scholarly journals Stimulation of [ 35 S]GTPγS binding by GABA B receptor agonists and positive modulators in different mouse brain regions

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Tushar Advani ◽  
Julie G Hensler ◽  
Kejun Cheng ◽  
Kenner C Rice ◽  
Wouter Koek
Keyword(s):  
Mouse Brain ◽  
Brain Regions ◽  
Receptor Agonists ◽  
Gtpγs Binding ◽  
Stimulation Of

scholarly journals Incerto-thalamic modulation of fear via GABA and dopamine

2021 ◽  
Author(s):  
Archana Venkataraman ◽  
Sarah C. Hunter ◽  
Maria Dhinojwala ◽  
Diana Ghebrezadik ◽  
JiDong Guo ◽  
...  
Keyword(s):  
Brain Regions ◽  
Zona Incerta ◽  
Dependent Manner ◽  
Post Traumatic Stress ◽  
Functional Roles ◽  
Functional Connections ◽  
Optogenetic Stimulation ◽  
Fear Generalization ◽  
Stimulation Of

AbstractFear generalization and deficits in extinction learning are debilitating dimensions of Post-Traumatic Stress Disorder (PTSD). Most understanding of the neurobiology underlying these dimensions comes from studies of cortical and limbic brain regions. While thalamic and subthalamic regions have been implicated in modulating fear, the potential for incerto-thalamic pathways to suppress fear generalization and rescue deficits in extinction recall remains unexplored. We first used patch-clamp electrophysiology to examine functional connections between the subthalamic zona incerta and thalamic reuniens (RE). Optogenetic stimulation of GABAergic ZI → RE cell terminals in vitro induced inhibitory post-synaptic currents (IPSCs) in the RE. We then combined high-intensity discriminative auditory fear conditioning with cell-type-specific and projection-specific optogenetics in mice to assess functional roles of GABAergic ZI → RE cell projections in modulating fear generalization and extinction recall. In addition, we used a similar approach to test the possibility of fear generalization and extinction recall being modulated by a smaller subset of GABAergic ZI → RE cells, the A13 dopaminergic cell population. Optogenetic stimulation of GABAergic ZI → RE cell terminals attenuated fear generalization and enhanced extinction recall. In contrast, optogenetic stimulation of dopaminergic ZI → RE cell terminals had no effect on fear generalization but enhanced extinction recall in a dopamine receptor D1-dependent manner. Our findings shed new light on the neuroanatomy and neurochemistry of ZI-located cells that contribute to adaptive fear by increasing the precision and extinction of learned associations. In so doing, these data reveal novel neuroanatomical substrates that could be therapeutically targeted for treatment of PTSD.

Learning Deficits Accompanied by Microglial Proliferation After the Long-Term Post-Injection of Alzheimer’s Disease Brain Extract in Mouse Brains

2021 ◽  
Vol 79 (4) ◽  
pp. 1701-1711
Author(s):  
Tetsuo Hayashi ◽  
Shotaro Shimonaka ◽  
Montasir Elahi ◽  
Shin-Ei Matsumoto ◽  
Koichi Ishiguro ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Brain ◽  
Functional Decline ◽  
Brain Regions ◽  
Insoluble Fraction ◽  
Brain Extract ◽  
Post Injection ◽  
Learning Deficits

Background: Human tauopathy brain injections into the mouse brain induce the development of tau aggregates, which spread to functionally connected brain regions; however, the features of this neurotoxicity remain unclear. One reason may be short observational periods because previous studies mostly used mutated-tau transgenic mice and needed to complete the study before these mice developed neurofibrillary tangles. Objective: To examine whether long-term incubation of Alzheimer’s disease (AD) brain in the mouse brain cause functional decline. Methods: We herein used Tg601 mice, which overexpress wild-type human tau, and non-transgenic littermates (NTg) and injected an insoluble fraction of the AD brain into the unilateral hippocampus. Results: After a long-term (17–19 months) post-injection, mice exhibited learning deficits detected by the Barnes maze test. Aggregated tau pathology in the bilateral hippocampus was more prominent in Tg601 mice than in NTg mice. No significant changes were observed in the number of Neu-N positive cells or astrocytes in the hippocampus, whereas that of Iba-I-positive microglia increased after the AD brain injection. Conclusion: These results potentially implicate tau propagation in functional decline and indicate that long-term changes in non-mutated tau mice may reflect human pathological conditions.

scholarly journals Transcriptome Atlases of Mouse Brain Reveals Differential Expression Across Brain Regions and Genetic Backgrounds

2012 ◽  
Vol 2 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Wei Sun ◽  
Seunggeun Lee ◽  
Vasyl Zhabotynsky ◽  
Fei Zou ◽  
Fred A. Wright ◽  
...  
Keyword(s):  
Differential Expression ◽  
Mouse Brain ◽  
Brain Regions

scholarly journals The Connectivity Index: An Effective Metric for Grading Epileptogenicity

2019 ◽  
Author(s):  
Qi Yan ◽  
Nicolas Gaspard ◽  
Hitten P Zaveri ◽  
Hal Blumenfeld ◽  
Lawrence J. Hirsch ◽  
...  
Keyword(s):  
Average Distance ◽  
Single Pulse ◽  
Brain Regions ◽  
Control Site ◽  
Connectivity Index ◽  
Evoked Responses ◽  
Seizure Onset ◽  
Seizure Onset Zone ◽  
Site Of Stimulation ◽  
Stimulation Of

AbstractObjectiveTo investigate the performance of a metric of functional connectivity to classify and grade the excitability of brain regions based on evoked potentials to single pulse electrical stimulation (SPES).MethodsPatients who received 1-Hz frequency stimulation between 2003 and 2014 at Yale at prospectively selected contacts were included. The stimulated contacts were classified as seizure onset zone (SOZ), highly irritative zone (IZp) or control. Response contacts were classified as seizure onset zone (SOZ), active interictal (IZp), quiet or other. The normalized number of responses was defined as the number of contacts with any evoked responses divided by the total number of recorded contacts, and the normalized distance is the ratio of the average distance between the site of stimulation and sites of evoked responses to the average distances between the site of stimulation and all other recording contacts. A new metric we labeled the connectivity index (CI) is defined as the product of the two values.Results57 stimulation-sessions in 22-patients were analyzed. The connectivity index (CI) of the SOZ was higher than control (median CI of 0.74 vs. 0.16, p = 0.0002). The evoked responses after stimulation of SOZ were seen at further distance compared to control (median normalized distance 0.96 vs. 0.62, p = 0.0005). It was 1.8 times more likely to record a response at SOZ than in non-epileptic contacts after stimulation of a control site. Habitual seizures were triggered in 27% of patients and 35 % of SOZ contacts (median stimulation intensity 4 mA) but in none of the control or IZp contacts. Non-SOZ contacts in multifocal or poor surgical outcome cases had a higher CI than non-SOZ contacts in those with localizable onsets (medians CI of 0.5 vs. 0.12, p = 0.04). There was a correlation between the stimulation current intensity and the normalized number of evoked responses (r = + 0.49, p 0.01) but not with distance (r = + 0.1, p 0.64)ConclusionsWe found enhanced connectivity when stimulating the SOZ compared to stimulating control contacts; responses were more distant as well. Habitual auras and seizures provoked by SPES were highly predictive of brain sites involved in seizure generation.

scholarly journals Transcranial magnetic stimulation of mouse brain using high-resolution anatomical models

2014 ◽  
Vol 115 (17) ◽  
pp. 17B303 ◽  
Author(s):  
L. J. Crowther ◽  
R. L. Hadimani ◽  
A. G. Kanthasamy ◽  
D. C. Jiles
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
High Resolution ◽  
Mouse Brain ◽  
Magnetic Stimulation ◽  
Anatomical Models ◽  
Stimulation Of

scholarly journals Optogenetic spatial and temporal control of cortical circuits on a columnar scale

2016 ◽  
Vol 115 (2) ◽  
pp. 1043-1062 ◽  
Author(s):  
Arani Roy ◽  
Jason J. Osik ◽  
Neil J. Ritter ◽  
Shen Wang ◽  
James T. Shaw ◽  
...  
Keyword(s):  
Visual Stimulation ◽  
Liquid Crystal Display ◽  
Brain Regions ◽  
Cortical Activation ◽  
Mammalian Brain ◽  
Optogenetic Stimulation ◽  
Brain Surface ◽  
Stimulation System ◽  
Circuit Function ◽  
Stimulation Of

Many circuits in the mammalian brain are organized in a topographic or columnar manner. These circuits could be activated—in ways that reveal circuit function or restore function after disease—by an artificial stimulation system that is capable of independently driving local groups of neurons. Here we present a simple custom microscope called ProjectorScope 1 that incorporates off-the-shelf parts and a liquid crystal display (LCD) projector to stimulate surface brain regions that express channelrhodopsin-2 (ChR2). In principle, local optogenetic stimulation of the brain surface with optical projection systems might not produce local activation of a highly interconnected network like the cortex, because of potential stimulation of axons of passage or extended dendritic trees. However, here we demonstrate that the combination of virally mediated ChR2 expression levels and the light intensity of ProjectorScope 1 is capable of producing local spatial activation with a resolution of ∼200–300 μm. We use the system to examine the role of cortical activity in the experience-dependent emergence of motion selectivity in immature ferret visual cortex. We find that optogenetic cortical activation alone—without visual stimulation—is sufficient to produce increases in motion selectivity, suggesting the presence of a sharpening mechanism that does not require precise spatiotemporal activation of the visual system. These results demonstrate that optogenetic stimulation can sculpt the developing brain.

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