Life Sciences Commons^™

The Role Of Glutamate In The Medial Prefrontal Cortex In The Acquistion And Expression Of Conditioned Approach, Rudolf Nisanov

Dissertations, Theses, and Capstone Projects

A series of experiments were conducted to assess the role of glutamatergic stimulation in the dorsal and ventral regions of the medial prefrontal cortex (mPFC) in both the acquisition and expression of reward-related learning using a Pavlovian conditioning paradigm, the conditioned-approach paradigm. Rats with surgically implanted cannulas were exposed to Pavlovian conditioning sessions that occurred on three alternative days (acquisition) or seven consecutive days (expression). These 60-min conditioning sessions consisted of 30 pairings of light (CS) and food pellets (US) presented under a random time schedule. After a two-day break, rats underwent a session with no CS or US and …

Brainwaves, Memory, And Reward, Rebecca Mccune

Dissertations, Theses, and Capstone Projects

The development of effective educational curricula for enhancing learning involves the crucial consideration of effort and rewards. In the realm of education, teachers commonly employ rewards as motivational tools. Traditionally, these rewards are given to students as a recognition of their successful performance. However, a thought-provoking idea emerges: What if we were to extend rewards to students not solely based on accurate answers, but also on the effort they invest, even in cases where their actual response might be incorrect? Our study explores the potential impact of this approach on the way information is absorbed and subsequently retained, specifically focusing …

Testing An Overtraining Protocol For Fear Learning In Humans, Gordon M. Haskell

Dissertations, Theses, and Capstone Projects

Successful regulation of fear memories is a fundamental tenet to the exposure-based therapies often employed by mental health professionals for individuals with PTSD, phobias, and other anxiety disorders. Consequently, the efficacy of these treatment methodologies is largely dependent on the strength of the fear memory, as stronger memories are often characterized by an increased resistance to extinction and heightened fear recovery. However, there is little consensus within the scientific community regarding how to effectively maximize fear memory strength in human studies, and the literature exploring the impact of variability in acquisition parameters on memory strength is sparse. Here, we tested …

Contributions Of Reward Identity And Time Prediction Errors To Pavlovian Learning, Daniel B. Siegel

Dissertations, Theses, and Capstone Projects

Some models of associative learning attempt to explain effects such as blocking and unblocking as reflecting a prediction error (PE): Associative strength, and thereby learning, are said to be greater when the unconditioned stimulus (US) received following a cue deviates from one’s expectations. Some models of PE-motivated behavior and PE-relevant brain activity represent the US as a single quantitative variable for outcome value, and that learning therefore only occurs when outcome value differs from expectations. There is growing evidence to suggest that changes in other dimensions of reward, such as identity and timing, also contribute to learning. In Experiment 1, …

The Neural Correlates Of Cued Reward Omission, Jessica A. Mollick, Luke J. Change, Anjali Krishnan, Thomas E. Hazy, Kai A. Krueger, Guido K. W. Frank, Tor D. Wager, Randall C. O'Reilly

Publications and Research

Compared to our understanding of positive prediction error signals occurring due to unexpected reward outcomes, less is known about the neural circuitry in humans that drives negative prediction errors during omission of expected rewards. While classical learning theories such as Rescorla–Wagner or temporal difference learning suggest that both types of prediction errors result from a simple subtraction, there has been recent evidence suggesting that different brain regions provide input to dopamine neurons which contributes to specific components of this prediction error computation. Here, we focus on the brain regions responding to negative prediction error signals, which has been well-established in …

Experience-Dependent Changes In Nucleus Accumbens Activity Predict Cued Approach Learning: Contribution Of Nmda Receptors, Mercedes Vega Villar

Dissertations, Theses, and Capstone Projects

Animals learn associations between environmental cues and the natural rewards they predict (e.g., food, water, sex). As a result, reward-predictive cues come to trigger vigorous reward-seeking responses. Many neurons in the nucleus accumbens (NAc) become excited upon presentation of an already-learned reward-predictive cue. These NAc responses encode the motivational value of the cue and are necessary for the expression of the subsequent approach behavior. However, the precise temporal relationship between the emergence of cue-evoked excitations in the NAc and the acquisition of cued approach behavior remains unknown. In Experiment 1, NAc activity was recorded as rats learned to approach a …

Effects Of Weak Electric Fields On Long-Term Synaptic Plasticity, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a technique where a weak direct electrical current is applied to the scalp with the goal of stimulating the brain. There is tremendous interest in the use of tDCS for treating brain disorders and improving brain function. However, the effects of tDCS have been highly variable across studies, leading to a debate over its efficacy. A major challenge is therefore to design tDCS protocols that yield predictable effects, which will require a better understanding of its basic mechanisms of action. One commonly discussed mechanism is that tDCS may alter synaptic plasticity, but the biophysics …

Combined Mnemonic Strategy Training And High-Definition Transcranial Direct Current Stimulation For Memory Deficits In Mild Cognitive Impairment, Benjamin M. Hampstead, Krishnankutty Sathian, Marom Bikson, Anthony Y. Stringer

Publications and Research

Introduction: Memory deficits characterize Alzheimer’s dementia and the clinical precursor stage known as mild cognitive impairment. Nonpharmacologic interventions hold promise for enhancing functioning in these patients, potentially delaying functional impairment that denotes transition to dementia. Previous findings revealed that mnemonic strategy training (MST) enhances long-term retention of trained stimuli and is accompanied by increased blood oxygen level–dependent signal in the lateral frontal and parietal cortices as well as in the hippocampus. The present study was designed to enhance MST generalization, and the range of patients who benefit, via concurrent delivery of transcranial direct current stimulation (tDCS).

Methods: This protocol describes …

Adult Neurogenesis In Avian Auditory Cortex, Caudomedial Nidopallium (Ncm): Lateralization And Effects Of Statins, Shuk C. Tsoi

Dissertations, Theses, and Capstone Projects

In the first part of this paper, we investigated the basic relationship between learning, memory and adult neurogenesis using zebra finches. We found that in the auditory cortex, the left hemisphere had more new neurons than the right hemisphere. This lateralization was correlated with song learning and memory. In the second part, we used juvenile zebra finches as a model organism to study the effects of Lipitor on learning, memory and neurogenesis. We found that Lipitor impaired song learning and memory storage. Lipitor treatments also changed the morphology of new neurons and size of old neurons, suggesting statins may affect …

Does Cognitive Impairment Affect Rehabilitation Outcome In Parkinson’S Disease?, Davide Ferrazzoli, Paola Ortelli, Roberto Maestri, Rossana Bera, Nir Giladi, Maria Felice Ghilardi, Gianni Pezzoli, Giusseppe Frazzitta

Publications and Research

Background: The cognitive status is generally considered as a major determinant of rehabilitation outcome in Parkinson’s disease (PD). No studies about the effect of cognitive impairment on motor rehabilitation outcomes in PD have been performed before.

Objective: This study is aimed to evaluate the impact of cognitive decline on rehabilitation outcomes in patients with PD.

Methods: We retrospectively identified 485 patients with PD hospitalized for a 4-week Multidisciplinary Intensive Rehabilitation Treatment (MIRT) between January 2014 and September 2015. According to Mini Mental State Examination (MMSE), patients were divided into: group 1—normal cognition (score 27–30), group 2—mild cognitive …

Training A New Trick Using No-Reward Markers: Effects On Dogs’ Performance And Stress Behaviors, Naomi Rotenberg

Theses and Dissertations

This study explored using no-reward markers (NRMs). Dogs were taught a novel trick. In the IG group dogs’ errors were ignored; in the NRM group they elicited a tone. Performance and stress were evaluated. IG dogs reached higher levels of performance, with no difference in the frequency of stress behaviors.

Behavioral And Cognitive Changes After Early Postnatal Lesions Of The Rat Mediodorsal Thalamus, Zakaria Ouhaz, Saadua B-M'Hamed, Anna S. Mitchell, Abdeslem Elidrissi, Mohamed Bennis

Publications and Research

Early insults to the thalamus result in functional and/or structural abnormalities in the cerebral cortex. However, differences in behavioral and cognitive changes after early insult are not well characterized. The present study assessed whether early postnatal damage to mediodorsal nucleus of the thalamus (MD), reciprocally interconnected with the prefrontal cortex, causes behavioral and cognitive alterations in young adult rats. Rat pups at postnatal day 4 received bilateral electrolytic lesion of MD, or aMD Sham lesion or were anesthetized controls; on recovery they were returned to their mothers until weaning. Seven weeks later, all rats were tested with the following behavioral …

Roles Of Dopamine D1 And D2, Opioid And Glutamate Nmda Receptor Signaling In The Acquisition And Expression Of Fat- And Glucose-Conditioned Flavor Preferences In Rats And C-Fos Analysis Of The Dopamine Mesotelencephalic And Nigrostriatal Pathways Following Intake Of Sugars And Fats In Rats, Julie Dela Cruz

Dissertations, Theses, and Capstone Projects

Systemic administration of the non-competitive NMDA antagonist, MK-801, demonstrated that acquisition, but not expression, were found to affect the orosensory-mediated (flavor/flavor: f/f) fructose-conditioned flavor preference (CFP). The present studies demonstrated a similar outcome when f/f and f/n processes were combined. Fat-CFP and glucose-CFP studies indicated that systemic injections of the NMDA antagonist, MK-801, were able to significantly reduce acquisition, but not expression, of Corn-Oil (CO)-CFP and glucose-CFP. Both studies appear to have mitigated effects on acquisition as compared to the separate orosensory and postingestive CFP studies.

Previous studies found that systemic administration of dopamine (DA) D1 (SCH23390) and D2 (raclopride) …

Does Increasing Biology Teacher Knowledge Of Evolution And The Nature Of Science Lead To Greater Advocacy For The Teaching Of Evolution In Schools?, Ross Nehm, Irvin Sam Schonfeld

Publications and Research

This study investigated whether or not an increase in secondary science teacher knowledge about evolution and the nature of science gained from completing a graduate-level evolution course was associated with greater preference for the teaching of evolution in schools. Forty-four precertified secondary biology teachers participated in a 14-week intervention designed to address documented misconceptions identified by a precourse instrument. The course produced statistically significant gains in teacher knowledge of evolution and the nature of science and a significant decrease in misconceptions about evolution and natural selection. Nevertheless, teachers' postcourse preference positions remained unchanged; the majority of science teachers still preferred …