NIMH Instrumentation Core Facility

National Institute Of Mental Health

Investigators

Linked publications & trials

Abstract

This past year, the Section on Instrumentation (SI) 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 236 formal projects from our staff. Each of these requests was documented and the time to complete the job was recorded. 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 strive 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. 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. SI 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 has devoted considerable resources to provide a solution for allowing accurate and precise monkey chair insertion and fixation in the 3T magnet for the Section on Cognitive Neurophysiology. 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 systems, analysis and optical response systems, as well as a wide range of small mechanical components. SI has responded to a continued increase in marmoset-based research by providing a variety of custom designed and fabricated marmoset testing systems, a wide variety of habitats, marmoset transport boxes, and marmoset reward systems. Human and Clinical SI continues the development of a novel Electroconvulsive therapy (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 which is currently one of the most effective treatments available for treatment resistant depression but has residual side effects. 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. 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. 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 devoted a considerable amount of its effort this fiscal year in supporting the research of the Spatial Navigation and Memory Unit (NINDS); this research is primarily interested in the medial entorhinal cortex (MEC), which plays a key role in spatial representation and episodic memory. The MEC is a part of the medial temporal lobe and serves as the main gateway between the hippocampal formation and the neocortex. Dysfunction of the MEC is closely associated with Alzheimer's Disease (AD), the most common form of dementia. AD patients generally exhibit severe loss of episodic memory and have difficulty in spatial navigation. SI fabricated a testing system that allows a head-fixated mouse to navigate through a virtual reality system. This system was initially developed by Princeton University, but it did not meet the requirements requested by the lead investigator. The mouse is held directly over a nearly frictionless styrofoam ball inside of a spherical dome on which video images are projected. Optical sensors detect the movement of the ball and translate this to a moving image on the dome. Auditory stimulation is provided by an array of speakers around the mouse, with a custom sound card and amplifier system that enables a sound to be output and moved seamlessly from any direction. 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 components. We recently acquired a high-precision 3D printer that allows us to print plastics with different durometers. Our waterjet cutter continues to increase our cutting and fabricating capabilities, especially with the multiple fiberglass parts we produce. The waterjet allows us to quickly fabricate systems that require many assembled pieces of flat stainless or polycarbonate, and to fabricate titanium headposts that are very difficult to machine with conventional tooling. Our Carbon Fiber 3D Printer allows us to print high strength complex organic shaped parts.