Loss of Cognitive Flexibility Practice Effects in Female Rats Exposed to Simulated Space Radiation.

During the planned missions to Mars, astronauts will be faced with many potential health hazards including prolonged exposure to space radiation. Ground-based studies have shown that exposure to space radiation impairs the performance of male rats in cognitive flexibility tasks which involve processes that are essential to rapidly and efficiently adapting to different situations. However, there is presently a paucity of information on the effects of space radiation on cognitive flexibility in female rodents.

Impairments and compensation in string-pulling after middle cerebral artery occlusion in the rat.

Stroke is a leading cause of long-term disability in humans, and it is frequently associated with impairments in the skilled use of the arms and hands. Many human upper limb impairments and compensatory changes have been successfully modeled in rodent studies of neocortical stroke, especially those that evaluate single limb use in tasks, such as reaching for food. Humans also use their hands for bilaterally coordinated movements, dependent upon interhemispheric cortical projections, which are also compromised by unilateral stroke.

Multiple decrements in switch task performance in female rats exposed to space radiation.

Astronauts on the Artemis missions to the Moon and Mars will be exposed to unavoidable Galactic Cosmic Radiation (GCR). Studies using male rats suggest that GCR exposure impairs several processes required for cognitive flexibility performance, including attention and task switching. Currently no comparable studies have been conducted with female rats.

Spatial Disorientation Under Dark Conditions Across Development in an Alzheimer's Disease Mouse Model.

Alzheimer's disease (AD) is associated with hippocampal neuropathology and cognitive impairments, including wandering behavior or becoming lost in a familiar environment. Wandering behavior is severe and manifests early in life for people with specific genetic mutations. Genetic mouse models of AD have been developed to characterize the onset and progression of behavioral deficits that represent human behaviors, such as wandering, to test the efficacy of therapeutics.

Fine motor deficits exhibited in rat string-pulling behavior following exposure to sleep fragmentation and deep space radiation.

Deep space flight missions will expose astronauts to multiple stressors, including sleep fragmentation and space radiation. There is debate over whether sleep disruptions are an issue in deep space. While these stressors independently impair sensorimotor function, the combined effects on performance are currently unknown.

Similar Loss of Executive Function Performance after Exposure to Low (10 cGy) Doses of Single (4He) Ions and the Multi-Ion GCRSim Beam.

While astronauts are trained to deal with multiple issues that they are likely to encounter during a mission, it is likely that some problems will arise that astronauts have no direct experience in resolving. During International Space Station (ISS) missions, astronauts can rely on Mission Control to help resolve complex problems, however during the long-duration space missions planned to the Moon and Mars, astronauts will have to act more autonomously, thus the ability of astronauts to conduct executive function will be critical for problem solving during deep space missions. Several studies have shown that exposure to space radiation results in decreased executive function performance.

Similar Loss of Executive Function Performance after Exposure to Low (10 cGy) Doses of Single (4He) Ions and the Multi-Ion GCRSim Beam.

While astronauts are trained to deal with multiple issues that they are likely to encounter during a mission, it is likely that some problems will arise that astronauts have no direct experience in resolving. During International Space Station (ISS) missions, astronauts can rely on Mission Control to help resolve complex problems, however during the long-duration space missions planned to the Moon and Mars, astronauts will have to act more autonomously, thus the ability of astronauts to conduct executive function will be critical for problem solving during deep space missions. Several studies have shown that exposure to space radiation results in decreased executive function performance.

Rapid loss of fine motor skills after low dose space radiation exposure.

Sensorimotor function, motivation, and attentional processes are fundamental aspects of behavioral organization during skilled tasks. NASA's planned expedition to Mars will expose astronauts to space radiation (SR) that has the potential to impair performance in mission critical tasks. Impairments in task accuracy and movement kinematics have been previously reported during string-pulling behavior ~7 months after SR exposure.

Exposure to 5 cGy 28Si Particles Induces Long-Term Microglial Activation in the Striatum and Subventricular Zone and Concomitant Neurogenic Suppression.

The proposed mission to Mars will expose astronauts to space radiation that is known to adversely affect cognition and tasks that rely on fine sensorimotor function. Space radiation has also been shown to affect the microglial and neurogenic responses in the central nervous system (CNS). We recently reported that a low dose of 5 cGy 600 MeV/n 28Si results in impaired cognition and skilled motor behavior in adult rats.

Organization of exploratory behavior under dark conditions in female and male rats.

Sexually dimorphic performance has been observed across humans and rodents in many spatial tasks. In general, these spatial tasks do not dissociate the use of environmental and self-movement cues. Previous work has demonstrated a role for self-movement cue processing in organizing open field behavior; however, these studies have not directly compared female and male movement characteristics.

Effects of acquired vestibular pathology on the organization of mouse exploratory behavior.

Rodent open field behavior is highly organized and occurs spontaneously in novel environments. This organization is disrupted in mice with vestibular pathology, suggesting vestibular signals provide important contributions to this behavior. A caveat to this interpretation is that previous studies have investigated open field behavior in adult mice with congenital vestibular dysfunction, and the observed deficits may have resulted from developmental changes instead of the lack of vestibular signals.

Skilled movement and posture deficits in rat string-pulling behavior following low dose space radiation (Si) exposure.

Deep space flight missions beyond the Van Allen belt have the potential to expose astronauts to space radiation which may damage the central nervous system and impair function. The proposed mission to Mars will be the longest mission-to-date and identifying mission critical tasks that are sensitive to space radiation is important for developing and evaluating the efficacy of counter measures. Fine motor control has been assessed in humans, rats, and many other species using string-pulling behavior.

Effects of string length on the organization of rat string-pulling behavior.

The string-pulling paradigm has been adapted to investigate many psychological phenomena across a range of animal species. Although varying string length has been shown to influence performance, the nature of the representation remains to be determined. Across three experiments, rats were shaped to pull string to receive food reinforcement.

Human string-pulling with and without a string: movement, sensory control, and memory.

String-pulling is a behavior that is allied to many daily acts and is an easily performed action featuring hand-over-hand movements to reel in a string (or rope). String-pulling has been used as a test of perceptual and cognitive functions in many animal species, including human children, but its movements and sensory control have not been characterized. Male and female university students (n = 68) performed target-based or memory-based string-pulling in which they pulled down a string suspended on an overhead pulley and immediately afterwards attempted to make the same movement in a memory-based test.

The structure of arm and hand movements in a spontaneous and food rewarded on-line string-pulling task by the mouse.

Arm and hand use by the mouse have been studied in a variety of tasks in order to understand the structure of skilled movements and motor learning, the anatomy and function of neural pathways, and to develop animal models of neurological conditions. The present study describes string-pulling by the mouse, a behavior in which a mouse uses hand-over-hand movements to pull down a string that hangs from the top of a test cage. Mice both spontaneously string-pull and also string-pull to obtain cashew nuts tied to the end of the string as food reward.

Unilateral forelimb sensorimotor cortex devascularization disrupts the topographic and kinematic characteristics of hand movements while string-pulling for food in the rat.

String-pulling by the rat is a bimanual act, in which an upright animal retrieves a piece of food attached to the end of the string by downward hand-over-hand movements. The present study compared the movements of string-pulling, using topographic and kinematic measures of hand movement, in control rats and rats with unilateral sensorimotor motor cortex lesion produced by removal of the pia matter. In the first week following devascularization, the rhythmicity and accuracy of string-pulling movements decomposed; however, thereafter the rhythm of bilateral alternation was restored.

A history of adolescent binge drinking in humans is associated with impaired self-movement cue processing on manipulatory scale navigation tasks.

A binge drinking pattern of alcohol consumption has been shown to have an impact on brain structures that continue to develop into late adolescence. These same brain structures have been implicated in processing self-movement cues. The current study applies an array of existing and novel kinematic analysis techniques to characterize performance on manipulatory scale tasks to assess spatial orientation deficits associated with a history of adolescent binge drinking.

Cholinergic deafferentation of the hippocampus causes non-temporally graded retrograde amnesia in an odor discrimination task.

Dementia of the Alzheimer's type (DAT) is a neurodegenerative disorder marked by loss of hippocampal cholinergic tone and significant memory impairments, specifically for memories acquired prior to disease onset. The nature of this relationship, however, remains debated. The current study used the string pulling task to evaluate the temporal effects of odor discrimination learning in animals with selective cholinergic lesions to determine the role of the septohippocampal cholinergic system in mnemonic function.

Otolithic information is required for homing in the mouse.

Navigation and the underlying brain signals are influenced by various allothetic and idiothetic cues, depending on environmental conditions and task demands. Visual landmarks typically control navigation in familiar environments but, in the absence of landmarks, self-movement cues are able to guide navigation relatively accurately. These self-movement cues include signals from the vestibular system, and may originate in the semicircular canals or otolith organs.