scholarly journals Effects of long term exposure to aluminium stress on the accumulation and distribution of K+, Na+, Ca2+, Mg2+, Fe2+ and Clin rice and chickpea plants

2018 ◽  
Vol 27 (1) ◽  
pp. 37-48
Author(s):  
Rifat Samad ◽  
Parveen Rashid ◽  
JL Karmoker
Keyword(s):  
Inhibitory Effect ◽  
Mineral Nutrients ◽  
Sand Culture ◽  
Nutrients Uptake ◽  
Maximum Inhibition ◽  
Al Treatment ◽  
Different Parts ◽  
Stimulation Of

Sand culture experiments were undertaken to examine the effect of increasing aluminium levels (50-150 μM) on the mineral nutrients uptake (K+, Na+, Ca2+, Mg2+, Fe2+ and Cl-). Increasing concentrations of Al inhibited the uptake of K+, Ca2+, Mg2+ and Fe2+ but enhanced that of Na+ and Cl- in the root and shoot of rice, and the root, stem and leaves of chickpea. 150 μM Al caused a maximum inhibition of K+ accumulation in the root and shoot of rice ranging from 25.5 to 49.0% and 33 to 55.5%, respectively, from 7 to 28 day of treatment. In the root, stem and leaves of chickpea, 150 μM Al inhibited K+ content by 23.9 to 84.0%, 13.2 to 54.4% and 25.3 to 61.2%, respectively, from 7 to 28 day of application. On the contrary, a dramatic 2.7 to 3.1-folds and 70.8% to 2.3-folds stimulation of Na+ accumulation was recorded in the root of rice and chickpea, respectively, following 100 μM Al treatment from 7 to 28 day of treatment. Different concentrations of aluminium led to a stimulation of Cl- accumulation in different parts of rice and chickpea plants. In rice and chickpea plants, the inhibitory effect of aluminium stress on the accumulation of Ca2+, Mg2+ and Fe2+ was enhanced with the increase in Al concentration from 50 to 150 μM. Dhaka Univ. J. Biol. Sci. 27(1): 37-48, 2018 (January)

The Development of Patterned Activity by implanted Ganglia and their Peripheral Connexions in Periplaneta Americana

1969 ◽  
Vol 50 (1) ◽  
pp. 255-273
Author(s):  
D. M. GUTHRIE ◽  
J. R. BANKS
Keyword(s):  
Periplaneta Americana ◽  
Functional Relationship ◽  
Low Frequency ◽  
Inhibitory Effect ◽  
Sense Organs ◽  
Steady Level ◽  
The Central Nervous System ◽  
Stimulation Of

1. The isolation of a thoracic ganglion from the rest of the central nervous system results in a loss of differentiation of the motor output, although repetitive rhythms may appear during the later stages of isolation. Total isolation of the ganglion in vitro results in a further reduction of motor activity to low-frequency, steady-level discharges in a few fibres of some nerves only. 2. Two or three months after implantation a steady low-frequency discharge can be recorded from many of the branches of the implant ganglion, and these may have functional contacts with adjacent muscles. There is little evidence of afferent connexions. 3. Four to seven months after implantation the efferent connexions of the implanted ganglion often show a highly differentiated pattern of spontaneous electrical activity, and the ganglion will respond in a remarkably delayed and progressive manner to the stimulation of adjacent sense organs. 4. The spontaneous rhythms of the long-term implant ganglion may be determined by a balance between central and peripheral input levels similar to those occurring during progressive isolation of the ganglion. 5. The functional relationship between the host and the donor ganglion appears to consist largely of an inhibitory effect exerted by the host ganglion on the donor or implant ganglion. A justification for this in adaptive terms can be found.

Deletion of Kir5.1 abolishes the effect of high-Na+-intake on Kir4.1 and Na-Cl-cotransporter.

2021 ◽  
Author(s):  
Xin-Peng Duan ◽  
Peng Wu ◽  
Dan-Dan Zhang ◽  
Zhong-Xiuzi Gao ◽  
Yu Xiao ◽  
...  
Keyword(s):  
Excretion Rate ◽  
Sodium Intake ◽  
Reversal Potential ◽  
Inhibitory Effect ◽  
Distal Nephron ◽  
High Sodium ◽  
Expression Activity ◽  
Epithelial Sodium Channel Enac ◽  
Stimulation Of

High-sodium-intake (HS) inhibited epithelial-sodium-channel (ENaC) in the aldosterone-sensitive-distal-nephron (ASDN) and Na+-Cl--cotransporter (NCC) by suppressing basolateral Kir4.1/Kir5.1 in the distal-convoluted-tubule (DCT) thereby increasing renal Na+ excretion but not affecting K+ excretion. The aim of the present study is to explore whether the deletion of Kir5.1 compromises the inhibitory effect of HS on NCC expression/activity and renal K+-excretion. Patch-clamp experiments demonstrated that HS failed to inhibit DCT-basolateral K+ channels and did not depolarize K+-currents (IK) reversal-potential of the DCT in Kir5.1 knockout (Kir5.1 KO) mice. Moreover, deletion of Kir5.1 not only increased the expression of Kir4.1, phosphor-NCC (pNCC) and total NCC (tNCC) but also abolished the inhibitory effect of HS on the expression of Kir4.1, pNCC and tNCC, and thiazide-induced natriuresis. Also, LS-induced stimulation of NCC expression/activity and the basolateral K+ channels in the DCT was absent in Kir5.1 KO mice. The deletion of Kir5.1 decreased ENaC currents in DCT2 and HS further inhibited ENaC activity in Kir5.1 KO mice. Finally, the measurement of basal renal K+ excretion rate with modified renal clearance method demonstrated that long-term HS inhibited renal K+ excretion rate and steadily increased plasma K+ levels in Kir5.1 KO mice but not in WT mice. We conclude that Kir5.1 plays an important role in mediating the effect of HS intake on the basolateral K+ channels in the DCT and NCC activity/expression. Kir5.1 is involved in maintaining renal ability of K+ excretion during HS intake.

scholarly journals Guanine nucleotides mediate stimulatory and inhibitory effects on cerebral-cortical membrane phospholipase C activity

1989 ◽  
Vol 261 (1) ◽  
pp. 245-251 ◽  
Author(s):  
I Litosch
Keyword(s):  
Phospholipase C ◽  
Pertussis Toxin ◽  
Inhibitory Effect ◽  
Guanine Nucleotides ◽  
Regulatory Effect ◽  
Inhibitory Effects ◽  
Gtp Binding ◽  
Maximum Inhibition ◽  
Cortical Membranes ◽  
Stimulation Of

In cerebral-cortical membranes, hydrolysis-resistant guanine nucleotides exert a dual regulatory effect on phospholipase C activity. Nanomolar concentrations of guanosine 5′-[beta gamma-imido]triphosphate (p[NH]ppG) or guanosine 5′-[gamma-thio]triphosphate (GTP[S]) inhibited basal phospholipase C activity, with a maximum inhibition of 30% at 10 nM. Increasing the concentration of p[NH]ppG or GTP[S] to over 10 nM resulted in a reversal of the inhibitory effect and onset of stimulation of phospholipase C activity. These inhibitory effects were blocked by 100 microM-guanosine 5′-[beta-thio]diphosphate. GTP was relatively ineffective in producing either stimulation or inhibition of phospholipase C activity. Similarly, ATP, adenosine 5′-[beta gamma-imido]triphosphate and GDP were also ineffective. Expression of the dual effects of guanine nucleotides was affected by the Mg2+ concentration. At 0.3 mM-Mg2+, both the inhibitory and the stimulatory components of p[NH]ppG action were evident. At 2.5 mM-Mg2+, only p[NH]ppG stimulation was observed. Pertussis-toxin treatment blocked the p[NH]ppG-mediated inhibition of phospholipase C activity. These results demonstrate that non-hydrolysable guanine nucleotides exert both a stimulatory and an inhibitory effect on membrane phospholipase C activity. These effects may be mediated through distinct GTP-binding proteins.

Deep brain stimulation of the posterior limb of the internal capsule in the treatment of central poststroke neuropathic pain of the lower limb: case series with long-term follow-up and literature review

2020 ◽  
Vol 133 (3) ◽  
pp. 830-838 ◽  
Author(s):  
Andrea Franzini ◽  
Giuseppe Messina ◽  
Vincenzo Levi ◽  
Antonio D’Ammando ◽  
Roberto Cordella ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Lower Limb ◽  
Internal Capsule ◽  
Posterior Limb ◽  
Vas Score ◽  
The Mean ◽  
Deep Brain ◽  
Stimulation Of

OBJECTIVECentral poststroke neuropathic pain is a debilitating syndrome that is often resistant to medical therapies. Surgical measures include motor cortex stimulation and deep brain stimulation (DBS), which have been used to relieve pain. The aim of this study was to retrospectively assess the safety and long-term efficacy of DBS of the posterior limb of the internal capsule for relieving central poststroke neuropathic pain and associated spasticity affecting the lower limb.METHODSClinical and surgical data were retrospectively collected and analyzed in all patients who had undergone DBS of the posterior limb of the internal capsule to address central poststroke neuropathic pain refractory to conservative measures. In addition, long-term pain intensity and level of satisfaction gained from stimulation were assessed. Pain was evaluated using the visual analog scale (VAS). Information on gait improvement was obtained from medical records, neurological examination, and interview.RESULTSFour patients have undergone the procedure since 2001. No mortality or morbidity related to the surgery was recorded. In three patients, stimulation of the posterior limb of the internal capsule resulted in long-term pain relief; in a fourth patient, the procedure failed to produce any long-lasting positive effect. Two patients obtained a reduction in spasticity and improved motor capability. Before surgery, the mean VAS score was 9 (range 8–10). In the immediate postoperative period and within 1 week after the DBS system had been turned on, the mean VAS score was significantly lower at a mean of 3 (range 0–6). After a mean follow-up of 5.88 years, the mean VAS score was still reduced at 5.5 (range 3–8). The mean percentage of long-term pain reduction was 38.13%.CONCLUSIONSThis series suggests that stimulation of the posterior limb of the internal capsule is safe and effective in treating patients with chronic neuropathic pain affecting the lower limb. The procedure may be a more targeted treatment method than motor cortex stimulation or other neuromodulation techniques in the subset of patients whose pain and spasticity are referred to the lower limbs.

scholarly journals Pre-motor versus motor cerebral cortex neuromodulation for chronic neuropathic pain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Igor Lavrov ◽  
Timur Latypov ◽  
Elvira Mukhametova ◽  
Brian Lundstrom ◽  
Paola Sandroni ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Cerebral Cortex ◽  
Motor Cortex ◽  
Initial Assessment ◽  
Motor Cortex Stimulation ◽  
Chronic Neuropathic Pain ◽  
Long Term Effect ◽  
Stimulation Of

AbstractElectrical stimulation of the cerebral cortex (ESCC) has been used to treat intractable neuropathic pain for nearly two decades, however, no standardized approach for this technique has been developed. In order to optimize targeting and validate the effect of ESCC before placing the permanent grid, we introduced initial assessment with trial stimulation, using a temporary grid of subdural electrodes. In this retrospective study we evaluate the role of electrode location on cerebral cortex in control of neuropathic pain and the role of trial stimulation in target-optimization for ESCC. Location of the temporary grid electrodes and location of permanent electrodes were evaluated in correlation with the long-term efficacy of ESCC. The results of this study demonstrate that the long-term effect of subdural pre-motor cortex stimulation is at least the same or higher compare to effect of subdural motor or combined pre-motor and motor cortex stimulation. These results also demonstrate that the initial trial stimulation helps to optimize permanent electrode positions in relation to the optimal functional target that is critical in cases when brain shift is expected. Proposed methodology and novel results open a new direction for development of neuromodulation techniques to control chronic neuropathic pain.

Electrical stimulation of referred sensation area alleviates phantom limb pain

2021 ◽  
pp. 1-10
Author(s):  
Michihiro Osumi ◽  
Daisuke Shimizu ◽  
Yuki Nishi ◽  
Shu Morioka
Keyword(s):  
Electrical Stimulation ◽  
Single Case ◽  
Phantom Limb Pain ◽  
Phantom Limb ◽  
Long Term Effects ◽  
Limb Pain ◽  
Short Term ◽  
Analgesic Effects ◽  
Stimulation Of

Background: Patients with brachial plexus avulsion (BPA) usually experience phantom sensations and phantom limb pain (PLP) in the deafferented limb. It has been suggested that evoking the sensation of touch in the deafferented limb by stimulating referred sensation areas (RSAs) on the cheek or shoulder might alleviate PLP. However, feasible rehabilitation techniques using this approach have not been reported. Objective: The present study sought to examine the analgesic effects of simple electrical stimulation of RSAs in BPA patients with PLP. Methods: Study 1: Electrical stimulation of RSAs for 60 minutes was conducted for six BPA patients suffering from PLP to examine short-term analgesic effects. Study 2: A single case design experiment was conducted with two BPA patients to investigate whether electrical stimulation of RSAs was more effective for alleviating PLP than control electrical stimulation (electrical stimulation of sites on side opposite to the RSAs), and to elucidate the long-term effects of electrical stimulation of RSAs. Results: Study 1: Electrical stimulation of RSAs evoked phantom touch sensations in the deafferented limb, and significantly alleviated PLP (p <  0.05). Study 2: PLP was alleviated more after electrical stimulation on RSAs compared with control electrical stimulation (p <  0.05). However, the analgesic effects of electrical stimulation on RSAs were observed only in the short term, not in the long term (p >  0.05). Conclusions: Electrical stimulation of RSAs not only evoked phantom touch sensation but also alleviated PLP in the short term. The results indicate that electrical stimulation of RSAs may provide a useful practical rehabilitation technique for PLP. Future studies will be required to clarify the mechanisms underlying immediate PLP alleviation via electrical stimulation of RSAs.

scholarly journals Biofilm Lithography enables high-resolution cell patterning via optogenetic adhesin expression

2018 ◽  
Vol 115 (14) ◽  
pp. 3698-3703 ◽  
Author(s):  
Xiaofan Jin ◽  
Ingmar H. Riedel-Kruse
Keyword(s):  
Escherichia Coli ◽  
Cell Patterning ◽  
Biophysical Model ◽  
Microbial Consortia ◽  
Bacterial Biofilms ◽  
Surface Pretreatment ◽  
Resolution Cell ◽  
Stimulation Of

Bacterial biofilms represent a promising opportunity for engineering of microbial communities. However, our ability to control spatial structure in biofilms remains limited. Here we engineerEscherichia coliwith a light-activated transcriptional promoter (pDawn) to optically regulate expression of an adhesin gene (Ag43). When illuminated with patterned blue light, long-term viable biofilms with spatial resolution down to 25 μm can be formed on a variety of substrates and inside enclosed culture chambers without the need for surface pretreatment. A biophysical model suggests that the patterning mechanism involves stimulation of transiently surface-adsorbed cells, lending evidence to a previously proposed role of adhesin expression during natural biofilm maturation. Overall, this tool—termed “Biofilm Lithography”—has distinct advantages over existing cell-depositing/patterning methods and provides the ability to grow structured biofilms, with applications toward an improved understanding of natural biofilm communities, as well as the engineering of living biomaterials and bottom–up approaches to microbial consortia design.

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