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Project Title:  VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing (80NSSC22K0022) Reduce
Images: icon  Fiscal Year: FY 2024 
Division: Human Research 
Research Discipline/Element:
HRP HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Start Date: 12/14/2021  
End Date: 12/13/2024  
Task Last Updated: 10/14/2023 
Download report in PDF pdf
Principal Investigator/Affiliation:   Davis, Catherine M. Ph.D. / Henry M. Jackson Foundation 
Address:  6720-A Rockledge Dr. 
 
Bethesda , MD 20817-1891 
Email: catherine.davis-takacs@usuhs.edu 
Phone: 301-295-5826  
Congressional District:
Web:  
Organization Type: NON-PROFIT 
Organization Name: Henry M. Jackson Foundation 
Joint Agency:  
Comments: Campus address (Jan 2022): Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814. NOTE: PI formerly at Johns Hopkins University; moved to Henry M. Jackson Foundation for the Advancement of Military Medicine in fall 2020.  
Co-Investigator(s)
Affiliation: 
Hienz, Robert  Ph.D. Johns Hopkins University 
Robinson, Siobhan  Ph.D. Hamilton College 
Project Information: Grant/Contract No. 80NSSC22K0022 
Responsible Center: NASA JSC 
Grant Monitor: Whitmire, Alexandra  
Center Contact:  
alexandra.m.whitmire@nasa.gov 
Unique ID: 14822 
Solicitation / Funding Source: 2016-2017 HERO NNJ16ZSA001N-SRHHC. Appendix E: Space Radiobiology and Human Health Countermeasures Topics 
Grant/Contract No.: 80NSSC22K0022 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Human Research Program Risks: None
Human Research Program Gaps: None
Flight Assignment/Project Notes: End date corrected to 12/13/2024 per V. Lehman/JSC Grants Office (Ed., 2/28/2024).

End date changed to 12/13/2025 per NSSC information (Ed., 10/26/23).

Task Description: [Ed. note Jan 2022: Continuation with same Principal Investigator (PI) Dr. Catherine Davis, of "VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing," grant #80NSSC18K1080 when PI was at Johns Hopkins University. See also project, "VNSCOR: Responses of the Nervous System to Chronic, Low Dose Charged Particle Irradiation" (Principal Investigator (PI): Greg Nelson)]

NELSON/DAVIS VIRTUAL NASA Specialized Center of Research (NSCOR): The project is organized as 5 large experimental campaigns to quantify responses for an interrelated set of central nervous system (CNS) outcome measures in mice to acute and protracted exposures to protons at a dose of 0.5 Gy and sham controls; acute and protracted exposures to 0.25 and 0.5 Gy of charged particles; and acute and protracted exposures to 0.5 and 1.5 Gy of gamma rays. This research builds on previous studies that demonstrated that proton and HZE (high charge energy) exposures result in individual differences in deficits in sustained attention, but more general deficits in recognition memory. This current project is combined with "Responses to the Nervous System to Chronic, Low Dosed Charged Particle Irradiation" (PI: Nelson) in order to explore if these effects are LET (linear energy transfer)-dependent for 16O ions, add a relatively understudied, but important, ion (4He), and examine CNS effects in whole animals following fractionated exposures, and the interaction of other space flight factors (e.g., sleep fragmentation).

Revised Specific Aims:

Aim 1a: Effects of protracted exposure to five-ion GCR [galactic cosmic rays] sim (1H, 4He, 28Si, 16O, 56Fe)

Aim 1b: Effects of protracted exposure to protons only

Aim 1c: Acute exposure to 4He (250 MeV/n)

Aim 2a: Neuronal activation and molecular markers following radiation

Aim 2b: Chemogenetic silencing of mPFC subregions

Specific Aims:

1) Determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance. (This aim has been modified in order to integrate with Nelson project);

2) Determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures;

3) Determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure (This aim has been modified in order to integrate with Nelson project);

4) Examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

ORIGINAL PROPOSAL DESCRIPTION: Assessing the biological consequences of living in the space radiation environment represents one of the highest priority areas of NASA research. Of critical importance is the need for an assessment of the vulnerabilities of the central nervous system (CNS) leading to functional neurobehavioral changes during long-term space missions, and the development of effective countermeasures to such risks. The present proposal addresses this need via the application of an animal model to 1) determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance; 2) determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures; 3) determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure; and 4) examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

Prior research has 1) identified rats that are sensitive to radiation-induced deficits in sustained attention and 2) shown that acute, single ion exposures alter social motivation and social odor recognition memory. The current proposal will determine how the immediate effects of irradiation impact subsequent neurobehavioral deficits by assessing various behavioral, physiological, and neurobiological markers of radiation exposure at early and later time points post-exposure. Groups of animals will be trained on a rodent version of the human psychomotor vigilance test, exposed to radiation, and then tested for both social processing and sustained attention deficits following exposure; subsets of rats will be implanted with biotelemetry devices to measure fluctuations in spontaneous locomotor activity and body temperatures following radiation exposure and changes in sleep or circadian disruptions. Individual variations in these behavioral, physiological, or neurobiological responses following radiation will be assessed. Likely mechanisms of damage to the CNS following radiation exposure will be examined using brain tissue, in addition to a pharmacogenetic technique to determine the severity of radiation-induced neurobehavioral deficits.

Research Impact/Earth Benefits: The results of the current project will be used to understand how radiation exposure affects the central nervous system to induce deficits in neurobehavioral function.

Task Progress & Bibliography Information FY2024 
Task Progress: During the reporting period, we exposed male and female rats to acute protons (0.5 Gy, 0.25 Gy at 250 MeV/n, and 0.25 Gy at 1000 MeV/n). These exposures will be used to understand how protons, the most abundant ions in galactic cosmic rays (GCR), affect various cognitive domains and will be compared to exposures to the simplified GCR simulation at the same total dose (0.5 Gy).

82 rats (53 male and 29 female) were shipped to Brookhaven National Laboratory and irradiated with acute protons. Some of the rats were previously trained on the rPVT. Following exposure, all rats were tested for social odor recognition memory (SORM) at 7 days, 30 days, 90 days, and 6 months following radiation exposure. A subset of animals completed rPVT testing following radiation, from approximately 30 days to 6 months following exposure. Finally, both males and females were tested in the open field test, and a subset of male and female rats were tested for social interaction. Following each time point, a subset of animals was sacrificed to collect brain, blood, heart, eye, and bone samples. In preliminary analyses of the data, radiation exposure significantly impaired social odor recognition memory, but limited sex differences were found. Social interaction was altered in proton-exposed male rats, but this exposure did not alter these behaviors in female rats. For the rPVT, results suggest that acute proton exposure has limited effects on overall group performance, but analysis of individual animals is ongoing. These data appear to replicate our previously published data showing limited effects of proton exposure on sustained attention; importantly, deficits.

We are currently preparing for a chronic proton exposure in NASA Space Radiation Laboratory (NSRL) run 23C, where we will expose groups of male and female rats to 50 cGy protons for comparison to our GCR sim studies.

Bibliography: Description: (Last Updated: 10/27/2023) 

Show Cumulative Bibliography
 
Articles in Peer-reviewed Journals Alwood JS, Mulavara AP, Iyer J, Mhatre S, Rosi S, Shelhamer S, Davis CM, Dinges D, Mao XW, Desai RI, Elgart SR, Whitmire A, Williams TJ. "Circuits and biomarkers of the central nervous system relating to astronaut performance: Summary report for a NASA-sponsored technical interchange meeting." Life (Basel) 2023; 13(9): 1852. https://doi.org/10.3390/life13091852 ; PMID: 37763256; PMCID: PMC10532466 , Aug-2023
Articles in Peer-reviewed Journals Russ E, Davis CM, Slaven JE, Bradfield DT, Selwyn RG, Day RM. "Comparison of the medical uses and cellular effects of high and low linear energy transfer radiation." Toxics. 2022 Oct 21;10(10): 628. https://doi.org/10.3390/toxics10100628 ; PMID: 36287908; PMCID: PMC9609561 , Oct-2022
Significant Media Coverage Neligh I. (Davis C interview) "How does cosmic radiation affect the brain? One USU professor aims to find out. " Dr. Davis interviewed for USU News, an internal Uniformed Services University (USU) publication. https://news.usuhs.edu/2023/01/how-does-cosmic-radiation-affect-brain.html#:~:text=She%20says%20even%20low%20levels ,%2C%E2%80%9D%20Davis%2DTakacs%20says , Jan-2023
Project Title:  VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing (80NSSC22K0022) Reduce
Images: icon  Fiscal Year: FY 2023 
Division: Human Research 
Research Discipline/Element:
HRP HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Start Date: 12/14/2021  
End Date: 12/13/2023  
Task Last Updated: 10/15/2022 
Download report in PDF pdf
Principal Investigator/Affiliation:   Davis, Catherine M. Ph.D. / Henry M. Jackson Foundation 
Address:  6720-A Rockledge Dr. 
 
Bethesda , MD 20817-1891 
Email: catherine.davis-takacs@usuhs.edu 
Phone: 301-295-5826  
Congressional District:
Web:  
Organization Type: NON-PROFIT 
Organization Name: Henry M. Jackson Foundation 
Joint Agency:  
Comments: Campus address (Jan 2022): Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814. NOTE: PI formerly at Johns Hopkins University; moved to Henry M. Jackson Foundation for the Advancement of Military Medicine in fall 2020.  
Co-Investigator(s)
Affiliation: 
Hienz, Robert  Ph.D. Johns Hopkins University 
Robinson, Siobhan  Ph.D. Hamilton College 
Project Information: Grant/Contract No. 80NSSC22K0022 
Responsible Center: NASA JSC 
Grant Monitor: Whitmire, Alexandra  
Center Contact:  
alexandra.m.whitmire@nasa.gov 
Unique ID: 14822 
Solicitation / Funding Source: 2016-2017 HERO NNJ16ZSA001N-SRHHC. Appendix E: Space Radiobiology and Human Health Countermeasures Topics 
Grant/Contract No.: 80NSSC22K0022 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Human Research Program Risks: None
Human Research Program Gaps: None
Task Description: [Ed. note Jan 2022: Continuation with same Principal Investigator (PI) Dr. Catherine Davis, of "VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing," grant #80NSSC18K1080 when PI was at Johns Hopkins University. See also project, "VNSCOR: Responses of the Nervous System to Chronic, Low Dose Charged Particle Irradiation" (Principal Investigator (PI): Greg Nelson)]

NELSON/DAVIS VIRTUAL NASA Specialized Center of Research (NSCOR): The project is organized as 5 large experimental campaigns to quantify responses for an interrelated set of central nervous system (CNS) outcome measures in mice to acute and protracted exposures to protons at a dose of 0.5 Gy and sham controls; acute and protracted exposures to 0.25 and 0.5 Gy of charged particles; and acute and protracted exposures to 0.5 and 1.5 Gy of gamma rays. This research builds on previous studies that demonstrated that proton and HZE (high charge energy) exposures result in individual differences in deficits in sustained attention, but more general deficits in recognition memory. This current project is combined with "Responses to the Nervous System to Chronic, Low Dosed Charged Particle Irradiation" (PI: Nelson) in order to explore if these effects are LET (linear energy transfer)-dependent for 16O ions, add a relatively understudied, but important, ion (4He), and examine CNS effects in whole animals following fractionated exposures, and the interaction of other space flight factors (e.g., sleep fragmentation).

Revised Specific Aims:

Aim 1a: Effects of protracted exposure to five-ion GCR [galactic cosmic rays] sim (1H, 4He, 28Si, 16O, 56Fe)

Aim 1b: Effects of protracted exposure to GCR sim without protons (4He, 28Si, 16O, 56Fe)

Aim 1c: Effects of protracted exposure to protons only

Aim 1d: Acute exposure to 4He (250 MeV/n)

Aim 2a: Neuronal activation and molecular markers following radiation

Aim 2b: Chemogenetic silencing of mPFC subregions

Specific Aims:

1) Determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance. (This aim has been modified in order to integrate with Nelson project);

2) Determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures;

3) Determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure (This aim has been modified in order to integrate with Nelson project);

4) Examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

ORIGINAL PROPOSAL DESCRIPTION: Assessing the biological consequences of living in the space radiation environment represents one of the highest priority areas of NASA research. Of critical importance is the need for an assessment of the vulnerabilities of the central nervous system (CNS) leading to functional neurobehavioral changes during long-term space missions, and the development of effective countermeasures to such risks. The present proposal addresses this need via the application of an animal model to 1) determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance; 2) determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures; 3) determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure; and 4) examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

Prior research has 1) identified rats that are sensitive to radiation-induced deficits in sustained attention and 2) shown that acute, single ion exposures alter social motivation and social odor recognition memory. The current proposal will determine how the immediate effects of irradiation impact subsequent neurobehavioral deficits by assessing various behavioral, physiological, and neurobiological markers of radiation exposure at early and later time points post-exposure. Groups of animals will be trained on a rodent version of the human psychomotor vigilance test, exposed to radiation, and then tested for both social processing and sustained attention deficits following exposure; subsets of rats will be implanted with biotelemetry devices to measure fluctuations in spontaneous locomotor activity and body temperatures following radiation exposure and changes in sleep or circadian disruptions. Individual variations in these behavioral, physiological, or neurobiological responses following radiation will be assessed. Likely mechanisms of damage to the CNS following radiation exposure will be examined using brain tissue, in addition to a pharmacogenetic technique to determine the severity of radiation-induced neurobehavioral deficits.

Research Impact/Earth Benefits: The results of the current project will be used to understand how radiation exposure affects the central nervous system to induce deficits in neurobehavioral function.

Task Progress & Bibliography Information FY2023 
Task Progress: During the reporting period, we exposed male and female rats to the simplified galactic cosmic radiation (GCR) simulation, either a single acute dose (50 cGy) or chronic dosing (2.08 cGy per day/6 days per week for 4 total weeks; 50 cGy total dose). This was a replicate of the same dose rate study we ran in 2019. This replicate was previously canceled due to the COVID-19 pandemic.

60 rats (30 male and 30 female) were shipped to Brookhaven National Laboratory and irradiated with the GCR simulation. Some of the rats were previously trained on the rPVT. [Ed. Note: The rPVT is a sustained attention test that requires subjects to monitor the location of a stimulus that occurs infrequently.] Following exposure, all rats were tested for social odor recognition memory (SORM) at 7 days, 30 days, 90 days, and 6 months following radiation exposure. A subset of animals completed rPVT testing following radiation, from approximately 30 days to 6 months following exposure. Following the 6-month time point, all animals were sacrificed to collect brain and blood samples. In preliminary analyses of the data, radiation exposure significantly impaired social odor recognition memory; but limited sex differences were found for the early time points. For the rPVT, results suggest that both acute and chronic GCR sim exposure can impair performance, and these effects could be more robust in female animals.

We also completed statistical analysis of the rPVT data from 4He exposed male rats. Using a fully saturated ANCOVA-type linear mixed effects model, we found significant dose-dependent changes in rPVT performance parameters. More specifically, exposure to 25 cGy significantly decreased accuracy (percent correct responding), increased false alarms (impulsive responding), and increased in several different reaction time measures. Interestingly, exposure to 5 cGy only induced changes in a few reaction time measures, but had no significant effect on other measures, including accuracy, false alarms, and lapses in attention.

Blood samples from both 4He-exposed and GCR sim-exposed rats are being analyzed for the presence of specific miRNAs that have previously been shown to be associated with exposure to various spaceflight factors, including radiation and microgravity. Our study seeks to determine if any of these miRNAs can be used as biomarkers of these behavioral deficits.

We are currently preparing for an acute proton exposure in NASA Space Radiation Laboratory (NSRL) run 22C, where we will expose groups of male and female rats to 50 cGy protons for comparison to our GCR sim studies.

Bibliography: Description: (Last Updated: 10/27/2023) 

Show Cumulative Bibliography
 
Articles in Peer-reviewed Journals Thomas PK, Sullivan LK, Dickinson GH, Davis CM, Lau AG. "The effect of helium ion radiation on the material properties of bone." Calcif Tis Int. 2021 Jan 30;108:808-18. https://doi.org/10.1007 s00223-021-00806-7 ; PMID: 33517470 , Jan-2021
Articles in Peer-reviewed Journals Davis CM, Allen AR, Bowles DE. "Consequences of space radiation on the brain and cardiovascular system." J Environ Sci Health C Toxicol Carcinog. 2021 Apr 27;39(2):180-218. https://doi.org/10.1080/26896583.2021.1891825 ; PMID: 33902387 , Apr-2021
Articles in Peer-reviewed Journals Boerma M, Davis CM, Jackson IL, Schaue D, Williams JP. "All for one, though not one for all: team players in normal tissue radiobiology." Int J Radiat Biol. 2021 Jul 198(3):346-66. https://doi.org/10.1080/09553002.2021.1941383 ; PMID: 34129427. , Jul-2021
Articles in Peer-reviewed Journals Jones CB, Peiffer LB, Davis CM, Sfanos KS. "Examining the effects of 4He exposure on the gut-brain axis." Radiat Res. 2021 Mar 1;197(3):242-52. https://doi.org/10.1667/RADE-20-00285.1 ; PMID: 34752622 , Mar-2022
Awards Davis C. "American Society for Pharmacology and Experimental Therapeutics JH Woods Early Career Award in Behavioral Pharmacology" Apr-2022
Project Title:  VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing (80NSSC22K0022) Reduce
Images: icon  Fiscal Year: FY 2022 
Division: Human Research 
Research Discipline/Element:
HRP HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Start Date: 12/14/2021  
End Date: 12/13/2023  
Task Last Updated: 01/26/2022 
Download report in PDF pdf
Principal Investigator/Affiliation:   Davis, Catherine M. Ph.D. / Henry M. Jackson Foundation 
Address:  6720-A Rockledge Dr. 
 
Bethesda , MD 20817-1891 
Email: catherine.davis-takacs@usuhs.edu 
Phone: 301-295-5826  
Congressional District:
Web:  
Organization Type: NON-PROFIT 
Organization Name: Henry M. Jackson Foundation 
Joint Agency:  
Comments: Campus address (Jan 2022): Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814. NOTE: PI formerly at Johns Hopkins University; moved to Henry M. Jackson Foundation for the Advancement of Military Medicine in fall 2020.  
Co-Investigator(s)
Affiliation: 
Hienz, Robert  Ph.D. Johns Hopkins University 
Robinson, Siobhan  Ph.D. Hamilton College 
Project Information: Grant/Contract No. 80NSSC22K0022 
Responsible Center: NASA JSC 
Grant Monitor: Whitmire, Alexandra  
Center Contact:  
alexandra.m.whitmire@nasa.gov 
Unique ID: 14822 
Solicitation / Funding Source: 2016-2017 HERO NNJ16ZSA001N-SRHHC. Appendix E: Space Radiobiology and Human Health Countermeasures Topics 
Grant/Contract No.: 80NSSC22K0022 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:  
No. of PhD Candidates:  
No. of Master's Candidates:  
No. of Bachelor's Candidates:  
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) HFBP:Human Factors & Behavioral Performance (IRP Rev H)
Human Research Program Risks: None
Human Research Program Gaps: None
Task Description: [Ed. note Jan 2022: Continuation with same Principal Investigator (PI) Dr. Catherine Davis, of "VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing," grant #80NSSC18K1080 when PI was at Johns Hopkins University. See also project, "VNSCOR: Responses of the Nervous System to Chronic, Low Dose Charged Particle Irradiation" (Principal Investigator (PI): Greg Nelson)]

NELSON/DAVIS VIRTUAL NASA Specialized Center of Research (NSCOR): The project is organized as 5 large experimental campaigns to quantify responses for an interrelated set of central nervous system (CNS) outcome measures in mice to acute and protracted exposures to protons at a dose of 0.5 Gy and sham controls; acute and protracted exposures to 0.25 and 0.5 Gy of charged particles; and acute and protracted exposures to 0.5 and 1.5 Gy of gamma rays. This research builds on previous studies that demonstrated that proton and HZE (high charge energy) exposures result in individual differences in deficits in sustained attention, but more general deficits in recognition memory. This current project is combined with "Responses to the Nervous System to Chronic, Low Dosed Charged Particle Irradiation" (PI: Nelson) in order to explore if these effects are LET (linear energy transfer)-dependent for 16O ions, add a relatively understudied, but important, ion (4He), and examine CNS effects in whole animals following fractionated exposures, and the interaction of other space flight factors (e.g., sleep fragmentation).

Revised Specific Aims:

Aim 1a: Effects of protracted exposure to five-ion GCR [galactic cosmic rays] sim (1H, 4He, 28Si, 16O, 56Fe)

Aim 1b: Effects of protracted exposure to GCR sim without protons (4He, 28Si, 16O, 56Fe)

Aim 1c: Effects of protracted exposure to protons only

Aim 1d: Acute exposure to 4He (250 MeV/n)

Aim 2a: Neuronal activation and molecular markers following radiation

Aim 2b: Chemogenetic silencing of mPFC subregions

Specific Aims:

1) Determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance. (This aim has been modified in order to integrate with Nelson project);

2) Determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures;

3) Determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure (This aim has been modified in order to integrate with Nelson project);

4) Examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

ORIGINAL PROPOSAL DESCRIPTION: Assessing the biological consequences of living in the space radiation environment represents one of the highest priority areas of NASA research. Of critical importance is the need for an assessment of the vulnerabilities of the central nervous system (CNS) leading to functional neurobehavioral changes during long-term space missions, and the development of effective countermeasures to such risks. The present proposal addresses this need via the application of an animal model to 1) determine the effects of acute, single 16O and 4He ion exposures on sustained attention, social odor recognition memory, and social dominance; 2) determine the effects of a fractionated exposure on sustained attention and recognition memory in comparison to the effects of single ion exposures on these measures; 3) determine the effects of circadian disruptions and sleep fragmentation on sustained attention and recognition memory following radiation exposure; and 4) examine the underlying mechanisms of these deficits using immunohistochemical and pharmacogenetic procedures.

Prior research has 1) identified rats that are sensitive to radiation-induced deficits in sustained attention and 2) shown that acute, single ion exposures alter social motivation and social odor recognition memory. The current proposal will determine how the immediate effects of irradiation impact subsequent neurobehavioral deficits by assessing various behavioral, physiological, and neurobiological markers of radiation exposure at early and later time points post-exposure. Groups of animals will be trained on a rodent version of the human psychomotor vigilance test, exposed to radiation, and then tested for both social processing and sustained attention deficits following exposure; subsets of rats will be implanted with biotelemetry devices to measure fluctuations in spontaneous locomotor activity and body temperatures following radiation exposure and changes in sleep or circadian disruptions. Individual variations in these behavioral, physiological, or neurobiological responses following radiation will be assessed. Likely mechanisms of damage to the CNS following radiation exposure will be examined using brain tissue, in addition to a pharmacogenetic technique to determine the severity of radiation-induced neurobehavioral deficits.

Research Impact/Earth Benefits: The results of the current project will be used to understand how radiation exposure affects the central nervous system to induce deficits in neurobehavioral function.

Task Progress & Bibliography Information FY2022 
Task Progress: New project for FY2022.

Note this is continuation, with same Principal Investigator (PI) Dr. Catherine Davis, of "VNSCOR: Mechanisms of Radiation-Induced Changes in Sustained Attention and Social Processing," grant 80NSSC18K1080 when PI was at Johns Hopkins University. See that project for previous reporting.

Bibliography: Description: (Last Updated: 10/27/2023) 

Show Cumulative Bibliography
 
 None in FY 2022