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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, …

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 …

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 …

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) …