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- Creators: Department of Psychology
- Creators: Honeycutt, Claire
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
Women are now living longer than ever before, yet the age of spontaneous menopause has remained stable. This results in an increasing realization of the need for an effective treatment of cognitive and physiological menopausal and post-menopausal symptoms. The most common estrogen component of hormone therapy, conjugated equine estrogens (CEE; Premarin) contains many estrogens that are not endogenous to the human body, and that may or may not be detrimental to cognition (Campbell and Whitehead, 1977; Engler-Chiurazzi et al., 2011; Acosta et al., 2010). We propose the use of a novel treatment option in the form of a naturally-circulating (bioidentical) estrogen called estriol. Due to estriol’s observed positive effects on synaptic functioning and neuroprotective effects in the hippocampus (Ziehn et al., 2012; Goodman et al., 1996), a brain structure important for spatial learning and memory, estriol is promising as a hormone therapy option that may attenuate menopausal- and age- related memory decline. In the current study, we administered one of the three bioidentical estrogens (17β-Estradiol, 4.0 µg/day; Estrone, 8.0 µg/day; Estriol, 8.0 µg/day) or the vehicle polyethylene glycol by subcutaneous osmotic pump to ovariectomized Fisher-344 rats. We compared these groups to each other using a battery of spatial learning tasks, including the water radial-arm maze (WRAM), Morris water maze (MM), and delayed-match-to-sample maze (DMS). We found that all estrogens impaired performance on the WRAM compared to vehicle, while 17β-estradiol administration improved overnight forgetting performance for the MM. The estriol group showed no cognitive enhancements relative to vehicle; however, there were several factors indicating that both our estriol and estradiol doses were too high, so future studies should investigate whether lower doses of estriol may be beneficial to cognition.
ContributorsStonebarger, Gail Ashley (Author) / Bimonte-Nelson, Heather (Thesis director) / Knight, George (Committee member) / Engler-Chiurrazzi, Elizabeth (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2015-05
Description
Hormone therapy (HT) containing 17beta-estradiol (E2) can greatly reduce physiological symptoms associated with declines in ovarian hormones that are seen with menopause. HT containing E2 has also been shown to play a beneficial role in cognitive function. There is discrepancy, however, surrounding which dose of E2 is the most optimal for cognition. A previous rodent behavioral study in our laboratory evaluated the effects of different doses of E2 on spatial memory performance, and results indicated that rats treated with a low E2 dose (0.3 g E2) made fewer working memory incorrect (WMI) errors, indicating enhanced spatial memory performance, compared to vehicle (0.1ml sesame oil)- and high E2 (3.0 g E2)- treated groups. This finding warranted the present investigation with the overarching aim to evaluate underlying neuromolecular mechanisms that may be modulating these cognitive effects. Both the insulin-like growth factor-1 receptor (IGF1-R) and extracellular regulated kinase (Erk) 2 have been observed to mediate E2-induced memory enhancements. We used the Western Blot to measure IGF1-R and activated Erk1/2 expression in brain regions involved in learning and memory, including the dorsal hippocampus, ventral CA1/CA2 hippocampus, entorhinal cortex, and perirhinal cortex. Results demonstrated a linear relationship between IGF1-R expression and administered E2 dose in the perirhinal cortex, whereby IGF1-R expression increased as the dose of E2 increased. Additionally, in the perirhinal cortex, IGF1-R expression tended to increase as activated Erk1 increased for all treatment groups. Further, number of WMI errors tended to decrease as IGF1-R expression and activated Erk1 expression in the perirhinal cortex tended to increase in the low E2 treatment group. Collectively, these findings suggest a downstream-dependent relationship between IGF1-R and activated Erk1 in the perirhinal cortex that may be contributing to the enhancements in spatial memory performance observed in animals in the low E2 treatment group. These findings are a crucial piece in the greater understanding of what underlying molecular mechanisms may be modulating a cognitively beneficial dose of E2, and further contribute to the search for a HT that would be beneficial for cognition in menopausal women.
ContributorsNeeley, Rachel Elizabeth (Author) / Bimonte-Nelson, Heather (Thesis director) / George, Andrew (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Previous studies have found that the detection of near-threshold stimuli is decreased immediately before movement and throughout movement production. This has been suggested to occur through the use of the internal forward model processing an efferent copy of the motor command and creating a prediction that is used to cancel out the resulting sensory feedback. Currently, there are no published accounts of the perception of tactile signals for motor tasks and contexts related to the lips during both speech planning and production. In this study, we measured the responsiveness of the somatosensory system during speech planning using light electrical stimulation below the lower lip by comparing perception during mixed speaking and silent reading conditions. Participants were asked to judge whether a constant near-threshold electrical stimulation (subject-specific intensity, 85% detected at rest) was present during different time points relative to an initial visual cue. In the speaking condition, participants overtly produced target words shown on a computer monitor. In the reading condition, participants read the same target words silently to themselves without any movement or sound. We found that detection of the stimulus was attenuated during speaking conditions while remaining at a constant level close to the perceptual threshold throughout the silent reading condition. Perceptual modulation was most intense during speech production and showed some attenuation just prior to speech production during the planning period of speech. This demonstrates that there is a significant decrease in the responsiveness of the somatosensory system during speech production as well as milliseconds before speech is even produced which has implications for speech disorders such as stuttering and schizophrenia with pronounced deficits in the somatosensory system.
ContributorsMcguffin, Brianna Jean (Author) / Daliri, Ayoub (Thesis director) / Liss, Julie (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Previous research has shown that a loud acoustic stimulus can trigger an individual's prepared movement plan. This movement response is referred to as a startle-evoked movement (SEM). SEM has been observed in the stroke survivor population where results have shown that SEM enhances single joint movements that are usually performed with difficulty. While the presence of SEM in the stroke survivor population advances scientific understanding of movement capabilities following a stroke, published studies using the SEM phenomenon only examined one joint. The ability of SEM to generate multi-jointed movements is understudied and consequently limits SEM as a potential therapy tool. In order to apply SEM as a therapy tool however, the biomechanics of the arm in multi-jointed movement planning and execution must be better understood. Thus, the objective of our study was to evaluate if SEM could elicit multi-joint reaching movements that were accurate in an unrestrained, two-dimensional workspace. Data was collected from ten subjects with no previous neck, arm, or brain injury. Each subject performed a reaching task to five Targets that were equally spaced in a semi-circle to create a two-dimensional workspace. The subject reached to each Target following a sequence of two non-startling acoustic stimuli cues: "Get Ready" and "Go". A loud acoustic stimuli was randomly substituted for the "Go" cue. We hypothesized that SEM is accessible and accurate for unrestricted multi-jointed reaching tasks in a functional workspace and is therefore independent of movement direction. Our results found that SEM is possible in all five Target directions. The probability of evoking SEM and the movement kinematics (i.e. total movement time, linear deviation, average velocity) to each Target are not statistically different. Thus, we conclude that SEM is possible in a functional workspace and is not dependent on where arm stability is maximized. Moreover, coordinated preparation and storage of a multi-jointed movement is indeed possible.
ContributorsOssanna, Meilin Ryan (Author) / Honeycutt, Claire (Thesis director) / Schaefer, Sydney (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial effects on cognition when given alone in a rodent model of menopause. However, it is unknown whether these hormones, when taken in combination, are beneficial or harmful to cognition. This is a critically important question given that these hormones are most often given in combination versus separately. This thesis is composed of two studies examining the cognitive effects of E2 and Levo using a rat model of surgical menopause. Study 1 assessed how the dose of E2 treatment in rats impacted cognitive performance, and found that low dose E2 enhanced working memory performance. Next, based on the results from Study 1, Study 2 used low dose E2 in combination with different doses of Levo to examine the cognitive effects of several E2 to Levo ratio combinations. The results from Study 2 demonstrated that the combination of low dose E2 with a high dose of Levo at a 1:2 ratio impaired cognition, and that the ratio currently used in HT, 3:1, may also negatively impact cognition. Indeed, there was a dose response effect indicating that working and reference memory performance was incrementally impaired as Levo dose increased. The findings in this thesis suggest that the E2 plus Levo combination is likely not neutral for cognitive function, and prompts further evaluation in menopausal women, as well as drug discovery research to optimize HT using highly controlled preclinical models.
ContributorsBerns-Leone, Claire Elizabeth (Co-author) / Prakapenka, Alesia (Co-author) / Pena, Veronica (Co-author) / Northup-Smith, Steven (Co-author) / Melikian, Ryan (Co-author) / Ladwig, Ducileia (Co-author) / Patel, Shruti (Co-author) / Croft, Corissa (Co-author) / Bimonte-Nelson, Heather (Thesis director) / Glenberg, Arthur (Committee member) / Conrad, Cheryl (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Motor skill acquisition, the process by which individuals practice and consolidate
movement to become faster, more accurate and efficient, declines with age. Initial skill acquisition is dominated by cortical structures; however as learning proceeds, literature from
rodents and songbirds suggests that there is a transition away from cortical execution. Recent
evidence indicates that the reticulospinal system plays an important role in integration and
retention of learned motor skills. The brainstem has known age-rated deficits including cell
shrinkage & death. Given the role of the reticulospinal system in skill acquisition and older
adult’s poor capacity to learn, it begs the question: are delays in the reticulospinal system
associated with older adult’s poor capacity to learn?
Our objective was to evaluate if delays in the reticulospinal system (measured via the
startle reflex) and corticospinal system (measured via Transcranial Magnetic Stimulation (TMS) are correlated to impairment of motor learning in older adults. We found that individuals with fast startle responses resembling those of younger adults show the most improvement and retention while individuals with delayed startle responses show the least. We also found that there was no relationship between MEP latencies and improvement and retention. Moreover, linear regression analysis indicated that startle onset latency exists within a continuum of learning outcomes suggesting that startle onset latency may be a sensitive measure to predict learning deficits in older adults. As there exists no method to determine an individual’s relative learning capacity, these results open the possibility of startle, which is an easy and inexpensive behavioral measure and can be used to determine learning deficits in older adults to facilitate better dosing during rehabilitation therapy.
movement to become faster, more accurate and efficient, declines with age. Initial skill acquisition is dominated by cortical structures; however as learning proceeds, literature from
rodents and songbirds suggests that there is a transition away from cortical execution. Recent
evidence indicates that the reticulospinal system plays an important role in integration and
retention of learned motor skills. The brainstem has known age-rated deficits including cell
shrinkage & death. Given the role of the reticulospinal system in skill acquisition and older
adult’s poor capacity to learn, it begs the question: are delays in the reticulospinal system
associated with older adult’s poor capacity to learn?
Our objective was to evaluate if delays in the reticulospinal system (measured via the
startle reflex) and corticospinal system (measured via Transcranial Magnetic Stimulation (TMS) are correlated to impairment of motor learning in older adults. We found that individuals with fast startle responses resembling those of younger adults show the most improvement and retention while individuals with delayed startle responses show the least. We also found that there was no relationship between MEP latencies and improvement and retention. Moreover, linear regression analysis indicated that startle onset latency exists within a continuum of learning outcomes suggesting that startle onset latency may be a sensitive measure to predict learning deficits in older adults. As there exists no method to determine an individual’s relative learning capacity, these results open the possibility of startle, which is an easy and inexpensive behavioral measure and can be used to determine learning deficits in older adults to facilitate better dosing during rehabilitation therapy.
ContributorsRangarajan, Vishvak (Author) / Honeycutt, Claire (Thesis director) / Schaefer, Sydney (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
There are currently no disease-modifying treatments to halt or attenuate the progression of Alzheimer’s disease (AD). Transgenic rodent models have provided researchers the ability to recapitulate particular pathological and symptomological events in disease progression. Complete reproduction of all features of AD in a rodent model has not been achieved, potentially lending to the inconclusive treatment results at the clinical level. Recently, the TgF344-AD transgenic rat model has started to be evaluated; however, it has not been well characterized in terms of its cognition, which is fundamental to understanding the trajectory of aging relative to pathology and learning and memory changes. Therefore, the aim of the current study was to identify cognitive outcomes at 6, 9, and 12 months of age in the TgF344-AD rat model. Sixty female transgenic (Tg) and wildtype (WT) rats were tested on the water radial arm maze, Morris water maze, and visible platform task to evaluate cognition. Results from the asymptotic phase of the water radial arm maze showed that the 6 mo-Tg animals had marginally impaired working memory compared to 6 mo-WT rats, and 12 mo-Tg rats had significantly impaired working memory compared to 12 mo-WT rats. The 9 mo-Tg animals did not demonstrate a significant difference in working memory errors compared to the 9 mo-WT animals. This pattern of impairment, wherein Tg animals made more working memory errors compared to WT animals at the 6 and 12 month time points, but not at the 9 month time point, may be indicative of an inflammatory response that proves helpful at incipient stages of disease progression but eventually leads to further cognitive impairment. These results provide insight into the potential earliest time point that prodromal cognitive symptoms of AD exist, and how they progress with aging. Brain tissue was collected at sacrifice for future analyses of pathology, which will be used to glean insight into the temporal progression of pathological and cognitive outcomes.
ContributorsBulen, Haidyn Leigh (Co-author) / Bulen, Haidyn (Co-author) / Bimonte-Nelson, Heather (Thesis director) / Presson, Clark (Committee member) / Conrad, Cheryl (Committee member) / Woner, Victoria (Committee member) / Peña, Veronica (Committee member) / School of International Letters and Cultures (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Motor skill acquisition, the process by which individuals practice and consolidate movement to become faster, more accurate and efficient, declines with age. Initial skill acquisition is dominated by cortical structures; however as learning proceeds, literature from rodents and songbirds suggests that there is a transition away from cortical execution. Recent evidence indicates that the reticulospinal system plays an important role in integration and retention of learned motor skills. The brainstem has known age-rated deficits including cell shrinkage & death. Given the role of the reticulospinal system in skill acquisition and older adult’s poor capacity to learn, it begs the question: are delays in the reticulospinal system associated with older adult’s poor capacity to learn?
Our objective was to evaluate if delays in the reticulospinal system (measured via the startle reflex) are correlated to impairment of motor learning in older adults. We found that individuals with fast startle responses resembling those of younger adults show the most learning and retention of that learning while individuals with delayed startle responses show the least. Moreover, linear regression analysis indicated that startle onset latency exists within a continuum of learning outcomes suggesting that startle onset latency may be a sensitive measure to predict learning deficits in older adults. As there exists no method to determine an individual’s relative learning capacity, these results open the possibility of startle, which is an easy and inexpensive behavioral measure, being used to predict learning deficits in older adults to facilitate better dosing during rehabilitation therapy.
Our objective was to evaluate if delays in the reticulospinal system (measured via the startle reflex) are correlated to impairment of motor learning in older adults. We found that individuals with fast startle responses resembling those of younger adults show the most learning and retention of that learning while individuals with delayed startle responses show the least. Moreover, linear regression analysis indicated that startle onset latency exists within a continuum of learning outcomes suggesting that startle onset latency may be a sensitive measure to predict learning deficits in older adults. As there exists no method to determine an individual’s relative learning capacity, these results open the possibility of startle, which is an easy and inexpensive behavioral measure, being used to predict learning deficits in older adults to facilitate better dosing during rehabilitation therapy.
ContributorsSchreiber, Joseph James (Author) / Honeycutt, Claire (Thesis director) / Schaefer, Sydney (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Age is the most significant risk factor for cancer development in humans. The somatic mutation theory postulates that the accumulation of genomic mutations over time results in cellular function degradation which plays an important role in understanding aging and cancer development. Specifically, degradation of the mechanisms that underlie somatic maintenance can occur due to decreased immune cell function and genomic responses to DNA damage. Research has shown that this degradation can lead to the accumulation of mutations that can cause cancer in humans. Despite recent advances in our understanding of cancer in non-human species, how this risk factor translates across species is poorly characterized. Here, we analyze a veterinarian cancer dataset of 4,178 animals to investigate if age related cancer prevalence is similar in non-human animals. We intend for this work to be used as a primary step towards understanding the potential overlap and/or uniqueness between human and non-human cancer risk factors. This study can be used to better understand cancer development and how evolutionary processes have shaped somatic maintenance across species.
ContributorsAksoy, Selin (Author) / Maley, Carlo (Thesis director) / Boddy, Amy (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Department of Psychology (Contributor)
Created2022-05
Description
Aging is a universal process that every being encounters on their journey of life. The effect of dance as a form of improvement of physical and well-being on the aging body brings upon the question of the impact of somatic-based movement, specifically gestural movement on the perceptions of aging within older and younger adults through a bi-cultural lens of the United States and India. This was investigated using a series of creative partnership workshops that included listening, drawing, and culminating movement activities, followed by a group discussion about the creative process. There were four different participant groups: a group of college students taking an Aging in American Culture collegiate class, a Somatic Practices collegiate dance class, a group of older adults at the Tempe Multigenerational Center, and a group of older adults in Bangalore, India. Inter-generational and cross-cultural observations were discussed, and it was seen that the workshops were able to foster feelings of community and camaraderie among participants depending on the group’s relationship to dance-making. From the research, a dance performance was developed and performed specifically with women of color in ASU’s Dance program with the choreographic process discussed in detail, along with key takeaways about facilitating a multi-dimensional experience for the dancers and choreographer. Future directions for the work include working with intergenerational populations and researching community effects on gendered aging experiences across cultures in the dance world.
ContributorsDabeer, Shreya (Author) / Fitzgerald, Mary (Thesis director) / Standley, Eileen (Committee member) / Barrett, The Honors College (Contributor) / School of Music, Dance and Theatre (Contributor) / Department of Psychology (Contributor)
Created2022-05