrofluoroalkane (HFA)-beclomethasone dipropionate (Qvar) delivered by pressurized metered dose inhaler. Particle size distributions were compared determining mass median aerodynamic diameter (MMAD), geometric standard deviation (GSD), and fine particle fraction <4.7 μm aerodynamic diameter (FPF_{<4.7 μm}). Next Generation Pharmaceutical Impactor (NGI)-size distributions for Flovent comprised finer particles than determined by Andersen 8-stage impactor (ACI) (MMAD=2.0±0.05 μm [NGI]; 2.8±0.07 μm [ACI]); however FPF_{<4.7 μm} by both impactors was in the narrow range 88% to 93%. Size distribution agreement for Intal was better (MMAD=4.3±0.19 μm (NGI), 4.2±0.13 μm (ACI), with FPF_{<4.7 μm} ranging from 52% to 60%. The Aerodynamic Particle Sizer (APS) undersized aerosols produced with either formulation (MMAD=1.8±0.07 μm and 3.2±0.02 μm for Flovent and Intal, respectively), but values of FPF_{<4.7 μm} from the single-stage impactor (SSI) located at the inlet to the APS (82.9%±2.1% [Flovent], 46.4%±2.4% [Intal]) were fairly close to corresponding data from the multi-stage impactors. APS-measured size distributions for Qvar (MMAD=1.0±0.03 μm; FPF_{<4.7 μm}=96.4% ±2.5%), were in fair agreement with both NGI (MMAD=0.9±0.03 μm; FPF_{<4.7 μm}=96.7%±0.7%), and ACI (MMAD=1.2±0.02 μm, FPF_{<4.7 μm}=98%±0.5%), but FPF_{<4.7 μm} from the SSI (67.1%±4.1%) was lower than expected, based on equivalent data obtained by the other techniques. Particle bounce, incomplete evaporation of volatile constituents and the presence of surfactant particles are factors that may be responsible for discrepancies between the techniques.     

Karyotype study in <Emphasis Type="Italic">Luzuriaga radicans</Emphasis> (Liliales: Luzuriagaceae)

The karyotype of Luzuriaga radicans R. & P. was quantitatively studied, assessing characters such as chromosome morphology and size, satellite location, asymmetry level and bimodality. L. radicans has an asymmetric and bimodal karyotype 2n = 20 with three metacentric pairs, followed by six submetacentric and one subtelocentric chromosome pair. One satellite was observed in the short arm of chromosome pair 6. The total haploid set length was 48.7 μm and the mean chromosome size was 4.87 ± 2.35 μm. Comparing L. radicans with other two species of the genus a high resemblance among their karyotypes was found.     

Morphological characteristics of different types of neurons in the ventrooralis anterior,ventrooralis internus,and ventrooralis posterior nuclei in the human thalamus

1. Golgi-Kopsch preparations of the oral ventral nuclei of human thalamus were analyzed in an attempt to classify the neuronal types. 2. Three types of neurons are described for the first time in humans. Type I neurons are large or medium in size and bear dendrites with protrusions, spines, and short hair-like appendages. Some have a radiate dendritic arbor and others have dendrites grouped in tufts. The dendritic trees of these neurons are dense. 3. Type II neurons are medium or small in size with less dense dendritic trees. These cells have somatic as well as dendritic appendages of different forms. 4. Relatively rare is a type of very small neurons, type III, with few and sparsely branching dendrites.     

Zinc in Postmortem Body Tissues and Fluids

Data on zinc concentration in the human body may be used to interpret the results obtained in cases of chronic and acute poisonings with zinc compounds, i.e., in clinical and forensic toxicology. In this paper, the concentrations of zinc in human tissues and body fluids obtained from autopsy cases concerning non-poisoned people (n = 203), aged from 14 to 80 years, between 1995 and 2008, are presented. The following values were found by the flame atomic absorption method (mean ± SD, median, range, in microgram per gram or microgram per milliliter): brain 10.3 ± 1.36, 10.2, 7.99–13.8 (n = 48); stomach 14.2 ± 3.63, 13.6, 8.00–22.5 (n = 71); intestines 15.7 ± 5.22, 15.8, 8.36–28.1 (n = 35); liver 39.6 ± 16.1, 36.6, 16.0–78.8 (n = 109); kidney 33.8 ± 10.1, 31.8, 16.4–60.9 (n = 93); lung 12.0 ± 3.88, 11.0, 6.13–18.7 (n = 26); spleen 14.7 ± 2.53, 14.6, 11.4–18.3 (n = 5); heart 26.5 ± 3.63, 26.7, 22.5–31.8 (n = 5); blood 6.81 ± 1.21, 7.00, 4.02–8.68 (n = 50); urine 0.69 ± 1.70, 0.60, 0.39–1.00 (n = 5), and bile 4.92 ± 1.64, 3.75, 3.20–7.09 (n = 9). The accuracy of the method was checked through the use of SRM Bovine Liver 1577b (certified: 127 ± 16 μg Zn/g, found: 117 ± 0.7 μg Zn/g (n = 6)).     

Morphological differences among three species of newly settled pocilloporid coral recruits

 Investigation of the life history of corals is hampered by an inability to identify early recruits. In this study, the pattern of formation and morphology of the juvenile skeletons of three laboratory-reared pocilloporids, Seriatopora hystrix, Stylophora pistillata and Pocillopora damicornis, were compared to determine whether they could be reliably distinguished. The pattern of skeleton formation, including the origin and structure of the septa, columella and corallite wall was similar in all species. Following the completion of the primary corallite wall after 4–5 days, these species could be identified by differences in the diameter of the primary corallite. The mean diameter (±SE) of each species differed markedly: S. hystrix 400 ± 2.7 μm, range 325–450 μm; S. pistillata 505 ± 3.5 μm, range 400–550 μm; P. damicornis 697 ± 7.5 μm, range 492–885 μm. Values for the primary corallite diameter overlapped in only 3% of samples, demonstrating the potential utility of this feature as a tool for classifying recruits obtained from the field. Accepted: 4 January 2000     

Electrical Bistability of the Motoneuronal Dendritic Membrane Determined by Non-inactivating Inward Currents: a Model Study

We investigated features of the spatial pattern of electrical bistable states of dendrites using a computer model of an abducens motoneuron with the dendritic branching reconstructed in detail. The dendritic membrane has an N-shaped current-voltage relation (I-V curve) determined mainly by the presence of L-type calcium channels. Such channels, according to indirect experimental data, are present in the dendrites of these cells together with glutamatergic NMDA-type channels also capable of determining electrical bistability of the membrane and the corresponding specific patterns of electrical activity generated by such neurons. For our model, we obtained steady-state local I-V curves and transferred spatial distribution maps of the membrane potential difference (surface density of transmembrane currents), as well as increments of the axial dendritic current, to three-dimensional images of the reconstructed branching dendrites. The latter increments determine the contribution of a dendritic site in general axial current delivering the charge to the trigger zone of a neuron. The simulation results showed that incorporation of non-inactivating calcium channels into dendritic membrane leads to the origination of a pattern of spatial distribution of bistable electrical states in the dendrites, which were not described earlier. Such features are most important under conditions of a stable state of high depolarization of the relevant parts of the dendrites. In this case, the respective feature was the existence of a zone of maximum density of the inward transmembrane current, which covers areas of first-order branching of all dendrites. Since the greatest relative contribution to the total current belongs to the inward calcium current, the above zone of first branchings can be considered a “hot spot” zone characterized by increased entry of Ca²⁺. This may have important functional consequences for local intracellular calcium signaling.