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Donaldson LA, Nanayakkara B, Radotić K, Djikanovic-Golubović D, Mitrović A, Bogdanović Pristov J, Simonović Radosavljević J, Kalauzi A. Xylem parenchyma cell walls lack a gravitropic response in conifer compression wood. Planta 2015; 242:1413-1424. [PMID: 26287313 DOI: 10.1007/s00425-015-2381-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/24/2015] [Indexed: 06/04/2023]
Abstract
Cell wall fluorescence and immunocytochemistry demonstrate that xylem parenchyma cell walls do not show changes in structure and composition related to gravitropic response comparable to those of tracheids, even when they have lignified secondary cell walls. Tracheid cell walls in compression wood have altered composition and structure which generates the strain responsible for correction of stem lean as part of the gravitropic response of woody plants. Xylem parenchyma cell walls vary among conifer species and can be lignified secondary walls (spruce) or unlignified primary walls (pine). It can be expected that xylem parenchyma with lignified secondary cell walls might show features of compression wood comparable to those of tracheids that have a similar type of cell wall. A comparison of xylem parenchyma cell walls in normal and compression wood in species with lignified and non-lignified parenchyma cell walls provides a unique opportunity to understand the process of reaction wood formation in conifers. Using both UV/visible fluorescence microscopy of cell wall fluorophores and immunocytochemistry of galactan and mannan epitopes, we demonstrate that xylem parenchyma cell walls do not show the changes in composition and structure typical of compression wood tracheids. Adjacent cells of different types but with similar cell wall structure can undergo cell wall developmental changes related to support or defence functions independent of their neighbours. Tracheids are sensitive to gravitropic signals while xylem parenchyma cells are not.
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Affiliation(s)
| | | | - K Radotić
- Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
| | | | - A Mitrović
- Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
| | - J Bogdanović Pristov
- Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
| | | | - A Kalauzi
- Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
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Lazic K, Petrovic J, Ciric J, Kalauzi A, Saponjic J. Impact of anesthetic regimen on the respiratory pattern, EEG microstructure and sleep in the rat model of cholinergic Parkinson’s disease neuropathology. Neuroscience 2015; 304:1-13. [DOI: 10.1016/j.neuroscience.2015.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 07/06/2015] [Accepted: 07/07/2015] [Indexed: 11/29/2022]
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Algarra M, Radotić K, Kalauzi A, Alonso B, Casado C, Esteves da Silva J. Component analysis of fluorescence spectra of thiol DAB dendrimer/ZnSe-PEA nanoparticles. Talanta 2013; 105:267-71. [DOI: 10.1016/j.talanta.2012.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 08/30/2012] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
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Kalauzi A, Kesic S, Saponjic J. Cortico-pontine theta synchronization phase shift following monoaminergic lesion in rat. J Physiol Pharmacol 2009; 60:79-84. [PMID: 20065500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Accepted: 11/06/2009] [Indexed: 05/28/2023]
Abstract
The experiments were performed in 14 adult, male Sprague Dawley rats chronically instrumented for sleep recording and recorded during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. In our former study we demonstrated that the systemically induced lesion of the noradrenergic or serotonergic axon terminals did not affect the sleep-wake distribution from control condition. In this study, by using spectral analysis and phase shift spectra of the cortical and pontine EEG we analyzed cortico-pontine theta oscillation synchronization phase shift on 6-hour recordings in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Our results demonstrated for the first time that chronically decreased brain monoamines in freely moving rats changed cortico-pontine theta synchronization phase shift. Pons became a leading theta oscillator. We assume that deficit of monoamines induced predominance of the NREM/REM transitions, characterized with phasic theta oscillations (the increased density of clustered P waves which intrinsic frequency corresponds to theta frequency oscillations), and may produced preceding phasic theta versus tonic theta oscillation drive.
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Affiliation(s)
- A Kalauzi
- Department of Life Sciences, Institute for Multidisciplinary Research, 11000 Belgrade, Serbia
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Čukic M, Kalauzi A, Ljubisavljević M. 9. Analysis of probability density distributions of TMS induced physiological parameters. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cukic M, Kalauzi A, Ilic T, Miskovic M, Ljubisavljevic M. The influence of coil-skull distance on transcranial magnetic stimulation motor-evoked responses. Exp Brain Res 2008; 192:53-60. [PMID: 18787813 DOI: 10.1007/s00221-008-1552-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 08/14/2008] [Indexed: 11/30/2022]
Abstract
We have investigated the effects of changing the coil-to-skull distance on the motor-evoked responses (MEP) induced with two different magnetic stimulator coils (80 mm round and figure-of-eight coil) at rest and during voluntary muscle contraction. The changes in MEP latency, amplitude and silent period (SP) duration induced by stimulation directly upon the skull, and 1 cm away from the skull were analyzed by computing the probability density distribution (PDD) for the responses obtained from all subjects. This measure corresponds to the finite probability that the event occurs within a given area. Overall, the results were consistent with a distance-induced decrease in magnetic field strength. However, the increase in coil-to-skull distance induced a higher probability of longer latencies in active muscle when stimulating with either coil. Also, stimulating at a distance with the figure-of-eight coil increased the probability of a longer SP duration. The stimulation strength at the two distances was comparable because it was set based on the motor threshold obtained for each distance. Therefore, our results are not entirely compatible with the established exponential drop in magnetic field with increasing distance. Rather, they suggest that a more complex set of interactions occurs in the cortex. The results imply that distinct patterns of cortical network activation may exist related to the distance-induced alterations when the coil is moved away from the skull. Further studies are required to elucidate the precise nature of the distance-related interactions of the magnetic field with the cortex.
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Affiliation(s)
- M Cukic
- Department of Neurophysiology, Institute for Medical Research, Belgrade, PO Box 11121, Serbia
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Djikanović D, Kalauzi A, Radotić K, Lapierre C, Jeremić M. Deconvolution of lignin fluorescence spectra: A contribution to the comparative structural studies of lignins. Russ J Phys Chem 2007. [DOI: 10.1134/s0036024407090142] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
With application of the Higuchi algorithm, fractal dimension (FD) values of the electrocortical activity of the rat parietal cerebral and paravermal cerebellar cortex were calculated, before and after unilateral discrete injury of the left parietal cortex. Immediately following the first acute injury, in a group of six rats, a reversible increase in mean FD was found at the left (ipsilateral side to the injury) cerebral cortex, from 1.38 to 1.59, and at the left cerebellar cortex from 1.51 to 1.73. In addition, an indication of plastic changes after repeated (third) injury was found as an irreversible increase in mean FD: 1.54 on the left and 1.48 on the right side of parietal cortex.
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Affiliation(s)
- S Spasic
- Center for Multidisciplinary Studies, University of Belgrade, Belgrade, Serbia and Montenegro.
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Kalauzi A, Spasic S. Estimation of neuronal population activity changes in rat cerebellum using one electrode. Comp Biochem Physiol A Mol Integr Physiol 2004; 138:61-8. [PMID: 15165572 DOI: 10.1016/j.cbpb.2004.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Revised: 01/22/2004] [Accepted: 02/27/2004] [Indexed: 10/26/2022]
Abstract
Activity of neuronal populations is usually measured with multielectrode systems. In this paper a procedure is described for estimating population activity changes in rat cerebellar cortex, using one microelectrode. Signals consisted of simple, complex spikes and interspike recorded background activity (RBA). After their separation, simple spikes were averaged, forming a simple spike template (SST). The remaining RBA was simulated (SBA), by superimposing SST waveforms with random time delays and intensities. A series of SBA was formed, differing in the superposition frequency (f(sup)) of individual SST. Mean amplitude spectra (Amp(SBA)) were calculated and Amp(SBA)=f(f(sup)) treated as a calibration line for estimating activity level of the surrounding neuronal population. Since the uniform probability distribution of SST intensities proved inadequate, we derived a new one, based on the power function for spike intensity vs. electrode distance attenuation. A family of new lines emerged, depending on the model parameters. Since all were linear in the log-log plots, with slopes not varying significantly, we proposed a method for estimating population activity changes in different experimental conditions, using two measured values of Amp(RBA). Relative nature of the results makes this method suitable for comparative studies.
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Affiliation(s)
- A Kalauzi
- Department for Biophysics, Neuroscience and Biomedical Engineering, Center for Multidisciplinary Studies, University of Belgrade, 29. novembra 142, 11000 Belgrade, Serbia and Montenegro.
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Marković DZ, Kalauzi A, Radenović CN. Delayed fluorescence induction transients: mathematical modelling based on the chosen kinetic models. Gen Physiol Biophys 2001; 20:303-13. [PMID: 11765220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The paper deals with mathematical modelling of the transients obtained by fitting of delayed fluorescence (DF) induction trace. The transients are in certain, doubtless connection with electrochemical gradient (ECG) formed across thylakoid membranes upon illumination. The fitting of the C and D transients by using consecutive model for first-order reactions (A --> B --> C) showed that they might play a role of the intermediate (B), according to scheme down bellow: ("A1 state")ECG (k1(C transient))--> C transient (k2(C transient))--> products, ("A2 state")ECG (k1(D transient))--> D transient (k2(D transient))--> products. The two ECG controlled "states" (A1 & A2) are not the same, which does not exclude some sort of proportionality. On the other hand, the E band, contributing mainly to the stationary level of DF induction trace, may be fitted by parallel model of at least two first-order reactions.
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Affiliation(s)
- D Z Marković
- Faculty of Technology, University of Nish, Leskovac, Serbia-Yugoslavia.
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Arambašić M, Ristanović D, Kalauzi A. The Comparison of Some Empirical Functions of Growth Using Pond Snail Lymnaea Stagnalis L. as an Example. Biom J 1988. [DOI: 10.1002/bimj.4710300814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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