1977 — 1978 |
Lasek, Raymond |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
A Putative Contractive Atpase Associated With Neurofiliments @ Case Western Reserve University |
0.915 |
1983 |
Lasek, Raymond |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Conference On Cell Biology of Neuronal Plasticity, June 6-10, 1983, Capo Caccia, Sardinia, Italy @ Case Western Reserve University |
0.915 |
1985 — 1993 |
Lasek, Raymond J |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Aging Changes in Neuronal Function and Structure @ Case Western Reserve University
During postnatal development and continuing through the aging process, there are changes in the dynamic metabolic processes that maintain the structural and functional properties of axons. For exampIe, the rate of slow transport decreases during maturation and aging. Our studies are aimed at elucidating the cell biological mechanisms that produce these changes in aging axons. To achieve this goal, we are examining the factors that affect the translocation of cytoskeletal polymers in axons. Our premise is that the slow transport mechanisms operate by producing polymer sliding movements. To directly examine polymer sliding in axons we have developed a new experimental method for slowly stretching axoplasm at rates approaching those of slow transport. With this method the resistance of polymers to sliding can be measured directly. In addition, we are using the electron microscope to study the interactions between axonal neurofilaments in axons with different slow transport rates. If these interactions are imporant determinants of transport rate, then the organization of the neurofilaments should correlate with the rate of transport. Cytoskeletal and membranous elements are transported to the axon terminal and they provide the materials for axon terminal structures. The amount of material available at the terminal is determined by the rate of supply to the terminal and removal from the terminal. In aging terminals, the balance between supply and removal changes and in some neurons excess membranous and cytoskeletal elements accumulate at the terminals. This excess may be produced by a decrease in the rate of removal from the axon terminal. To examine this possibility, we are using radioisotopic methods, to determine whether the rate of removal changes during aging. These studies will contribute to understanding the mechanisms that normally operate to remove excess materials from axon terminals and to understanding how changes in these mechanisms contribute to changes in the properties of axon terminals during aging.
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1 |
1985 — 1991 |
Lasek, Raymond J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Axonal Regeneration in Spinal Cord @ Case Western Reserve University
Research on the regeneration of axons in the long fiber tracts of mammalian spinal cord would benefit from the development of an effective experimental model. We plan to analyze the regenerative capacity of rat dorsal root ganglion cells in order to provide the fundamental base of information required to develop such an experimental model. The dorsal root ganglion cell was chosen because it innervates both the central nervous system and periphery. Furthermore, these cells send axons in both myelinated and unmyelinated fiber tracts of the spinal cord, the dorsal columns and tract of Lissauer respectively. The regenerative capacity of both central and peripheral branches of adult rat L-4 dorsal root ganglion cells will be analyzed. We will use radioactive precursors to label the ganglion cell axons by axonal transport and measure the latency and rate of axonal regeneration in the dorsal root and sciatic nerve. After characterizing the properties of regeneration of the axons in the dorsal root, we will evaluate the capacity of these axons to continue regenerating from the dorsal root into the spinal cord. For this analysis anterograde autoradiographic tracing will be used, and the newly regenerated axons will be mapped with the light and electron microscope. Whether or not the axons regenerate into the spinal cord, we will have a valuable model for studying regeneration. For example, if the axons stop growing when they reach the spinal cord, we will be able to analyze the factors which stop the axons from regenerating. However, if the axons regenerate into the spinal cord, we will be able to study the regeneration of axons in adult mammalian spinal cord and determine whether the dorsal root axons regenerate into the long ascending fiber tracts when the spinal cord is not damaged directly. This project can contribute to our understanding of central nervous system regeneration at two levels: 1) by developing an experimental model so that axonal regeneration can be studied in the mammalian spinal cord and 2) by employing this model to compare the mechanisms involved in the regeneration of axons in the central and peripheral nervous system.
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1 |
1985 — 1987 |
Lasek, Raymond J |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Developmental Neurology Training Grant @ Case Western Reserve University |
1 |
1985 — 1989 |
Lasek, Raymond J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Intrinsic Mechanisms of Axonal Growth and Regeneration @ Case Western Reserve University
I propose to continue my studies of the mechanisms within the axon that are involved in the formation of newly regenerating daughter axons. We will focus specifically on those processes of axonal growth that are relatively independent of changes in transcription and translation in the neuron cell body. The cytoskeleton of a newly regenerated axon is apparently derived from the cytoskeleton of its parent axon. These cytoskeletal elements, which are provided exclusively by slow axonal transport, accumulate at the cut end of the axon. We have proposed that the cytoskeleton is reorganized in this region of the axon and that it is then transported into the regenerating daughter axon. In order to study this process, we have developed a new method for studying the transport of the cytoskeleton from the parent axon into the daughter regenerate. In this method, the cytoskeletal proteins of rat motor axons are selectively labeled by slow axonal transport. This method will be employed to compare the composition and dynamics of the cytoskeleton in parent axons and daughter axons. The goal of these studies is to elucidate the local mechanisms that are involved in the transformation of the axonal cytoskeleton during regeneration. Another aspect of these studies on the basic mechanisms of axonal elongation concerns the translocation of the cytoskeleton through the axon. The squid giant axon will be the primary model used to test the hypothesis that actin and myosin are involved in the mechanisms of cytoskeletal translocation within the axon.
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1 |
1986 — 1987 |
Lasek, Raymond |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Meeting On Intrinsic Determinants of Neuronal Form and Function - May 12-15, 1986; Cleveland, Ohio @ Case Western Reserve University |
0.915 |