Tamara K Berdyyeva

Janssen Research & Development, LLC | JANSSEN · NS Biomarkers

Purpose The P2X7 receptor, an adenosine triphosphate (ATP)-gated purinoreceptor, has emerged as one of the key players in neuroinflammatory processes. Therefore, developing a positron emission tomography (PET) tracer for imaging of P2X7 receptors in vivo presents a promising approach to diagnose, monitor, and study neuroinflammation in a variety of...

Imaging neuronal activity in awake behaving mice with miniature fluorescence microscopes requires the implementation of a variety of procedures. Surgeries are performed to gain access to the cell population of interest and to implant microscope components. After a recovery period, mice are trained to exhibit a desired behavior. Finally, neuronal ac...

Prolonged exposure to abnormally high calcium concentrations is thought to be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized calcium activity during seizures in the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographi...

Mean normalized fluorescence intensities during the first identifiable wave were aligned with respect to peak time and plotted across time (red and blue, NMDA treatment; green, PTZ treatment). Same scale as Figure 4F.

Assessment of seizure severity in different groups of mice. A seizure stage 3 or higher (“Materials and methods, Seizure assessment”) was classified as a convulsive motor seizure (CMS). Seizure latency was defined as the time period (in minutes) required to reach CMS. No significant differences were found between mice implanted with telemetric devi...

Overview of Stereotypical Epileptiform Motifs. Videos of the epileptiform motifs are presented in real-time. Changes in calcium sensor fluorescence are presented on a log-contrast scale in order to visualize the changes within individual cells during the flashing and wave epileptiform patterns, which differed in intensity by orders of magnitude. Co...

Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an...

The orexin/hypocretin neuropeptides are produced by a cluster of neurons within the lateral posterior hypothalamus and participate in neuronal regulation by activating their receptors (OX1 and OX2 receptors). The orexin system projects widely through the brain and functions as an interface between multiple regulatory systems including wakefulness,...

Neurons in the Supplementary Eye Field (SEF) of the macaque monkey exhibit rank selectivity, firing differentially as a function of the phase attained during the performance of a task requiring the execution of saccades to a series of objects in fixed order. The activity of these neurons is commonly thought to represent ordinal position in the serv...

Neurons in several areas of the monkey frontal cortex exhibit rank selectivity, firing differentially as a function of the stage attained during the performance of a serial order task. The activity of these neurons is commonly thought to represent ordinal position within the trial. However, they might also be sensitive to factors correlated with or...

Neurons in several areas of monkey frontal cortex exhibit ordinal position (rank) selectivity during the performance of serial order tasks. It has been unclear whether rank selectivity or the dependence of rank selectivity on task context varies across the areas of frontal cortex. To resolve this issue, we recorded from neurons in the supplementary...

Major scientific breakthroughs often stem from key technological advances. For example, the development of gene targeting techniques has revolutionized biology by providing a set of tools that can be used to visualize, measure, and systematically change the spatiotemporal processes that define living systems. Within neurobiology, these techniques h...

When correlation is measured in the presence of noise, its value is decreased. In single-neuron recording experiments, for example, the correlation of selectivity indices in a pair of tasks may be assessed across neurons, but, because the number of trials is limited, the measured index values for each neuron will be noisy. This attenuates the corre...

When a monkey executes a learned series of eye movements (for example, rightward followed by upward followed by leftward), neurons in the supplementary eye field (SEF) fire differentially in conjunction with the first, second, and third movements. It has not been clear whether such ordinal position signals are truly general, accompanying all forms...

We describe a novel application of atomic force microscopy (AFM) to directly visualize cytoskeletal fibers in human foreskin epithelial cells. The nonionic detergent Triton X-100 in a low concentration was used to remove the membrane, soluble proteins, and organelles from the cell. The remaining cytoskeleton can then be directly visualized in eithe...

The decrease in elasticity of epithelial tissues with ageing contributes to many human diseases. This change was previously attributed to increased crosslinking of extracellular matrix proteins. Here we show that individual human epithelial cells also become significantly more rigid during ageing in vitro. Using atomic force microscopy (AFM), we fo...

We used atomic force microscopy (AFM) to study the fundamentals of chemical mechanical polishing (CMP) of copper oxidized in an aqueous solution of 5 wt % peroxide and 1 wt % of glycine at varying pH levels. An AFM tip was used to mimic a single abrasive silica particle typical of those used in CMP slurry. AFM scanning removes the surface layer in...