Behavioral Neurobiology Commons^™

How To Search For The Engram: Optogenetics And Network Dynamics, Claudia Garcia Jou

Dissertations, Theses, and Capstone Projects

Memories are thought to be encoded by ensembles of neurons called "engram cells", because their artificial activation with optogenetics leads to the behavioral expression of a memory. However, the physiological mechanisms that mediate this process remain unknown. In this thesis, I investigate how optogenetic stimulation of memory-tagged cells changes neuronal firing, spatial coding, and the geometry of neural manifolds. I used an active place avoidance task and a foraging task to label engram cells in the dorsal hippocampus with Channelrhodopsin2 (ChR2). I then recorded the hippocampal activity response to optogenetic stimulation in mice under anesthesia, head-fixed, or freely moving. I …

A Natural Short Sleep Mutation Promotes Longevity Through Mitochondrial Respiration In Drosophila, Pritika Pandey

LSU Doctoral Dissertations

Aging is an irreversible process characterized by progressive physiological decline and an increased risk of metabolic disorders, cognitive impairment, cardiovascular diseases, and neurodegeneration. Disruptions to the circadian clock—whether due to genetic mutations or behavioral factors—accelerate aging and age-related pathologies, highlighting a strong link between circadian regulation and longevity. However, certain individuals harbor a dec2^P384R mutation, which enables natural short sleep without the detrimental effects of chronic sleep deprivation. This suggests that these individuals have evolved adaptations that activate pro-health pathways, allowing them to function optimally with reduced sleep. To investigate the genetic mechanisms underlying these changes, we developed a …

Hippocampal Insulin Exists! In Vivo Sampling Methods, Basal Concentrations, Recurrent Hypoglycemia, And Behavioral Extracellular Insulin Responses, Starlette R. Douglass

Electronic Theses & Dissertations (2024 - present)

Insulin has widespread actions within the brain, including energy homeostasis, modulation of feeding, and as a key component of memory processes. Further, brain insulin dysfunction correlates with Alzheimer's disease and other neurodegenerative disorders. To this point, measurement of hippocampal insulin has been limited. Determining in vivo hippocampal insulin levels both at a healthy baseline and after, e.g., induction of a disease state or in response to cognitive challenge, is essential to advance our understanding of both insulin's procognitive actions and to guide potential therapeutic interventions.

We first sought to establish a sampling technique for insulin within awake and moving rats …

Consequences Of Environment And Loss On Maternal Behavior, Anxiety, Boldness, And Memory In Rats, Alayna Skye Palamar

Longwood Senior Thesis Proposal

No abstract provided.

The Effects Of Floral Attributes And Conspecifics On Bumble Bee Forager Memory, Lucas Lauter, Tiffany Dinh

Undergraduate Research Symposium

What do bees remember about flowers? These memories are important for both bees and flowers. The bees have better foraging success and gain more nectar and pollen from flowers when they remember the most rewarding flower types. More memorable flowers will be visited more frequently, resulting in more successful pollination for the plant. At the same time, bees can also learn about flowers from other bees and may remember this information differently. We are training and testing three floral cues and a single social cue to see how the different types of cues affect their learning and memory of rewarding …

Interhemispheric Communication And Lateralization In The Mouse Hippocampus, Jake Jordan

Dissertations, Theses, and Capstone Projects

The hippocampus is essential for memory and spatial navigation. Many theories have been proposed to explain how the hippocampus contributes to cognition; however, none has fully explained relevant neurophysiological and behavioral data. Hemispheric lateralization of hippocampal function has been reported in humans and in rodents, and lateralization of hippocampal neural circuitry has been reported in rodents. Most theories of hippocampal function fail to consider the hippocampus as a bilateral structure with hemispheric differences. Further, proposed theories of hippocampal lateralization have their own limitations in explaining empirical data concerning left/right function. Little is known about communication between the hippocampi across hemispheres. …

Behavioral And Molecular Analysis Of Memory In The Dwarf Cuttlefish, Jessica M. Bowers

College of Graduate Studies: Theses & Dissertations

Complex memory has evolved because it benefits animals in all areas of life, such as remembering the location of food or conspecifics, and learning to avoid dangerous stimuli. Advances made by studying relatively simple nervous systems, such as those in gastropod mollusks, can now be used to study mechanisms of memory in more complex systems. Cephalopods offer a unique opportunity to study the mechanisms of memory in a complex invertebrates. The dwarf cuttlefish, Sepia bandensis, is a useful memory model because its fast development and small size allows it to be reared and tested in large numbers. However, primary literature …

Contextual Fear Memory Modulates Psd95 Phosphorylation, Ampar Subunits, Pkmζ And Pi3k Differentially Between Adult And Juvenile Rats, Roseanna M. Zanca, Shirley Sanay, Jorge A. Avila, Edgar Rodriguez, Harry N. Shair, Peter A. Serrano

Publications and Research

It is well known that young organisms do not maintain memories as long as adults, but the mechanisms for this ontogenetic difference are undetermined. Previous work has revealed that the α-amino-3-hydroxy-5-methyl-4isoxazolepropionic acidreceptor (AMPAr)subunits aretraffickedinto the synaptic membranefollowing memory retrieval in adults. Additionally, phosphorylated PSD-95-pS295 promotes AMPAr stabilization at the synapse. We investigated these plasticity related proteins as potential mediators in the differential contextual stress memory retrieval capabilities observed between adult and juvenile rats. Rats were assigned to either pedestal stress (1h) or no stress control (home cage). Each animal was placed alone in an open field for 5minat the base …

Defining The Radioresponse Of Mossy Cells, Devon Ivy

Electronic Theses, Projects, and Dissertations

Clinical radiotherapy is used to treat a variety of brain tumors within the central nervous system. While effective, it can result in progressive and debilitating cognitive impairment that can diminish quality of life. These impairments have been linked to hippocampal dysfunction and corresponding deficits in spatial learning and memory. Mossy cells are a major population of excitatory neurons located within the dentate hilus and highly involved in hippocampal circuitry. They play critical roles in spatial navigation, neurogenesis, memory, and are particularly vulnerable to a variety of neurotoxic insults. However, their sensitivity to ionizing radiation has yet to be investigated in …

Moderate Prenatal Alcohol Exposure Impairs Performance In An Object-Place-Paired-Associate Task, Lilliana May Sanchez

Psychology ETDs

Memory impairments, including spatial and object processing, are often observed in individuals with Fetal Alcohol Spectrum Disorder. Much attention has been directed towards the hippocampus, which displays significant alterations after moderate prenatal alcohol exposure (PAE). In the present study, we tested a moderate PAE rat model in an object-place-paired-associate (OPPA) task, previously shown to require hippocampal processing. The OPPA task was composed of training rats to discriminate between an identical pair of objects presented in 180° opposite arms of a radial arm maze. Animals were given a total of 10 trials per day over 14 consecutive days of training and …

A Behavioral And Neuroimmune System Model Of The Effects Of Chronic Low-Level Lead Exposure In Young Male C57bl/6j Mice, Mayra Gisel Flores-Montoya

Open Access Theses & Dissertations

Chronic low-level lead exposure reduces memory in children however the brain mechanisms mediating these effects are not known. In previous studies we showed that early lead exposure reduced olfactory memory and exploratory behavior in young mice, and reduced microglia cell density in hippocampus/dentate gyrus. The present studies aimed to identify additional behavioral tests that were sensitive to early low-level lead exposure in young mice; and to examine whether microglia upregulated factors known to promote cell migration. Seventy-two C57BL/6J male mice were exposed to 0 ppm (controls), 30 ppm (low-dose), or 430 ppm (high-dose) of lead acetate via dams' milk from …

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 …

The Effects Of Lipopolysaccharide-Induced Neuroinflammation On Learning And Forgetting In Juvenile Rats, Michele Barry

Seton Hall University Dissertations and Theses (ETDs)

The inability to remember events experienced very early in life is referred to as Infantile Amnesia (IA) and has been observed in both humans and animals. Over the years interest in the phenomenon waned, but has recently increased with the discovery of new neurobiological methods to study brain function (e.g., Callaghan, Li & Richardson, 2014). The neurobiological mechanism behind IA has yet to be determined, but several innovative theories have been developed with these new research methods. The neurogenesis hypothesis theorizes that increased neurogenesis during early development disrupts previously established memories. The hippocampus, an area that mediates both the memory …

Mtorc1 Signaling In Memory Formation And Dysfunction, Natalia S. Rozas De O'Laughlin

Dissertations and Theses (Open Access)

The mechanistic Target of Rapamycin Complex 1 (mTORC1) pathway integrates cellular availability of growth factors, energy and amino acids to regulate protein synthesis and autophagy. The mTORC1 pathway has also been shown to be required for memory consolidation, and its dysregulation is associated with many neurological disorders. MTORC1 is negatively regulated by the tuberous sclerosis complex (TSC1/2). When ATP and growth factors are available, TSC1/2 is inhibited and mTORC1 activity can be restored. In a complementary regulatory pathway, amino acids signal to mTORC1 through the Rag GTPases and Ragulator complex, which modulate the translocation of mTORC1 from the cytoplasm to …

Norepinephrine Involvement In The Intermittent Swim Stress-Induced Deficit In Spatial Learning And Memory, Emily Elgert

Honors Theses and Capstones

Learning and memory impairments are often caused by stress disorders including depression. The present study investigated the involvement of norepinephrine in the swim stress-induced deficits of spatial learning and memory. Exposure to intermittent swim stress (ISS) followed by learning and memory tests in the Morris water maze (MWM) were used to investigate this relationship. The ISS paradigm consists of intermittent exposure to cold water, producing stress responses in rats. Reboxetine, a norepinephrine selective reuptake inhibitor (NSRI), was employed to investigate whether this compound reverses the ISS-induced deficit. In other words, rats exposed to the ISS, were hypothesized to experience impaired …

Ethanol Reward Conditioning In Drosophila Melanogaster, Isaac A. Moya^, Young-Cho Kim, Kyung-An Han*

COURI Symposium Abstracts, Spring 2012

No abstract provided.