Paul D R Gamlin - US grants

Whenever gaze is directed from a far target to a near target, vergence and accommodative eye movements ensure that a fused, well- focused image is achieved. Thus. vergence and accommodation are essential components of most eye movements. However, although disorders of ocular alignment and accommodation dysfunction are common clinical oculomotor complaints, little is known about the neurophysiological bases for vergence and accommodative eye movements. While a few studies have recorded motor or immediately premotor neurons in the midbrain and pretectum, the regions that provide inputs to these cells have not been identified. Identifying these regions, and the way in which vergence and accommodation signals are processed in them, should aid in our understanding of oculomotor complaints related to the near- response. Our preliminary studies in the alert primate have demonstrated that an additional region involved in the near-response is the cerebellum; specifically the posterior interpositus nucleus (PIN). The proposed project will therefore investigate the role of the PIN specifically, and the cerebellum in general in controlling vergence and accommodative eye movements. Single-units recording, lesion, microstimulation and anatomical techniques will be used in trained monkeys. Eye movements will be measured with the search coil technique, accommodation will be measured with an infrared optometer, and a visual stimulator will present targets with independent vergence and accommodative demands. Specifically, cells in the near-response region of the PIN will be tested to determine the aspects of vergence and accommodation that they are related to. Also, they will be tested to see if they are located before and after the links that cross-couple the vergence and accommodation systems. The functional significance of the near- response region of the PIN will be investigated using either reversible lidocaine or irreversible, ibotenic acid lesions. The regions of cerebellar cortex that project to the near-response region of the PIN will be identified using localized injections of WGA-HRP. Also, using microstimulation, the cerebellum will be surveyed to identify other regions related to vergence or accommodation. More detailed knowledge of this nature of the central neural processing of vergence and accommodative eye movements should aid in our understanding of strabismus, disorders of binocular vision, and accommodative dysfunction.

biomedical equipment purchase;

DESCRIPTION (Investigator's abstract): The long-term objective of these studies are to better understand the neural control of the pupil. When light is shone in one eye, pupilloconstriction occurs in both eyes and is termed the pupillary light reflex (PLR). With near viewing, convergence and accommodation are accompanied by a pupilloconstriction that is termed the pupillary near response. These pupillary responses are extremely useful to clinicians diagnosing the nature, severity, and extent of brain damage. Furthermore, detailed knowledge of the anatomy and physiology of the subcortical and cortical pathways involved in these pupillary responses is essential if the fledgling field of objective visual field testing using pupillometry (pupil perimetry) is to advance significantly. Unfortunately, there have been few recent studies of the neural control of these pupillary responses. Indeed, to my knowledge, our laboratory is currently only one of two in the world carrying out such up-to-date studies in alert, behaving primates. Therefore, despite the clinical importance of these pupillary responses, the literature is forced to rely on the results of experimental work that was mostly carried out before the advent of modern techniques. Hence, despite our recent extensive studies of the subcortical pupillary pathway in primates, there is still little or no data on the characteristics of the retinal ganglion cells that mediate the PLR, on the influences of the brainstem on the PLR, or on the role of the cerebral cortex in the PLR. To address these issues, we will use electrophysiological, anatomical, and pharmacological techniques in alert, behaving rhesus monkeys. We propose to determine the physiology, morphology, and immunohistochemical characteristics of the retinal ganglion cells that project to the pretectal olivary nucleus, the pretectal nucleus that mediates the PLR. We will characterize the brainstem afferents to this nucleus and the neurotransmitters within it. We will investigate the role of the cerebral cortex in influencing the PLR, we will study the effects of reversible and permanent lesions of striate cortex. In addition, permanent lesions of the dorsal prelunate gyrus will be used to study its involvement in the PLR. We will also use anatomical and electrophysiological techniques to investigate projections from the prelunate gyrus and other extrastriate visual areas to the pretectal olivary nucleus.

Vergence eye movements are required to foveate an object of interest located either behind or in front of the current fixation point. In addition, appropriate ocular accommodation is required to bring this object into focus. Problems with these eye movements may result in insufficient or excessive vergence and ocular accommodation. Furthermore, the inability to converge or diverge the eyes appropriately may result in strabismus, which can often lead to amblyopia in children. Unfortunately, very little is currently known about the areas of the brain involved in controlling these eye movements or about the sensorimotor transformations that are required for their neural control. Therefore, the long-term objectives of the proposed experiments are to obtain a better understanding of the neural circuits and sensorimotor transformations underlying these eye movements. Recently, a region of the prearcuate cortex immediately anterior to the frontal eye fields has been reported by us to contain neurons related to vergence and accommodation (near-response and far-response neurons) and neurons related to the visual cues that drive these eye movements such as disparity and blur. Identification of this cortical area is a significant step forward and, this application proposes to more closely examine its role in controlling vergence and accommodation. Specifically, experiments will examine the responses of neurons in this region of prearcuate cortex to the major visual cues for vergence and accommodation such as disparity and blur, as well as their responses to specific motion-in-depth cues. The visual responses of these neurons to static and motion-in-depth cyclopean targets will also be examined. The motor responses of these neurons will be studied during those vergence and accommodative eye movements required to look between stationary targets at different depths, and during those that are required to track targets moving in depth. To examine the characteristic of the vergence and accommodation signals sent to pontine regions by these prearcuate neurons, they will be antidromically activated from the nucleus reticularis tegmenti pontis, which possesses a well-defined vergence and accommodation region. To examine the functional role of this prearcuate area in vergence and accommodative eye movements, it will be ablated both unilaterally and bilaterally. Based on smooth pursuit and saccadic deficits following frontal eye field lesions, deficits are predicted in the ability to track targets moving in depth and in the ability to perform movements to remembered targets at different depths, and potential deficits in these abilities will be specifically investigated.

An open question in our understanding of language processing and speech production is whether a common phonological lexicon within the brain serves both speech production and word recognition. Data from studies of patients with lesions provide conflicting evidence about the neural substrates mediating phonological access, supporting both the common lexicon and dual lexicons hypotheses. fMRI studies using Echo-planar imaging (EPI) will be performed in 10 right-handed subjects. Our fMRI study uses tasks that systematically evaluate both input and output phonological processing, and should help resolve the uncertainty about the number of phonological lexicons and their structure and function. Four tasks will be applied in these studies: Auditory discrimination, Rhyme judgments, Lexical decisions, and Synonym judgments. The project is funded by an NIH R03 (1/01/98 to 12/31/98). Preliminary studies have been performed to verify the operation of the auditory stimulus hardware. The initial studies performed in this project will likely lead to more comprehensive studies in the future. This research may result in a better understanding of the brain pathways involved in phonological access for speech production and for word recognition, and may contribute to a better understanding of language development and disorders.[unreadable]

ABSTRACT

A grant has been awarded to Dr. Gamlin at the University of Alabama at Birmingham (UAB) to acquire a state-of-the-art vertical, 4.7 Tesla, magnetic resonance imaging (MRI) device designed especially for use with alert, trained non-human primates. MRI, especially functional MRI, is an exciting new tool that is revolutionizing our ability to study the brain. However, this technology has limitations when applied solely to humans. A major limitation is that once a brain region is identified by fMRI as being functionally activated during a specific task, additional invasive, experimental options are limited. However, by using non-human primates, further studies are not limited to imaging alone. One can conduct electrophysiological studies using single- and multi-unit recording, and neuroanatomical and pharmacological inactivation techniques to significantly enhance the level of understanding of brain function. Therefore, this 4.7T MRI system will be used in a primate Neuroimaging Facility which, when combined with existing neurophysiological techniques, will be able to examine brain function at both microscopic and macroscopic scales and with temporal resolutions of milliseconds - experiments that are not currently feasible in humans. In addition, using this combination of techniques, new pulse sequences will be developed and validated to ensure that fMRI images more accurately reflect the spatial and temporal characteristics of the underlying neural activity.
UAB has assembled a group of internationally-recognized neuroscientists with expertise in studying the underlying mechanisms of visual, sensorimotor, and oculomotor processing in alert, behaving primates. The primate visual system is the most extensively studied primate sensory system and the oculomotor system is the best understood primate motor system. Thus, these UAB investigators are in a unique position to fully exploit fMRI techniques to better understand the behavior of these model neural systems and, in so doing, contribute to a deeper understanding of brain function in general. The planned research projects will include the investigation of neural mechanisms related to vision, eye movements, plasticity, and sensorimotor integration in occipital, parietal, temporal, and frontal cortex. Other projects will involve the development of better functional and spectroscopic MRI techniques.
The planned Neuroimaging Facility, which will be one of only a few facilities in the world in which research spanning single neurons to whole brain behavior can be conducted in the same research animal, will be developed into a regional/national resource for research in Neuroscience. This planned facility thus has the potential to make major contributions to the field of functional brain research. The planned Neuroimaging Facility will have a major impact on recruitment and training of students in this emerging research area. Specifically, to ensure that the next generation of scientists will exploit this resource fully and develop MRI techniques further, participating faculty will ensure that students are trained in-depth in both neuroscience and MRI imaging. Further, UAB's Comprehensive Minority Faculty and Student Development Program, the NSF-funded Alliance for Minority Participation, and the Alliance for Graduate Education and the Professoriate Program, will ensure that a significant proportion of these students are from underrepresented groups.

DESCRIPTION (provided by applicant): Visual input to the suprachiasmatic nucleus (SCN) serves to entrain the circadian pacemaker while input to the pretectal olivary nucleus (PON) mediates the pupillary light reflex. In rodents, a population of intrinsically photoreceptive retinal ganglion cells projects to the PON and SCN, and are important to pupillary responses and entrainment of circadian rhythms. There is now compelling evidence that similar ganglion cells exist in primate retina, project to the ON and lateral geniculate nucleus, and contribute significantly to pupillary responses. The goals of the proposed studies in primates are therefore to: 1) further characterize these intrinsically-photoreceptive ganglion cells; 2) investigate their influence on the visual physiology of PON neurons; 3) examine their hypothesized projections to the SCN; 4) determine their influence on the visual physiology of SCN neurons; and 5) determine their contribution to pupillary responses in the primate. These are important research questions, since the circadian system regulates such physiologically important behaviors as activity, body temperature, and sleep/wake cycles, and the pupillary light reflex is a clinically important diagnostic tool. These studies have important implications for our understanding of the visual, circadian, and pupillary systems in primates. If, as preliminary data indicates, pupillary responses are influenced throughout much of the photopic range by inputs from intrinsically photoreceptive ganglion cells, this has important consequences for our understanding the pupillary light reflex and for its clinical evaluation. Also, if the same retinal ganglion cells project to both SCN and PON, then it will be possible to extrapolate from information that is readily derived in the pupillary system to the circadian system, where entrainment experiments take longer. Finally, beside their roles in pupil control and circadian rhythms, these ganglion cells project to the lateral geniculate nucleus and are likely to have very broad-reaching effect on other human visual behaviors.

Description (provided by applicant): This R21 exploratory proposal is designed to advance the integration of high field fMRI in alert macaque monkeys with "informed" neurophysiology, and to apply it in addressing a long-standing research question regarding the neural processing of stereoscopic 3-D motion. Stereo and motion are usually studied separately, and the cortical regions involved in the binocular perception of motion-in-depth in macaque monkeys are poorly characterized, while those for cyclopean (solely disparity-based) stereomotion perception are unknown. However, in humans, recent studies have identified specialized brain regions specifically involved in cyclopean stereomotion processing, including one near the motion complex hMT+, termed the cyclopean stereomotion region. We have developed techniques for performing fMRI studies at high-field in alert, behaving macaques. Therefore, employing the same visual stimuli as used in humans, we will use fMRI to identify cyclopean stereomotion regions in macaques, and to then characterize neuronal responses within one targeted region. The planned studies are relevant to health, since visual field deficits in stereomotion processing are closely correlated with deficits in vergence eye movements, and the same defect in binocular interaction appears to underlie both abnormal behaviors. Studies of the neural processing of stereomotion in non-human primates will not only provide insights into the cortical areas involved in processing this motion information and in controlling vergence eye movements, but will also potentially aid in the diagnosis and treatment of strabismus and diplopia. Specifically, using fMRI we will examine the cortical areas activated by cyclopean, motion-in-depth stimuli presented with dynamic random-dot stereograms (DRDS). These stimuli will be contrasted with appropriate, fixed-disparity DRDS stimuli. Our preliminary fMRI data from macaques have identified two well-localized foci of activation with these stimuli: one in the superior temporal sulcus (STS) in a location that partially coincides with MSTv, and the other is in the intraparietal sulcus. Next, since this is an exploratory grant of limited duration, we will concentrate our neurophysiological studies on the well-localized focus of activation within the STS. Specifically, using MRI-guided electrode placement in this targeted region, we will search for responsive neurons while the animals view cyclopean, motion-in-depth DRDS stimuli with the only cue to motion-in-depth being the change in disparity over time (CD). Next, using these stimuli, we will determine the receptive field size and location, and the speed tuning and z-axis directional selectivity of the neurons. Then, using RDS stimuli that possess both CD and interocular velocity difference motion-in-depth cues, we will examine neuronal response when both binocular cues to motion-in-depth are present. We will further characterize neuronal responses to stereomotion stimuli with frontoparallel and oblique trajectories, and during vergence eye movements. PUBLIC HEALTH RELEVANCE Accurate binocular alignment of the eyes on targets at different distances requires precisely coordinated movements of the two eyes, known as vergence eye movements;individuals with deficits in vergence eye movements are often strabismic and report diplopia (double-vision). Visual field deficits in stereomotion processing are closely correlated with deficits in vergence eye movements, and it has been suggested that the same defect in binocular interaction underlies both abnormal behaviors (Regan et al., 1986). Our studies of the neural processing of cyclopean stereomotion in non-human primates will not only provide fundamental insights into the cortical mechanisms involved in processing this motion information and in controlling vergence eye movements, but will also potentially aid in the diagnosis and treatment of strabismus and diplopia.

DESCRIPTION (provided by applicant): The oculomotor control system of foveate animals such as primates faces very diverse demands depending on the eye movement task. During some periods of time, the brain must precisely control the extraocular muscles so the eyes steadily fixate and stabilize the retinal image; during other periods, it must control the extraocular muscles to move the eyes rapidly from one position to another (saccades), or track objects of interest at widely differing speeds (smooth pursuit), or precisely change the viewing angle of the two eyes (vergence). It is currently assumed that these eye movements are produced through common pools of motor units (a motor unit is a motor neuron and its muscle fibers), recruited irrespective of task. But there is clear anatomic and histological evidence of motor unit diversity with physiological evidence of differential inputs from the oculomotor subsystems. Also, by directly measuring eye muscle forces using muscle force transducers (MFTs) and finding that they could not be predicted from neural innervation, we recently demonstrated that the simple concept of a final common motor path is incorrect (missing force paradox), and that this notion likely has impaired our understanding of the neuromuscular control of eye movements. In non-human primates, we propose to investigate how motor units with distinct characteristics and locations are recruited differentially for different horizontal ee motor tasks (saccades, smooth pursuit, and vergence) and task phases (phasic and tonic). We will identify lateral and medial rectus motoneurons using antidromic activation and spike-triggered averaging of electromyograms (STA-EMG), and measure motor unit functional properties using spike-triggered averaging of the muscle force transducer signal (STA-MFT), a new method we have recently validated. We will precisely localize motoneurons with X-ray images registered to MRI and histology, and fully characterize motor unit activity during these horizontal eye movements. Better understanding of eye motor control should lead to better treatment of eye movement disorders, such as strabismus. Drugs that modify eye muscle properties, elsewhere under development, show promise as simple, inexpensive office procedures able to effect corrections not possible with strabismus surgery. Our STA- MFT technique would be suitable to study the fiber type specific functionality of pharmacologically-modified motor units in alert animals. Relevance The novel techniques used in this proposal will allow us, for the first time, to study long-overlooked task specificities in the neuromuscular systems that stabilize and move our eyes for effective vision. These studies should result in more effective and less costly treatments for strabismus and other eye movement disorders that are of a neuromuscular origin.

? DESCRIPTION (provided by applicant): We sense light for a diverse array of functions that include regulation of the circadian clock, pupil diameter, hormone levels, and alertness. These non-image visual functions are distinguished from visual perception in that they are insensitive to details in the scene, being driven instead by the absolute level of illumination. Our goal is to understand the basis of these functions in a diurnal species whose visual system has strong homologies with that of humans. We focus on the intrinsically photosensitive retinal ganglion cells (ipRGCs), which respond directly to light using a receptor molecule called melanopsin, while also receiving inputs from rod- and cone-driven pathways. IpRGCs project their axons from the eye to numerous targets in the brain, with their two principal targets being the suprachiasmatic nucleus (SCN), which is the master circadian clock, and the pretectal olivary nucleus (PON), which is a control center for the pupillary light reflex. The clock and pupil exhibi marked, quantitative differences in their light responses. The clock integrates light over many minutes to produce an accurate measurement of overall irradiance, which provides a proxy for time of day; by contrast, the pupil senses light on a time scale of seconds to dynamically regulate the amount of light reaching the retina. Our broad hypothesis is that signaling mechanisms within the ipRGC system are suited to the integrative character of non-image vision in a diurnal mammal, and tuned to specific downstream functions. To test this hypothesis, we will determine the phototransduction mechanisms and spatiotemporal dynamics of ipRGCs that innervate the SCN or PON; furthermore, we will connect these features to the spatiotemporal dynamics of SCN and PON neurons. Our experiments rely on a synergy of in vitro and in vivo neurophysiological techniques. We have established a logistical and technological platform that allows the ipRGC system to be defined in stepwise fashion across multiple levels of biological organization, from photon absorption by melanopsin to the chromatic sensitivities of downstream neurons and behavioral outputs. Our experiments will constitute the first extensive and systematic investigation of the ipRGC system in a diurnal mammal, and will lay the foundation for a precise understanding of links that have been made between dysregulation within this system and human diseases that include cancer, cardiovascular disease, metabolic disorders, psychiatric disorders, and jet lag. The strong commonalities between our model organism and humans make the translational relevance of our research especially direct.

Instrumentation Core 7. Project Summary/Abstract The Instrumentation Core is a new configuration of two long-standing service modules: the Machine Shop Module and the Electronics Module. Services previously provided by each module are all still available and represent some of the main goals and strengths of this Core. In addition, by bringing these two previously independent modules together under a single directorship, we have instituted greater coordination between services to facilitate the complex fabrication that is increasingly among the goals of Instrumentation Core users. For example, this reconfiguration allows for the coordinated design of devices with integrated electro- mechanical components, which streamlines production by considering structural and electronic features simultaneously in the initial design phase. Such added goals ensure that the Instrumentation Core is a focal point where investigators can work with the Core staff as a team to design and improve electro-mechanical devices that are central to data acquisition for new as well as ongoing experiments. Both the machine shop and the electronics components of this Core are staffed by highly skilled technicians. Because the machinist is experienced with on-going scientific projects by Core users, he routinely offers design and materials recommendations that help to improve and expedite project outcomes. This design process is further facilitated by the tool and ide maker?s recently acquired Associate degree in computer-aided drafting and design. The electrical engineer, newly hired during the past year, is completing a Bachelor?s degree in Electrical Engineering at UAB, and consequently will be providing fresh insight into the latest technologies for device control and signal acquisition. Like his predecessor in this engineering position, his efforts will be additionally motivated by occasional co-authorship in publications, as warranted. The improved coordination of the Core staff under a one Director/one Associate Director team is expected to increase effective communication between Core staff and scientists, leading to increased productivity. At present, the re-configured Core is used extensively or moderately by 14 of the 23 Core grant participants, of which 8 are NEI R01-funded.

Funds are requested for three shared instruments to greatly improve pre-, intra-, and post- operative ocular imaging in experimental animals to: 1) allow detailed preoperative planning and assessment of baseline values; 2) improve outcomes of intraocular procedures minimizing surgical complications; 3) assure a complete assessment of eye health for postoperative care; 4) greatly enhance quantitative assessment of physiological/pathological processes and research/treatment outcomes. Specifically, we request: 1) Zeiss Lumera 700 ReScan system with Resight 700 operating microscope with intraoperative optical coherence tomography (OCT) imaging (1400 hrs annually); 2) FLEX Module Spectralis OCT2 System for imaging the retina and optic nerve head in animals at various body positions (1600 hrs annually); 3) Anterior Segment CASIA SS-1000 swept source OCT for imaging the cornea, iris, and lens in large animals, as well as the whole eye in small animals (1600 hrs annually). The research of 12 NIH-funded UAB faculty members critically needs the requested equipment to enhance and push forward their collective research programs. This requested equipment forms a synergistic cluster for the proposed user group, who are investigating glaucoma, myopia, gene therapy, stem cells, retinal biology, and central visual projections. The use of these instruments will speed development of strategies to understand basic disease mechanisms and develop new therapies to improve human health. Specifically, intraoperatively, the Zeiss Lumera 700 ReScan system will allow us to perform OCT-guided ocular surgical procedures with greater accuracy, and with the ability to precisely document the locations of injections, instruments and implants. Pre- and postoperatively, the FLEX Module Spectralis Tracking OCT System and the Anterior Segment CASIA SS-1000 swept source OCT will allow us to quantitatively assess the characteristics and health of the retina, RPE, choroid, and optic nerve head, as well as anterior chamber structures (lens, cornea, iris, trabecular meshwork) in vivo. Together, these instruments will allow us to quantitatively assess the health, experimental treatment, damage, recovery, and/or inflammation of ocular tissues and structures preceding, during, and following a wide array of ocular procedures that are central to the success of the NIH-funded user group. Thus, this equipment will undoubtedly strengthen the research programs of the participating faculty and accelerate translation of experimental therapeutics into humans. The instruments will be housed in a university-wide core facility for ocular phenotyping. The PI has a demonstrated track record of over 20 years of administration, and of successfully managing core and departmental services.

ABSTRACT Mutations in GUCY2D, the gene encoding retinal guanylate cyclase-1 (retGC1), are the leading cause of autosomal dominant cone-rod dystrophy. GUCY2D-CORD6 patients present with loss of visual acuity, abnormal color vision, photophobia, visual field loss and macular atrophy within the first decade. Rod degeneration and peripheral visual field loss follow. Significant progress towards clinical application of gene replacement therapy for LCA due to recessive mutations in GUCY2D (LCA1) has been made, but a different approach is needed to treat CORD6 where gain of function mutations cause dysfunction and dystrophy. Our preliminary data show that 1) selective and efficient somatic knock-out of GUCY2D and Gucy2e (murine homologue) with AAV- CRISPR/Cas9 results in a subsequent loss of retinal structure/function that manifests from reduced retGC1 expression in macaque and mouse, respectively, 2) a ?knock-out + complementation in trans? approach (wherein complementation is performed with ?hardened? Gucy2e not recognized by Gucy2e gRNA) preserves retinal function in mice, 3) AAV-CRISPR/Cas9- based editing of GUCY2D is therapeutic in a R838S transgenic (Tg) mouse model of CORD6, and 4) Cas9 variants identified by directed evolution exhibit allele specificity for GUCY2D(R838S). We will build upon these results in the following Aims. Aim 1 will establish the optimal parameters for AAV-CRISPR/Cas9-based gene editing in two R838S CORD6 Tg mouse lines. We will establish the optimal AAV capsid/dose, durability of therapy, treatment window, and feasibility of transient Cas9 expression systems. Aim 2 will evaluate safety/efficacy of AAV-CRISPR/Cas9-based gene editing in macaque by looking for off-target editing and assessing the potential impact of AAV vector insertions and long-term Cas9 expression. We will also evaluate regional differences in editing efficiency and conduct dose-ranging studies. Aim 3 will compare ?knock out + complementation in trans? vs. ?allele-targeted? approaches for treating CORD6. The optimal AAV capsids and Cas9 expression system from Aim 1 will be used to test KO + complementation in GC2-/- mice. Allele-targeted editing will be performed in humanized R838S CORD6 mice that carry both the wt and R838S- containing exon 13 of GUCY2D. Approaches will include a novel, engineered Cas9 that specifically edits the R838S mutant allele, gRNAs containing mismatches to mutant but not wt allele, or utilization of an alternative PAM site found in the mutant, but not wt allele. Successful approaches will be tested in macaque for efficiency/safety. Our findings will identify the optimal capsid/dose, and treatment age for therapeutic AAV- CRISPR/Cas9-based disruption of R838S GUCY2D in vivo. We will establish the safety profile, and regional efficiencies of gene editing by AAV-CRISPR/Cas9 in a species with both genomic and clinical relevance. In addition, we will identify materials and approaches that will allow clinical application of AAV-CRISPR/Cas9 therapies for CORD6 as well as other dominantly inherited retinal diseases.

UAB Center Core for Vision Science - Machine Shop Core Project Summary/Abstract The Machine Shop remains an essential Core servicing the researchers in Vision Science at UAB. It enables custom components to be designed and built to accommodate uncommon species (e.g. tree shrew, macaque) for which commercial equipment is unavailable or unsuitable for the novel science being pursued. The Core also enables new instruments to be built or commercially incompatible components to be melded for new purposes. Whenever it is practical to do so, all new device and component designs are now initiated with digital drawings in AutoCAD, which seamlessly operates with two new major pieces of equipment: a computer- numerically-controlled (CNC) milling machine and a 3-D printer for high-end materials. Our move to a digital platform streamlines the manufacturing process by minimizing trial-and-error in new devices and improves precision and repeatability. The digital approach also helps to educate trainees on the feasibility and practicality of their designs, as they can learn to visualize the final product without having to make it first. Our machinist is now experienced with on-going scientific projects by Core users, the wide range of new materials available (biocompatible alloys and plastics), and he routinely offers design and materials recommendations that improve and expedite project outcomes. The design process is further facilitated by the machinist?s recently acquired Associate degree in computer-aided drafting. Currently the Machine Shop Core is used extensively or moderately by 14 of the 25 Core Grant participants.