Matching Items (4)
Description
In this paper, it is determined that learning retention decreases with age and there is a linear rate of decrease. In this study, four male Long-Evans Rats were used. The rats were each trained in 4 different tasks throughout their lifetime, using a food reward as motivation to work. Rats were said to have learned a task at the age when they received the highest accuracy during a task. A regression of learning retention was created for the set of studied rats: Learning Retention = 112.9 \u2014 0.085919 x (Age at End of Task), indicating that learning retention decreases at a linear rate, although rats have different rates of decrease of learning retention. The presence of behavioral training was determined not to have a positive impact on this rate. In behavioral studies, there were statistically significant differences between timid/outgoing and large ball ability between W12 and Z12. Rat W12 had overall better learning retention and also was more compliant, did not resist being picked up and traveled more frequently at high speeds (in the large ball) than Z12. Further potential studies include implanting an electrode into the frontal cortex in order to compare neuro feedback with learning retention, and using human subjects to find the rate of decrease in learning retention. The implication of this study, if also true for human subjects, is that older persons may need enhanced training or additional refresher training in order to retain information that is learned at a later age.
ContributorsSpinrad, Amelia (Author) / Si, Jennie (Thesis director) / Thompson, Patrick (Committee member) / Ma, Weichao (Committee member) / Barrett, The Honors College (Contributor)
Created2014-05
Description
Drospirenone (DRSP) is a novel, pharmacologically unique synthetic progestin with properties more similar to the endogenous progestogen, progesterone, than any other progestin currently on the market. While a significant amount of research has been conducted on the risks associated with DRSP, the impact of DRSP on cognition, especially in reference to learning and memory, is not well understood. However, it is imperative to fully understand the cognitive effects of DRSP, both alone and in combination with EE (as taken in a combined oral contraceptive [COC]), so that women and their physicians can make a fully-informed decision when deciding to take a DRSP-containing COC. Study 1 examined the effects of three doses of DRSP in order to determine the optimal dose for combining with EE, and found that the medium dose of DRSP (30 µg/day) enhanced spatial working memory performance. In Study 2, the medium dose of DRSP from Study 1 was combined with low (0.125 µg/day) and high (0.3 µg/day) doses of EE to examine the effects of DRSP as taken with EE in a COC. The results from Study 2 indicated that when DRSP was combined with a low, but not high, dose of EE, spatial working memory impairments were seen at the highest working memory load. Anxiety-like behavior was evaluated using the OFT, and DRSP was shown to decrease measures of anxiety-like behavior. Additionally, while treatment with a high dose of EE decreased several measures of anxiety-like behavior, a low dose of EE did not, suggestive of a dose response. Taken together, the findings presented from both studies suggest that some of the cognitive effects of the combination of DRSP with EE are different than those of either hormone administered on its own. Further exploration in a preclinical, ovary-intact animal model is a next step to fully understand these effects in the translational context of a contraceptive, given that women taking an EE-DRSP combination are typically ovary-intact.
ContributorsPoisson, Mallori Louise (Author) / Bimonte-Nelson, Heather (Thesis director) / Doane, Leah (Committee member) / School of Nutrition and Health Promotion (Contributor) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The mammalian target of rapamycin (mTOR) is integral in regulating cell growth as it maintains a homeostatic balance of proteins by modulating their synthesis and degradation. In the brain, mTOR regulates protein-driven neuroplastic changes that modulate learning and memory. Nevertheless, upregulation of mTOR can cause detrimental effect in spatial memory and synaptic plasticity. The proline-rich Akt-substrate 40 kDa (PRAS40) is a key negative regulator of mTOR, as it binds mTOR and directly reduces its activity. To investigate the role of PRAS40 on learning and memory, we generated a transgenic mouse model in which we used the tetracycline-off system to regulate the expression of PRAS40 specifically in neurons of the hippocampus. After induction, we found that mice overexpressing PRAS40 performed better than control mice in the Morris Water Maze behavioral test. We further show that the improvement in memory was associated with a decrease in mTOR signaling, an increase in dendritic spines in hippocampal pyramidal neurons, and an increase in the levels of brain-derived neurotrophic factor (BDNF), a neurotrophin necessary for learning and memory. This is the first evidence that shows that increasing PRAS40 in the mouse brain enhances learning and memory deficits.
ContributorsSarette, Patrick William (Author) / Oddo, Salvatore (Thesis director) / Caccamo, Antonella (Committee member) / Kelleher, Raymond (Committee member) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The need to fully understand the possible consequences of young-adult cannabis use has become increasingly critical as a result of major cannabis policy changes. The purpose of this study was to determine if young-adult users exhibit cognitive deficits on laboratory-based tests and memory and attention deficits in everyday life. Participants were 152 students from a large U.S. university enrolled in introductory psychology courses and the top and bottom 10% of the 12-item Yale University PRIME Screening Test for psychotic-like experiences. Participants were asked about their cannabis use and were given six cognitive tests spanning executive function and memory. To test functional impairment in memory and attention, participants were asked to nominate informants (people who knew them well) and these rated the participants on an attention problems scale of four items and a memory problems scale of three items. Results showed that individuals who used cannabis more frequently were rated as having more attention and memory problems and that, consistent with prior research, more frequent cannabis use was associated with worse memory test performance, though the association was not present between frequency of use and executive function test performance. Additionally, it was found that informant-reported attention problems were associated with poorer performance on two of the executive function cognitive tests. The present findings suggest that individuals who use cannabis more frequently experience noticeable memory and attention problems in everyday life, despite the lack of significant correlation between this functional impairment and cognitive test performance. Informant reports, therefore, may be useful in future research for understanding or predicting cognitive impairment in young adults.
ContributorsCarbajal, Lucia (Author) / Meier, Madeline (Thesis director) / McClure, Samuel (Committee member) / Department of Psychology (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12