1985 — 2013 |
Steinbach, Joseph H. |
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. |
Acetylcholine Receptor Function |
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1992 — 1996 |
Steinbach, Joseph H. |
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. |
Anesthetics &Analgesics--Cellular &Molecular Actions
The mechanisms by which general anesthetics and analgesics have their clinically desired effects are not understood. The work proposed in this Program seeks to define the molecular target(s) for these drugs, and to clarify the way in which action at these targets results in anesthesia or analgesia. The underlying idea is that these drugs act on proteins, and in particular on membrane channels involved in information transfer between neurons at synapses. The available data indicate that anesthetics and analgesics can affect a number of membrane channels (both voltage- and ligand-gated), and that some of the changes could underlie a decrease in excitability of nerve cells. Unfortunately, there are few quantitative data which allow determination of the specificity of effects, or assessment of the likelihood that a given effect might be related to production of the clinically desired results. One goal of the Program is to determine likely neuronal targets of anesthetics and analgesics, by quantitatively examining the dose-effect relationship of drug action on membrane currents in neurons. One project will study effects on voltage-gated calcium- selective channels (Drs. Lingle ), which are of central importance in activity-dependent transmitter release and neuronal excitability. Two projects will study drug actions on postsynaptic transmitter-gated channels (Drs. Covey and Steinbach), which are essential to the response of the postsynaptic cell. Comparing and contrasting the results of these studies will indicate channels whose function is altered by clinically relevant concentrations of drug, and will determine which actions are characteristic of anesthetics or analgesics. A final goal of the Program is to elucidate the mechanism by which anesthetics and analgesics have their effects on proteins, by analyses of pharmacological and kinetic data obtained in the projects. The results obtained will provide information required to determine likely cellular and molecular actions which underlie the clinically desired effects of these drugs. Furthermore, insights will be gained into the mechanisms by which anesthetics and analgesics have their actions.
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1996 — 2011 |
Steinbach, Joseph H. |
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. |
Anesthetic Action On Neurotransmitter Responses
PROJECT 3 This Project will study the actions of steroid anesthetics on transmitter-gated ion channels. The focus is on potentiation of responses of the GABA-A receptor by steroids, as potentiation is most clearly related to anesthetic actions. A central goal of the work is to define the structural requirements for specific steroid effects. Work in the present funding period has shown that steroids have 3 distinct kinetic effects on the GABA-A receptor, and that the effects are mediated by binding to at least 2 sites. We will use biophysical analyses of evoked currents to determine the structures of the steroid molecule which are required for these effects, in complementary experiments, we will study the consequences of mutations to proposed steroid binding regions in the GABA-A receptor. We will also perform experiments to identify the location of the steroid binding pocket in the receptor with respect to the cell membrane, that is, whether it is located in the inner or outer leaflet of the membrane. In studies performed during the present funding period, we have found that the effects of steroids depend on the concentration of transmitter (GABA) used to activate the receptor, which may have a significant role in shaping the physiological actions of steroids. We will study the basis for the this relationship. We will continue to produce recombinant epitope tagged GABA-A receptors, for use in biochemical studies. Finally, we will determine the effects of steroids on the function of additional receptors, including the glycine a3 receptor. The proposed work builds on previous results from this Project and the Program as a whole. It is expected to lead to significant insights into the nature and location of the steroid binding sites on the GABA- A receptor. Further, it is expected to reveal the critical molecular mechanisms by which steroid anesthetics produce functional effects associated with anesthesia. Finally, it should assist in developing insights into the parts of the steroid molecule which are associated with specific functional consequences, which could result in increased specificity or efficacy for steroid anesthetics.
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1997 — 2001 |
Steinbach, Joseph H. |
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. |
Anesthetics--Cellular and Molecular Actions
The mechanisms by which general anesthetics have their clinically desired effects are not understood. The work proposed in the Program seeks to define the molecular target(s) for these drugs, and to clarify the way in which action at these targets results in anesthesia. The underlying idea is that anesthetics act at defined sites on proteins and , in particular, the proteins involved in formation transfer between neurons. A major emphasis of the Program is to understand the properties of steroid anesthetics, as a result of progress in the preceding Program is to understand the properties of steroid anesthetics, as a result of progress in the preceding Program period. One objective of the Program is to define the actions of steroid anesthetics on several classes of membrane channel, including GABA- A receptors, glutamatergic receptors, neuronal nicotinic receptors and voltage-gate calcium channels. The second objective of the Program is to define the structural basis for steroid interaction with on specific target, the GABA-A receptor. These studies will involve complementary studies of steroid analogue structure and molecular manipulation of recombinant receptor subunits. Photo-activated site specific probes for steroid binding sites will also be developed. The third objective of the Program is to delineate the mechanisms by which steroid anesthetics have their effects on their targets. The final objective is to correlate pharmacological results with production of anesthesia or other states defined only at the whole animal level. Although the overall focus is on anesthetic steroids, the program will include examination of additional anesthetics for comparison to the steroids. Each project, then, addresses on or another aspect of the action of anesthetic drugs at the cellular and molecular level. The Program as a whole will integrate these complementary studies, and relate them to behavioral states.
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2002 — 2006 |
Steinbach, Joseph H. |
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. |
Anesthetics: Cellular &Molecular Actions
GRANT=6521568;P01GM The mechanisms by which general anesthetics have their clinically desired effects are not yet fully understood. The work proposed in this Program is designed to define the molecular target(s) for anesthetic steroids and to clarify the way in which action at these targets results in anesthesia. The underlying idea is that steroid anesthetics act at defined sites on proteins and, in particular, the proteins involved in formation transfer between neurons. The proposed research will build on a series of advances made in proceeding periods of the Program, which have provided insights into the sites and mechanisms of action for steroids. One objective of the Program is to define the actions of steroids on several classes of membrane channel, including GABA-A receptors, glutamatergic receptors and glycinergic receptors. The second objective of the Program is to define the structural basis for steroid interaction with one specific target, the GABA-A receptor. This work will involve complementary studies to modify the structure of the receptor and to examine the structures labeled by site-specific photo-activated steroid analogues. The third objective of the Program is to clarify the mechanisms by which steroids have their actions on their molecular targets. The final objective of the Program is to clarify the mechanisms by which steroids have their actions on their molecular targets. The final objective is to correlate the pharmacological and physiological results with the production of anesthesia or other states defined only at the level of the whole animal. Although the focus is anesthetic steroids, the Program will include examination of additional anesthetics for comparison to the steroids. Each project addresses one or other aspect of the action of anesthetic steroids at the cellular and molecular level. The Program as a whole will integrate these complementary studies and provide the resources for continued development of novel compounds and for assays of dry effects on behavioral states.
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2004 — 2008 |
Steinbach, Joseph H. |
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. |
Aceytylcholine Receptor Function
DESCRIPTION (provided by applicant): Nicotine is a highly addictive substance, and nicotine dependence results in major public health costs. Nicotine acts on specific receptors in the brain, neuronal nicotinic receptors, whose physiological properties and role in the brain are not well understood. The proposed work will examine the pharmacology and physiology of a major class of human brain receptors, composed of alpha 4 and beta 2 subunits. The overall goal is to define fundamental properties of these receptors, including basic properties of activation and desensitization, and the actions of specific drugs. To provide a defined population of receptors, the work will use receptors expressed in non-neural cells, either transiently or stably. The aims of the work are, first, to define the mechanisms by which some drugs potentiate the function of these receptors. The second aim is to define the mechanisms by which selected drugs block the function of these receptors. The third aim is to characterize desensitization of these receptors, including very low concentrations of nicotine. The final aim is to define the signal, which elicits an increase in the expression of these receptors. The first two aims will provide essential information about the actions of several drugs, including some in clinical use. The third aim will increase our understanding of the regulation of receptor activity by long-term exposure to nicotine and other drugs, including concentrations, which are reached in the brain of smokers. The final aim will use the insights gained in the previous work to gain an understanding of the mechanism by which ceils can increase the numbers of these receptors which they express on their surface. In addition to the actions of nicotine itself, drugs which act on nicotinic receptors are being used or proposed for use in treating a number of disorders, including Alzheimer's disease, attention deficit disorder and pain. Our understanding of the actions of these drugs is hampered our lack of knowledge about the mechanisms of their effects on the target nicotinic receptors. Furthermore, it is known that decreases in the expression of the alpha 4 beta 2 receptor are associated with some disorders, so increased understanding of the nature of the signal for upregulation may provide insights into these disorders and, possibly, therapeutic approaches. Overall, the proposed work will examine basic properties of receptors, to reach a greater understanding of receptor function and pharmacology, which can be applied to understanding the role of these receptors in normal and pathological brain function.
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2005 |
Steinbach, Joseph H. |
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. |
Anesthetics Cellular and Molecular Actions
[unreadable] DESCRIPTION (provided by applicant): Certain endogenous steroids and their synthetic analogues (neuroactive steroids) produce profound and rapid effects on the central nervous system ranging from general anesthesia to seizures. While these effects are thought to result from steroid interactions with specific binding sites on the GABA-A receptor, molecular biological studies have failed to identify candidate regions or residues that might contribute to a binding site. The overall goal of this project is to identify and characterize the binding sites with which neuroactive steroids interact to produce their inhibitory (anesthetic) effects. Two novel neurosteroid analogue photoaffinity labeling reagents, CW12 (a Sa-reduced steroid) and CW14 (a 5p-reduced steroid) have been developed to achieve this goal. Both CW12 and CW14 are potent and efficacious modulators of GABA-A receptor function. When these reagents are exposed to UV light at 350 nM, they form a reactive group (a carbene) that allows them to covalently attach to (photolabel) their binding site. Assays of GABA-A receptor function in brain membranes provide strong evidence that CW12 and CW14 efficiently and selectively photolabel the neuroactive steroid binding site(s) responsible for modulation of GABA-A receptor function. This project has two specific aims. The first is to identify and characterize the GABA-A receptor-associated proteins that are photolabeled by CW12 and/or CW14 in rat brain. The second aim is to determine the GABA-A receptor subunit specificity of neuroactive steroid binding and action by photolabeling HEK cells transfected with various combinations of epitope-tagged GABA-A receptors and correlating the functional effects of photolabeling with the specific subunits that are photolabeled. In both aims, photolabeled proteins will be isolated using immunoprecipitation and two-dimensional electrophoresis and then identified and sequenced using tandem mass spectrometry. The information gained from this project will provide the background knowledge and tools to: (1) determine how endogenous neurosteroids modulate CNS function in health and disease and; (2) develop new pharmaceutical agents including potent steroidal anesthetics with minimal side effects, novel anticonvulsants and anxiolytics and neuroactive steroid antagonists. [unreadable] [unreadable]
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2007 |
Steinbach, Joseph H. |
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. |
Administrative Core |
1 |
2007 — 2011 |
Steinbach, Joseph H. |
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. |
Anesthetics: Cellular and Molecular Actions
[unreadable] DESCRIPTION (provided by applicant): The mechanisms by which general anesthetics have their clinically desired effects are not yet fully understood. The work proposed in this Program is designed to define the molecular target(s) for anesthetic steroids and to clarify the way in which action at these targets results in anesthesia. The underlying idea is that steroid anesthetics act at defined sites on proteins and, in particular, the proteins involved in information transfer between neurons. The proposed research will build on a series of advances made in preceding periods of the Program, which have provided insights into the sites and mechanisms of action for steroids. One objective of the Program is to define the structural basis for steroid interaction with a specific target, the GABA-A receptor. This work will involve complementary studies of the structure-activity relationship for steroid analogues and mutational studies of receptor structure coupled with identification of the residues labeled by site-specific photo-activated steroid analogues. The second objective of the Program is to clarify the mechanisms by which steroids have their actions on their molecular targets, including studies of functional effects on target proteins and examination of steroid access. The third objective is to examine the role of steroid partitioning among cellular membrane pools in determining the time course and magnitude of steroid action. The final objective is to correlate the pharmacological and physiological results with the production of anesthesia or other states defined only at the level of the whole animal. Although a major focus is on studies of the GABA-A receptor, comparative studies of glutamatergic, glycinergic and GABA-C receptors will be performed. Each project addresses one or another aspect of the action of anesthetic steroids at the cellular and molecular level. The Program as a whole will integrate these complementary studies and provide the resources for continued development of novel compounds and for assays of drug effects on behavioral states. [unreadable] [unreadable] [unreadable]
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