NIMH Instrumentation Core Facility

National Institute Of Mental Health

Investigators

Linked publications, trials & patents

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 292 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. These arrays are also used for precise injection of chemicals to specific regions of the brain. With the Section's newly acquired Polyjet printer we are able to print mechanically rigid bases with the correct curvature to allow direct placement of multiple hold grid arrays. 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. 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. The 3D design and printing capabilities have increased with the recent addition of both professional 3D printers and our Staff. SI is able to print fMRI head coils holders with complex curved surfaces with more efficiency and accuracy. There are various primate chair designs that allow fMRI scanning of primates. SI continues to provide considerable effort in the design and fabrication of primate chair systems to incorporate new features as requested by researchers. 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. The fabrication of marmoset behavioral monitoring systems has increased dramatically. SI designs and fabricates a variety of transport boxes and testing systems. These systems attach directly to the animals home cage. This approach, rather than bringing the animals into the lab, facilitates collecting data from a larger number of animals more efficiently. This arrangement also reduces stress and facilitates social learning, as other marmosets in the room can observe ongoing experiments through transparent plexiglass walls of the box. Touchscreens can show a large variety of static and dynamic images. This approach will be used to examine changes in behavior across adolescent development, and to study cognitive and social behavior in marmosets. Human and Clinical: SI continues the development of a novel ECT system. 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 non-focal 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. The ECT system is a multi-year collaboration, incorporating the development of a considerable amount of custom electronics and custom software development. SI has completed the design of the individual channel boards and the main motherboard. Considerable effort remains on software development and testing the system with high voltages and currents. This past FY, SI used some of the software concepts and hardware from the Cinnamon ECT system to quickly design and fabricate a single channel version with an enhanced user interface for testing ECT on NHPs. 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. SI is redesigning and fabricated several behavioral testing systems that will be used to provide a platform for studies using a technique known as total internal reflection fluorescence microscopy. Key events in cellular trafficking occur at the cell surface, and it is desirable to visualize these events without interference from other regions deeper within. The technique has many other applications as well, most notably for studying biochemical kinetics and single biomolecule dynamics at surfaces. 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.