NIMH Instrumentation Core Facility

National Institute Of Mental Health

Investigators

Linked publications & trials

Abstract

This past year, our Section had the unique opportunity to support the research of various Labs & Sections within NIMH, NINDS, NICHD, and NCCIH. During the past twelve months, investigators from these labs and branches requested 441 formal projects from our staff. Each of these requests was documented and the time recorded to complete the job. In addition to the formal requests we are available daily for numerous walk-in, phone call or e-mail requests for assistance. In general, our technical support this past year can be divided into the following research areas: Electrophysiology The Section on Instrumentation staff continuously strives to improve the utility of various components that comprise electrophysiology. We have continued to improve the engineering and fabrication of multiple-hole grid arrays that allow precise, repeatable placement of a single or multiple electrodes over a wide area. We have also continued to develop small single-electrode microdrives. Novel methods using 3D printing now allow for the production of low-component count yet accurate and smooth microdrives. The Section on Instrumentation designed a multichannel amplifier array and extension to enable low-noise recording of insect brains. The headstage extension splits the input to a 16-channel extracellular amplifier into four independently maneuverable headstages. This is useful for simultaneously recording neuronal activity from different regions of the insect brain, as well as recording from a larger set of neurons in a given brain region using multiple tetrodes in parallel. fMRI/MRI The Section on Instrumentation provides a wide range of support for fMRI-related research. Fabrication of devices for use in MRI environments is a specialized area of expertise, with great attention given to design without ferrous metals and minimization of all metal components. In addition, commercial industrial fiber optic components and systems are evaluated and integrated into many designs and devices we fabricate. The Section on Instrumentation supports the installation of new equipment in MRI suites, including custom mirror and projection assemblies used for stimulus presentation, and custom RF-shielded penetration panels used to route cabling. SI is designing and fabricating a system that will allow accurate and precise location of a primate chair in the new 3T magnet for the Section on Cognitive Neurophysiology and Imaging (SCNI). This will be used to undertake studies on the large-scale organization of visuoperceptual processing in the brain. Non-Human Primate (NHP) Our group is responsible for providing a wide range of engineering and fabrication services to support non-human primate research. Many of the mechanical assemblies that are necessary for this type of research are engineered and fabricated in-house. Our group provides a diverse array of custom systems and components to many different investigators, such as custom primate chairs, high-strength restraints, MRI positioning systems, custom head coils, reward systems, data acquisition, analysis and optical response systems, plus a wide range of small mechanical components. SI is assisting in the construction of a 3D virtual reality dome. The dome projects images and movies reflected from a spherical mirror on to the dome's surface. In order to achieve audio functionality, SI plans to add an array of speakers to the dome surface and cover these speakers with an acoustically transparent screen to maintain the geometric illusion of the dome. Shaping the acoustically transparent screen to match the shape of the dome will require a 3D-printed skeleton assembled on the dome to hold the screen taut while covering the foam and speakers on the dome surface. The skeleton needs to be prototyped, designed, printed, and assembled from multiple pieces each holding a section of the sheet to approximate a dome shape. This skeleton is a crucial element to adding audio and enabling a proper exploration of audiovisual integration in the brain. Human In collaboration with the Experimental Therapeutics & Pathophysiology Branch, the Section on Instrumentation is developing a multi-channel ECT system (iLAST). While modifications of ECT have improved its safety and tolerability, none of the currently used procedures individualize the current amplitude for each patient despite knowledge that anatomical variation significantly impacts the strength of the current delivered to the brain. iLAST introduces three areas of improvement over conventional ECT. 1) Conventional ECT uses two large disc electrodes that are spaced widely apart, which leads to a nonfocal electric field distribution in the brain. In iLAST, we use a multi-electrode array to selectively target regions of the brain similar to one employed in high-definition tDCS studies. 2) Conventional ECT uses a high and fixed current amplitude (800 mA). The fixed current amplitude is much higher than necessary to elicit an adequate seizure, and also results in individual differences in the amount of current entering the brain, possibly leading to variability in clinical outcome. In iLAST, we titrate the amplitude of the current for each patient. 3) Conventional ECT monitors seizure induction with two-channel EEG recording in the prefrontal cortex, which does not characterize seizure topography. In iLAST, we will use high-density EEG electrodes that are weaved into the multi-stimulation electrode array so that topographical ictal EEG is recorded. Behavioral Several different types of mazes are used to study spatial learning and memory in rats. These studies have been used to help understand general principles about learning that can be applied to humans, and to determine how different treatments affect learning and memory in mice. We continue to produce a variety of custom T and Y mazes for behavioral testing. Imaging The Section on Instrumentation continues to produce a variety of equipment that supports two-photon microscopy, such as novel titanium headposts and stereotaxic frames, faraday cages for electronic and light shielding and custom mirror mounts. In addition, behavioral testing equipment such as low-inertia mouse wheels are fabricated for use with two-photon microscopy. Clinical Our Section also supports a number of clinical based research requests under the broad areas of surgical, therapeutic and basic research. The Section on Instrumentation continued its development on an automated compressometer that delivers accurate and repeatable pressure to different areas of the leg for studies that explore basic mechanisms of affective touch perception, including how people perceive the intensity, painfulness, and/or pleasantness of deep pressure involving peripheral sensory nerve and central brain mechanisms. This includes perceptual thresholds and ratings as well as brain imaging. In addition, the system will be used for studying how perception of affective touch, including deep pressure, alters processing of acute and chronic pain, in individuals with and without chronic pain conditions. The system is operated automatically by a computer running LabVIEW software with the requisite input/output electronics. Technology By using the latest technology in advanced fabrication machinery, we are able to increase productivity and effectiveness while at the same time decreasing the amount of time needed to engineer and machine the components. Our waterjet cutter continues to increase our cutting and fabricating capabilities, especially with the multiple fiberglass parts we produce. With this system, we are able to fabricate a variety of miniature titanium headposts that would have been very difficult to machine with conventional tooling. Our Carbon Fiber 3D Printer allows us to print high strength complex organic shaped parts.