Questions related to Brain Stimulation
In a recent study published in the journal "Brain Stimulation," researchers found that transcranial direct current stimulation (TDCS) applied to the prefrontal cortex of the brain can help reduce symptoms of depression in people with mild to moderate depression. In the study, participants received TDCS for two weeks, five days a week, for 20 minutes each session. Results showed that participants who received TDCS had greater reductions in depression symptoms than participants who received a placebo.
However, other studies have shown that the effectiveness of TDCS for treating depression is limited. In a recent study published in the journal "The Lancet Psychiatry," researchers found that TDCS applied to the prefrontal cortex did not produce any difference in depression symptoms between participants who received TDCS and participants who received a placebo.
Greetings all, I am a fifth-year medical student, and currently trying to find a thesis topic. After medical school, I would like to pursue a career in neurosurgery, and therefore, I would preferably welcome suggestions within this discipline. I have conducted my research, and I have formulated a list of areas I would like to explore further. This includes : Implications of deep brain stimulation within neurosurgery A collaborative approach to neurosurgery involving interventional radiologists Having listed topics I am keen to conduct my thesis on, I would be grateful if anyone could suggest particular questions surrounding these. Although I gravitate toward these topics I am open to any suggestions in regard to good questions for my thesis.
There's a weird issue. I have a stim box, which has 2 entrances, one called "act.", and another one - "ref". So if I plug a bipolar electrode in it, so 1 electrode goes to "act." and another to "ref", I see bubbling on only one tip, instead of seeing it on both. If I exchange places, where electrodes connect, I see bubbling on another tip. As I know, it should not be so.
So, do you know, what's the problem here?
I am looking forward to getting a TMS unit to study the human visual cortex. In addition to a single pulse, I will routinely use cTBS. I am debating between magventure and magstim. I've used the magventure with brainsight during my postdoctoral research and am comfortable with it. But this recent Brain Stim paper (attached) biases me towards the magstim.
Any thoughts from the TMS experts on RG?
What are different coil shapes used in Transcranial Magnetic Stimulation? What are their differences (in induced current)? Do they have different applications?
I have used TNS & TMS & TACS systems which resulted in the patients awakening.TDCS was a bit effective but even this caused the patient to wake up after some time .
Quite a few published researchers are using Amrex branded sponge electrodes with banana jack connections for 1x1 low resolution tDCS. We have attempted to use them & have encountered several problems including one serious safety problem.
The electrode in question is a 3" by 3" square non-conductive rubber frame containing conductive wire mesh overlaid with a removable coarse kitchen-type sponge that protrudes out of a 2" by 2" aperture when soaked in saline. The rubber frame is stiff & does not conform well to the curvature of the cranium, especially with smaller subjects. This in turn results in difficulty placing it accurately & reproducibly & also in making good & uniform electrical contact. Though the maximum contact area of the sponge on the scalp is ideally 4 in² (25 cm²), in practice it is considerably less & variable with only a central area of contact which can be approximated as a circular disc inscribed within the 2" by 2" square aperture. This leads in turn to the most serious problem:
Injected current levels up to 2.0 mA are routine in tDCS research. The research community generally accepts a current density limit of .08 mA/cm² for the safety of the subject's skin in contact with the electrode & also to minimize potential damage to the underlying brain tissue. Even if the 2" by 2" sponge made perfect contact with the skin, at the 2.0 mA injected current level the current density limit is reached, exactly, as bulk current density = current / cross-sectional contact area = 2.0 mA / 25 cm² = .08 mA/cm². But these electrodes do not make perfect contact even when the they are secured tightly because of the rigid frames enclosing the sponges. So the contact area is rather less, resulting in the denominator being smaller and the current density necessarily exceeding the safety limit. Even at somewhat lower levels of injected current, taking the variable contact area of the sponges into account, the current density could easily exceed the safety limit. Furthermore, this is a very coarse bulk analysis. Taking nonhomogeneity, edge & corner effects into account, local areas of unacceptably high current density are unavoidable & can be demonstrated convincibly with a more sophisticated analysis (one using finite element methods for example).
Yet another practical problem with these electrodes is they have a strong & pungent odor which research subjects find objectionable, penetrates their hair & endures on the electrodes even after successive washings. If one electrode is placed supraorbitally, as is a common position in tDCS, the obnoxious smell in close proximity to the subject's nose even has the potential to affect the outcome of the experiment because it induces stress & stress-related neurological activity that has the potential to confound results.
These areas were stimulated in mice in a work by Moshel et al (2005) and I would like to understand where the corresponding areas are exactly situated in human.
I am currently testing for my undergraduate dissertation looking at TDCS . I was wondering if what was done/thought/spoken about during the stimulation would change the effect of the TDCS at all?
In a study looking at effects ofTDCS delivered at rest, would having a programme for the duration of stimulation (20 minutes) be a useful means of control?
Any advice or relevant literature suggestions would be greatly appreciated
I'm planning to apply tACS on the scalp in corrispondence of two different cortical areas by using a multi-channel device (Enobio/Starstim, neuroelectrics) . Thus, I will use three electrodes, two "active" and one "return", but I'm wondering whether the value of the current intensity might be devided between the two "active" electrodes. For example, is 2mA of amplitude splitted in 1mA for active electrode 1 and 1mA for active electrode 2.?
May you suggest any work where I could find information about this issue?
Thank you in advance for any answer you may provide.
With the 1.27mm diameter of DBS electrodes often leading to the development of scar tissue, and evidence that electrodes with diameters near the size of neurons, approximately 30 microns, are less likely to induce such scaring, can stimulating electrodes of that size or smaller be expected to perform as well as current DBS electrodes? Is there a minimum optimal diameter for neural stimulating electrodes?
I am a PhD student and I want to design a stimulator for brain application. but I don't know how to start. I really need a good reference or someone who be a partner and help me with that. If someone is working on this subject please lets me know. I would appreciate if anybody did it for me.
I try to record fEPSP in submerged patch clamp setup.
But, I can't record fEPSP in the acute slice. I really don't know the reason.
1. For recording, I use HEKA EPC 10 double.
2. All slices incubate in the slice keeping chamber for 1~1.5h at 32 Celsius in ACSF.
3. Components of intra and bath solution : 126 NaCl, 3.5 KCl, 1.25 NaH2PO4, 1.6 CaCl2, 1.2 MgSO4, 10 Glucose, 26 NaHCO3, 5 HEPES (PH= 7.3-7.4, mOsm= 300-310)
4. ACSF at 30 Celsius, perfuse rate is 2ml/min during fEPSP recording .
5. I set Current clamp mode and holding 0pA. And, I use 1~3 mohm recording electrode.
6. To record fEPSP, I tried to inject from minimum to maximum level of stimulation through simulator I have. Nevertheless, I can't detected fEPSP.
7. In addition, it was confirmed that EPSC and LTP were induced well in the same slice.
8. Before fEPSP was detected once in organotypic culture.
Each picture shows patch clamp setup about submerge state, average distance between bipolar simulator and recording electrode(100~200um), fEPSP in organotypic culture.
1. Is there anything I missed from my protocol to measure fEPSP?
2. fEPSP recorded from organotypic culture look like fIPSP. What's the reason?
Hello, everyone. I am trying to find a method which can monitor temperature changes in brain caused by brain stimulation. Could you help me to find a review paper about it or send me several publications. Many thanks
Does Deep Brain Stimulation work on the Amygdala itself or on connection between amygdala and medial Prefrontal Cortex too?
Perhaps you could help me find answers to several questions on the neural organization of alphabet and number recitation:
1. Could recitation of numbers and letters rely on phonological long-term memory without accessing lexical information? Alternatively, could lexical information be accessed only for numbers (since they are words) but not letters (that are not words)?
2. Several neuroimaging studies (including clinical reports) have shown a dissociation between letter and number sequencing (recitation, reading and writing). Why do you think this is the case?
3. A patient could not recite the alphabet but could sing it upon electrical brain stimulation. Any suggestions why this happened?
Help with any of the questions will be greatly appreciated!
tDCS and tACS are forms of neurostimulation that delivered via electrodes on the head and have therapeutic effects.
I want to know which one has a longer-lasting effect.
There are a lot of invasive technologies in use today that are used to stimulate organs, the nervous system, the brain, and pain receptors in the body.
One example, would be a device that stimulates the vagus nerve, relieving arthritis pain. https://blog.applysci.com/?p=3170
Where can I source a list of the frequencies, pulse duration, and voltages used in such applications?
Feeding knowledge directly into your brain, just like in sci-fi classic The Matrix, by a simulator which can feed information directly into a person’s brain and teach them new skills in a shorter amount of time, comparing it to “life imitating art”. I think inventing a devive that feed skills directly into a person’s brain is little far from believing . But what if build a device that stimulates some parts of a person's brain that related to the new skill that person is learning .so ,that person by using such a device could learn that new skill in very shorter time.
In most diseases with no cure or long-term treatment, there are different shortages in the body from our brain's function to lack of Nutrients. Maybe we can stimulate particular parts of patient's brain to act differently and control the body to fight better with illness.
Can haloperidol induced catalepsy model be used as parkinson's disease model to study Deep brain stimulation (DBS) or 6-hydroxy dopamine ( 6-OHDA) bilateral lesioned model is more relevant? Are there any models which is better than Haloperidol induced catalepsy model or 6-OHDA model, if yes which one is it and why. Thanks in advance for kind help.
I have been doing research on this topic, but have found little empirical evidence supporting or denying its effects on brainwaves. I am currently in the process of designing experiments to see if these frequencies affect mood or have any noticeable result, but I need more resources on what has been proven or disproven about them and to what degree they are placebo.
Is there a way of single pulse electrical stimulation through DBS electrodes after they have already attached to the pulse generator? or, the only way is to stimulate through the externalized electrode immediately after surgical operation in the period before the electrode will get attached to the pulse generator? are there any pulse generators capable of doing single pulse? Medtronic ones are able to produce 3Hz stimulation as the lowest stimulation frequency.
Hi , As we know the bioelectric scientists can stimulate different kinds of senses like perception and vision in patients and also can eliminate senses such as pain and pruritus.
Now my question is: does it possible for scientists to make stimulations in CNS of patients with nightmares in order to cure their nightmare and making desired dreams?
thanks for you attention,
I am trying to investigate learning and memory consolidation over sleep/wake using brain stimulation. Multiple studies have used the paired-association list learning task in the context of sleep; however, only one study has used tDCS and Sleep with this paradigm. Unfortunately, this study made use of German words. Can someone recommend an English database for me to design this experiment?
Dear tACS community, dear physicists and electrical engineers
I would be very grateful if somebody with the appropriate training could please clarify how to calculate the current density under the stimulation electrode for an alternating current? Based on the standard set by tDCS research (direct current stimulation), some researchers variably divide either the half peak maximum amplitude or the peak-to-peak amplitude by the electrode area, while others say that this measure is inappropriate for AC currents. What is the correct measure that relates injected current and electrode surface area?
Like most researchers in the tDCS community, I'm looking to induce persistent LTP-like effects.
The current literature is informative insofar as highlighting that multiple sessions of tDCS appear to enhance the strength and prolong the duration of resulting after-effects. The time at which repeat stimulation is administered also appears to be crucial but as yet there is little-to-no consensus on the most optimal parameters to use, including appropriate inter-stimulation-intervals. More recently, there seems to be a suggestion that implementing within-session intervals instead of continuous stimulation could be the way to go, however, the related studies only cover single sessions and don't comment on the frequency at which subsequent sessions of stimulation should be delivered.
Does anyone have any experience of attempting to induce longer lasting modulations - successful or otherwise? I'd appreciate advice on what to trial, what to avoid and whether you've noted differences between target populations (healthy/clinical, young/old etc) with regard to the parameters that show the most potential.
Thanks in advance!
I was looking for some tDCS stimulation software and fortunately found COMETS (http://cone.hanyang.ac.kr/BioEST/Kor/Comets.html) . I would like to dig bit deep into it and started to examine the output file POTENT.OUT and other files. Could someone please help me with the following questions.
1) The file POTENT.OUT has voxels and associated with a number, I am presuming that value as current. Am I correct here or is it Electric field, if so what are the units for that value?
2) I happen to open POTENT.OUT file in Notepad and found 13,194 voxels and with corresponding current in each of them( example 1 0.00003467) which has 3D co-ordinates associated with those 13,194 voxels in xyz.dat file. The problem I am facing is , I couldn’t find out the boundaries associated with these voxels, like voxel number 1-1000 belong to frontal lobe, 10000-5000 belong to Parietal Lobe etc.
3) I used MESH VIEWER to view .PLY files, the only thing I can see is brain model but not the stimulated region in it.
4) I would like to build my own head models, so all I need to do is get fMRI Images and get them into CURRY 7 and create boundary conditions. Is that all I need to do or any other software I need to use other than this?
Any help is very much appreciated.
Many thanks in advance.
I have a budget of ~20.000$ and I would like to buy a system to record and stimulate (electrical micro-stimulation) from laminar electrode (i.e. Plexon U-probe http://www.plexon.com/products/plexon-u-probe). I am working with behaving macaques. At the moment I am not interested in a perfect single-neuron spike-shape isolation.
I would be very grateful if you could suggest me any item/company.
I am currently interested in a research on the application of deep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM) for patients with dementia. Several studies in animal confirmed that the effect of low frequency stimulation (LFS) of cholinergic neurons in the NBM is able to induce cortical cholinergic release, which results functionally to cognitive improvement (Kurosawa et al, 1989). Human studies have also found cognitive improvement to some extent by LFS of the NBM (See studies by Freund et al, 2009 and Kuhn et al, 2015). Given the recent finding that the DBS mechanism of action is not merely about high frequency stimulation (HFS) inhibits neurons and LDS excites neurons (in fact, both stimulation settings excite neurons, for rev. see Montgomery, 2010), what would be an explanation that different setting of frequency parameter results in different result of acetylcholine release in the cortex?
I use a saline solution tank and try to apply currents through electrodes in it. My problem is that the properties of the saline solution change with current passing through it and I have to re-prepare the solution. Is there a way around this?
Is there any reliable study about long-term outcomes in young patients (25-35aa) with essential tremor treated with unilateral thalamic lesions or deep brain stimulation? My question is not only about long term tremor and quality of life rating scales but especially about long term cognitive impairment if any.
Transcranial Magnetic Stimulation has brought a lot of hope in the field of non-invasive treatment of Neurological disorders.
As it has picked my interest in the case of Parkinson's Disease, I can't help but wonder how we hope such a specific effect of TMS on PD's motor symptoms. Indeed the basal ganglia circuits is a very complex one and each structure will affect several others in an activating or inhibiting way. So how can we really hope for a specific effect, when we are merely activating a superficial region (that will of course, in turn, activate others, but still, how specific can such an intervention be) ?
There has been some effect I have seen, but, as of now (and I know it is still a young field of investigation), results are mitigated (see Benninger and Hallet review in NeuroRehabilitation, 2015 for a recent comparison of results)
Or maybe will it be more useful in combination with medication ?
Any thoughts ?
I want to do fEPSP recordings on the Shaffer-CA1 pathway in vivo in the middle part of hippocampus in rat. I checked the literature and found conflicting results.
For example, in the work of Doyle et al. (J Neurosci, 1996, vol 16, 418-424) and their later works, the recording electrode was placed closer to the Bregma than the stimulating electrode was (recording electrode: AP -3.0, ML 2.0; stimulating electrode: AP -4, ML 3).
However, in some other works, e.g., Bliss et al. (J Physiol, 1983, 341, pp617-26), it is the stimulating electrode that is closer to the Bregma (stimulating: AP -3.4, ML 3.2; recording: -4.4, ML 3.0). Both claimed that they were stimulating and recording the CA3-to-CA1 pathway. How could they had the exact opposite way of placing the stimulating and recording electrodes when both claimed to stimulate & recording the same pathway? These are just some examples. I found more reports with conflicting coordinates.
I am wondering if anyone has a clearer answer on that, and can tell me the accurate way to place the electrodes on CA1 pathway in rat hippocampus.
My area of research is effect tDCS (Trans-Cranial Direct Current Stimulation) on brain potentials.
I don’t have a good knowledge in tDCS modelling but would like use it a bit in my thesis. As I have already completed 2 years of my PHD I don’t want drift into new field or code the stuff for modelling. I would like to observe how current flows into brain when tDCS is applied. I looked for tDCS modelling software and couldn’t find many in my search. I found one named SPHERES (http://neuralengr.com/spheres/?page_id=17), which doesn’t have human brain model instead have a sphere but can play with parameters (amount of current, electrodes location where tDCS is applied etc).
Could anyone please help me with a simulation software where I can play with parameters like amount of current, electrodes location where tDCS is applied etc. Any help would be really appreciated.
I'm currently doing BDA (biotinylated dextran amine) injections into the motor cortex for anterograde axonal tracing. My BDA is tagged with Alexa 488 and Alexa 564. The biggest issue I'm having at the moment is that my BDA is staining the pia mater of my brain and appears to be going everywhere! I think it's contributing to some of the vessel staining I'm seeing as well.
I've tried varying speeds and amounts of injected BDA. Pulling the needle out slowly, but none of this seems to be really reducing the spillage.
I've attached a picture so you can see the staining all along the edge of the brain.
Has anyone who has done this procedure before encountered this problem?
I'm planning to join a research group that involves Deep Brain Stimulation. So I would like to know how much of MATLAB programming I need to know in order to do any sort of signal analysis that involves Deep brain stimulation. I know the basics of MATLAB as of now. Do I need to certain methods in MATLAB in order to carry out the signal analysis in MATLAB ?
Good morning, I’m doing in vivo electrophysiology in anesthetized mice. I’m recording evoked filed excitatory post synaptic potentials (fEPSP) in the hippocampus CA1 stratum radiatum after the electrical stimulation of ipsilateral CA3 axons. I would like to test other concentric bipolar stimulation electrodes but I don’t have the knowledge necessary to wisely choose a configuration that might fit my needs. Thereby I would like to learn how to choose an electrode (even another that bipolar if it is the case) that might adapt the best for the brain region on which I'm currently experimenting on (which currently is the hippocampus) and perhaps others in a near future. Thank you.
In an episodic memory consolidation experiment there are at least three stages: 1) encoding, 2) reactivation, 3) recall. We want to see how the stimulation during reactivation stage impair memory traces. Is it necessary to ensure that the subject has done a good encoding (accuracy>90%), for example with an "old/new test" after encoding stage? I think this test could affect the results because it's a sort of reactivation.
Electroconvulsive and electromagnetic stimulation are two therapies used in patients with depressive disorder, schizophrenia, mania and others psychiatric problems. Generally, these therapies are employed in patients who didn't have success with psychotropic drugs. The brain chemistry is complex, but some drugs influence the neurotransmitters (dopamine, levodopa, ...). How do physical therapies affect the brain biochemistry? Can anyone indicate some book or paper about subject? I think to develop sensors for diagnosis in this area, but I don't know very much about psychiatric therapies. I would like to study more specifically this problem that affect many people in world.
It’s been known for decades that electrical stimulation of brain increase the extracellular concentration of dopamine significantly and helps to restore some function of the brain specially in movement disorders like Parkinson disease, dystonia etc. Recent past has also revealed that electrical stimulation of the brodmann area 25 or subgenual cingulate in human cortex help in reducing the depression like symptoms in patient suffering from major depressive disorder. Is their information available about the functional mechanism behind the induction of the dopamine and serotonin release by electrical stimulation of the brain? And, is it works for both dopamine and serotonin release differently or it works on the same principle for both? Also is this process of electrical stimulation help or induce the synthesis of the dopamine and serotonin or it just help in release of available neurotransmitters only? If later is the case what’s the intracellular concentration of the dopamine and serotonin after stimulation? I am trying to find out the mechanism about how cells maintains its equilibrium after stimulation which can increase the extracellular concentration of these neurotransmitters significantly in very short span of time and not warranting the long term integrity of cells. Any suggestion or comments would be highly appreciated.
Which is responsible for memory saving mechanism: Neural network of brain or molecular quantum transition in definite locations in brain or selective chemical reactions all over the brain or none of them? How and where does the brain store such a tremendous amount of data? What are read and write mechanism of this data? Is the chemical -base processing dominant or physical -base one?
I know UPDRS is the standard rating for clinical follow up. I am interested in any knowledge about imaging data or other means to quantify disease progression that is independant of clinical evaluation.
Could transcranial magnetic stimulation (TMS) be used to create a new definition if someone is dead or not? And could it play a role in resuscitation (eg. used in conjunction with CPR for a victim of drowning).
It appears our definition of what is dead needs to be redefined. Increased number of victims of drowning, cardiac arrest etc. are being resuscitated after the normal vital signs have gone. In 2011, the medical journal Resuscitation reported the case of a Japanese woman being resuscitated over four hours after being found dead. She later went on to bear children as normal.
Those that have recovered from being "dead" for long times are often able to recount experiences of feeling still conscious while they were medically "dead."
It seems to me that we need a new definition of what dead is. I am thinking that TMS could be used to test if body parts still respond to TMS brain stimulation of a "dead" body. If there is still muscle movement, then it means electrical pathways are still intact and therefore there could be a chance for resuscitation.
I hypothesize that TMS could be used in conjunction with CPR and might help to stimulate resuscitation. Has this idea been considered and has any research carried out?
For example: different people may have a different skin conductance and resistance. It may also not be possible to control the exact amount of saline. Are these differences important or not?
This is related with dopamine innervation. I want to know if it is possible to relate dopaminergic innervation of basal ganglia and sensory motor cortex for arm movements to gait.
It is difficult to generate clean clear crisp images that allow you to visualize DBS stimulating leads and local anatomy, while still staying within the Medtronic/FDA recomended average head coil SARs levels of .1W/Kg.
We are pleased with our pre-surgical targeting sequences, but are having a difficult time modifying the same parameters for post op post implant imaging.
Using a GE 1.5T with Send/Recieve head coil.
FlipAngle TE TR TI SlTh SlSep Nex Bandwidth FOV
Saggital MPRAGE 20 min full 2 0 1 15.63KHz
Axial Oblique T2 N/A 68 2500 2 0 4 15.63KHz 28
Axial T2 Straight N/A 68 5184 2 0 2 20.83KHz 28
Coronal T2 Straight N/A 68 3534 2 0 2 16.67KHz 28
Axial 3D SPGR 30 min full 2 0 1 15.63KHz 26
Axial STIR 40 3000 200 4 Intrlv 3 31.25KHz 26
What are the standard frequency parameters for controlling tremor in Essential Tremor individuals implanted in the VIM? Is it the same high frequency centered around 185Hz, or has good control been obtained with lower frequencies?