Synaptic Plasticity 101: The Story of the AMPA Receptor for the Brain Stimulation Practitioner

Inflammation of the central nervous system can be triggered by endogenous and exogenous stimuli such as local or systemic infection, trauma, and stroke. In addition to neurodegeneration and cell death, alterations in physiological brain functions are often associated with neuroinflammation. Robust experimental evidence has demonstrated that inflammatory cytokines affect the ability of neurons to express plasticity. It has been well-established that inflammation-associated alterations in synaptic plasticity contribute to the development of neuropsychiatric symptoms. Nevertheless, diagnostic approaches and interventional strategies to restore inflammatory deficits in synaptic plasticity are limited. Here, we review recent findings on inflammation-associated alterations in synaptic plasticity and the potential role of the blood–brain interface, i.e., the blood–brain barrier, in modulating synaptic plasticity. Based on recent findings indicating that brain stimulation promotes plasticity and modulates vascular function, we argue that clinically employed non-invasive brain stimulation techniques, such as transcranial magnetic stimulation, could be used for monitoring and modulating inflammation-induced alterations in synaptic plasticity.

Download Full-text

Doxorubicin induces dysregulation of AMPA receptor and impairs hippocampal synaptic plasticity leading to learning and memory deficits

Heliyon ◽

10.1016/j.heliyon.2021.e07456 ◽

2021 ◽

pp. e07456

Author(s):

Ahmad H. Alhowail ◽

Priyanka D. Pinky ◽

Matthew Eggert ◽

Jenna Bloemer ◽

Lauren N. Woodie ◽

...

Keyword(s):

Synaptic Plasticity ◽

Learning And Memory ◽

Ampa Receptor ◽

Memory Deficits ◽

Hippocampal Synaptic Plasticity ◽

Learning And Memory Deficits

Download Full-text

Novel Heat-Mitigating Chip-on-Probe for Brain Stimulation Behavior Experiments

Sensors ◽

10.3390/s20247334 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7334

Author(s):

Seongwoog Oh ◽

Jungsuek Oh

Keyword(s):

Brain Stimulation ◽

Heat Sink ◽

Transmission Loss ◽

Maximum Output Power ◽

Circuit Board ◽

Oxide Semiconductor ◽

Normal Operation ◽

Cmos Process ◽

Maximum Output ◽

The Brain

This paper proposes a novel design for a chip-on-probe with the aim of overcoming the heat dissipation effect during brain stimulations using modulated microwave signals. The temperature of the stimulus chip during normal operation is generally 40 °C–60 °C, which is sufficient to cause unintended temperature effects during stimulation. This effect is particularly fatal in brain stimulation applications that require repeated stimulation. This paper proposes, for the first time, a topology that vertically separates the stimulus chip generating the stimulus signal and the probe delivering the signal into the brain to suppress the heat transfer while simultaneously minimizing the radio frequency (RF) transmission loss. As the proposed chip-on-probe should be attached to the head of a small animal, an auxiliary board with a heat sink was carefully designed considering the weight that does not affect the behavior experiment. When the transition structures are properly designed, a heat sink can be mounted to maximize the cooling effect, reducing the temperature by more than 13 °C in a simulation when the heat generated by the chip is transferred to the brain, while the transition from the chip to the probe experiences a loss of 1.2 dB. Finally, the effectiveness of the proposed design is demonstrated by fabricating a chip with the 0.28 μm silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) process and a probe with a RT6010 printed-circuit board (PCB), showing a temperature reduction of 49.8 °C with a maximum output power of 11 dBm. In the proposed chip-on-probe device, the temperature formed in the area in contact with the brain is measured at 31.1 °C.

Download Full-text

Brain shift: an error factor during implantation of deep brain stimulation electrodes

Journal of Neurosurgery ◽

10.3171/jns-07/11/0989 ◽

2007 ◽

Vol 107 (5) ◽

pp. 989-997 ◽

Cited By ~ 102

Author(s):

Yasushi Miyagi ◽

Fumio Shima ◽

Tomio Sasaki

Keyword(s):

Deep Brain Stimulation ◽

Brain Stimulation ◽

Brain Shift ◽

Mr Images ◽

Implanted Electrodes ◽

Error Factor ◽

Bilateral Surgery ◽

Second Procedure ◽

The Brain ◽

Deep Brain

Object The goal of this study was to focus on the tendency of brain shift during stereotactic neurosurgery and the shift's impact on the unilateral and bilateral implantation of electrodes for deep brain stimulation (DBS). Methods Eight unilateral and 10 bilateral DBS electrodes at 10 nuclei ventrales intermedii and 18 subthalamic nuclei were implanted in patients at Kaizuka Hospital with the aid of magnetic resonance (MR) imaging–guided and microelectrode-guided methods. Brain shift was assessed as changes in the 3D coordinates of the anterior and posterior commissures (AC and PC) with MR images before and immediately after the implantation surgery. The positions of the implanted electrodes, based on the midcommissural point and AC–PC line, were measured both on x-ray films (virtual position) during surgery and the postoperative MR images (actual position) obtained on the 7th day postoperatively. Results Contralateral and posterior shift of the AC and PC were the characteristics of unilateral and bilateral procedures, respectively. The authors suggest the following. 1) The first unilateral procedure elicits a unilateral air invasion, resulting in a contralateral brain shift. 2) During the second procedure in the bilateral surgery, the contralateral shift is reset to the midline and, at the same time, the anteroposterior support by the contralateral hemisphere against gravity is lost due to a bilateral air invasion, resulting in a significant posterior (caudal) shift. Conclusions To note the tendency of the brain to shift is very important for accurate implantation of a DBS electrode or high frequency thermocoagulation, as well as for the prediction of therapeutic and adverse effects of stereotactic surgery.

Download Full-text

Stress hormones and AMPA receptor trafficking in synaptic plasticity and memory

Nature Reviews Neuroscience ◽

10.1038/nrn2913 ◽

2010 ◽

Vol 11 (10) ◽

pp. 675-681 ◽

Cited By ~ 112

Author(s):

Harmen J. Krugers ◽

Casper C. Hoogenraad ◽

Laurent Groc

Keyword(s):

Synaptic Plasticity ◽

Ampa Receptor ◽

Stress Hormones ◽

Receptor Trafficking ◽

Ampa Receptor Trafficking

Download Full-text

Brain stimulation used as biofeedback in neuronal activation of the temporal lobe area in autistic children

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20160092 ◽

2016 ◽

Vol 74 (8) ◽

pp. 632-637 ◽

Cited By ~ 2

Author(s):

Vernon Furtado da Silva ◽

Mauricio Rocha Calomeni ◽

Rodolfo Alkmim Moreira Nunes ◽

Carlos Elias Pimentel ◽

Gabriela Paes Martins ◽

...

Keyword(s):

Data Collection ◽

Brain Stimulation ◽

Mirror Neurons ◽

Brain Area ◽

Control Group ◽

Autistic Children ◽

Emotional Stimuli ◽

The One ◽

The Brain ◽

Data Collection Procedure

ABSTRACT This study focused upon the functional capacity of mirror neurons in autistic children. 30 individuals, 10 carriers of the autistic syndrome (GCA), 10 with intellectual impairments (GDI), and 10 non-autistics (GCN) had registered eletroencephalogram from the brain area theoretically related to mirror neurons. Data collection procedure occurred prior to brain stimulation and after the stimulation session. During the second session, participants had to alternately process figures evoking neutral, happy, and/or sorrowful feelings. Results proved that, for all groups, the stimulation process in fact produced additional activation in the neural area under study. The level of activation was related to the format of emotional stimuli and the likelihood of boosting such stimuli. Since the increase of activation occurred in a model similar to the one observed for the control group, we may suggest that the difficulty people with autism have at expressing emotions is not due to nonexistence of mirror neurons.

Download Full-text

Accuracy of Magnetic Resonance Imaging–Directed Frame-Based Stereotaxis

Operative Neurosurgery ◽

10.1227/neu.0b013e3182320bd6 ◽

2011 ◽

Vol 70 (suppl_1) ◽

pp. ons114-ons124 ◽

Cited By ~ 1

Author(s):

Nova B. Thani ◽

Arul Bala ◽

Christopher R. P. Lind

Keyword(s):

Deep Brain Stimulation ◽

Magnetic Resonance ◽

Brain Stimulation ◽

Entry Point ◽

Mean Deviation ◽

Guide Tube ◽

3 Dimensional ◽

The Mean ◽

The Brain ◽

Deep Brain

Abstract BACKGROUND: Accurate placement of a probe to the deep regions of the brain is an important part of neurosurgery. In the modern era, magnetic resonance image (MRI)-based target planning with frame-based stereotaxis is the most common technique. OBJECTIVE: To quantify the inaccuracy in MRI-guided frame-based stereotaxis and to assess the relative contributions of frame movements and MRI distortion. METHODS: The MRI-directed implantable guide-tube technique was used to place carbothane stylettes before implantation of the deep brain stimulation electrodes. The coordinates of target, dural entry point, and other brain landmarks were compared between preoperative and intraoperative MRIs to determine the inaccuracy. RESULTS: The mean 3-dimensional inaccuracy of the stylette at the target was 1.8 mm (95% confidence interval [CI], 1.5-2.1. In deep brain stimulation surgery, the accuracy in the x and y (axial) planes is important; the mean axial inaccuracy was 1.4 mm (95% CI, 1.1-1.8). The maximal mean deviation of the head frame compared with brain over 24.1 ± 1.8 hours was 0.9 mm (95% CI, 0.5-1.1). The mean 3-dimensional inaccuracy of the dural entry point of the stylette was 1.8 mm (95% CI, 1.5-2.1), which is identical to that of the target. CONCLUSION: Stylette positions did deviate from the plan, albeit by 1.4 mm in the axial plane and 1.8 mm in 3-dimensional space. There was no difference between the accuracies at the dura and the target approximately 70 mm deep in the brain, suggesting potential feasibility for accurate planning along the whole trajectory.

Download Full-text

A Method for Chronically Implanting Stimulating Electrodes into the Brains of Locusts, and some Results of Stimulation

Journal of Experimental Biology ◽

10.1242/jeb.40.2.271 ◽

1963 ◽

Vol 40 (2) ◽

pp. 271-284

Author(s):

C. H. FRASER ROWELL

Keyword(s):

Stainless Steel ◽

Brain Stimulation ◽

Sexual Behaviour ◽

Foraging Behaviour ◽

Stimulating Electrodes ◽

The Brain ◽

Antennal Movement ◽

Steel Electrodes

1. Methods are described for implanting permanent stainless-steel electrodes into the brains of locusts, for stimulating the brain under near-normal conditions, and for localizing the electrode subsequently. 2. Threshold currents measured under these conditions are lower than those required in acute preparations, or if the animal is restrained. 3. The results of stimulation are described for four common aspects of behaviour. These are antennal movement, locomotion, feeding and sexual behaviour. 4. The effect of stimulation on antennal and locomotory movements largely confirms previous work on crickets. 5. Feeding and foraging behaviour, which is a very common result, is shown to be almost completely determined by peripheral stimuli at the time of brain stimulation. The role of the latter is permissive or disinhibitory rather than causal or excitatory. 6. Integrated sexual behaviour is occasionally inhibited, but never elicited, by stimulation. This contrasts with observations on crickets, and its implications are discussed.

Download Full-text