Lecture 4- Learning & Memory 2 Flashcards
What is nondeclarative, or procedural, memory, and what kinds of information fall under this category?
Nondeclarative, or procedural, memory includes unconsciously acquired and retrieved information, such as motor skills, classical conditioning, priming effects, and puzzle solving skills.
Phylogenetic Memory
Iherited genetic knowledge and instincts passed down through generations of a species.
Priming Effect
exposure to one stimulus influences the response to another stimulus, often leading to increased accessibility or processing speed of related information.
Skinner Box
The most common method for studying operant conditioning, involved placing a rodent in a controlled environment to study how they learn behaviors through rewards and punishments
A clinical case study of H.M.’s brain after a bilateral medial temporal lobe resection (removal of amygdala, uncus, hippocampal gryus, anterior two-third of hippocampus) revealed impairment to what type of memory?
A.) anterograde
B.) retrograde
C.) nondeclarative
D.) Both A and B
A.) anterograde; inability to form new memories after an event or injury, while past memories remain intact.
A clinical case study of K.C.’s brain after bilateral hippocampal and parahippocampal damage revealed impairment to what type of memory?
A.) anterograde
B.) retrograde
C.) nondeclarative
D.) Both A and B
D) Anterograde and retrograde. He was unable to retrieve personal memories from his past (retrograde amnesia) and also unable to form new episodic memories (anterograde amnesia) after his accident. However, his ability to form new semantic memories and learn new skills was preserved.
What is the role of the limbic circle in memory?
The limbic circle is a neural circuit that connects various brain centers, including the hippocampus, amygdala, and thalamus, crucial for forming declarative memories.
What function does the fornix serve in the limbic system?
The fornix is a fiber tract that carries information from the hippocampus to the mammillary bodies, facilitating memory formation.
What is a characteristic of short-term memory in terms of stability?
Short-term memory is labile, meaning it is sensitive to disruption.
What are the hallmarks of Alzheimer’s disease in the brain?
Neurofibrillary tangles and amyloid plaques, particularly dense in the hippocampus, are hallmarks of Alzheimer’s disease, indicating neuron degradation.
How does the Morris water maze demonstrate the role of the hippocampus in memory?
The Morris water maze shows that the hippocampus is essential for spatial learning and memory in rodents, as damage to this area impairs the ability to navigate the maze
How is the protein Arc involved in synaptic plasticity?
Arc binds to the cytoskeletal protein actin in dendritic spines, playing a key role in synaptic plasticity and memory processes like long-term potentiation (LTP).
Does short-term memory require new RNA or protein synthesis?
No, short-term memory does not require new RNA or protein synthesis.
What does it mean for long-term memory to be consolidated?
Consolidation means that long-term memory becomes insensitive to disruption over time.
Does long-term memory formation involve new RNA or protein synthesis?
Yes, long-term memory formation requires new RNA or protein synthesis
Amygdala Functions
1)Emotional memory
2) Motor Response
3) Decision Making
4) Social Cognition
5) Awareness
6) Salience Detection
Where is the hippocampus located in relation to the lateral ventricle?
The hippocampus is located on the medial wall of the lateral ventricle.
Which nerve fibers are located proximal to the mammillary body?
The optic nerve fibers are located proximal to the mammillary body.
Pathway of the Trisynaptic Circuit
- Granule cells in dentate gyrus send axons (mossy fibers) to excite CA3 pyramidal cells.
- CA3 pyramidal cells send axons (Schaffer collaterals) to contact neurons in CA1.
- CA1 pyramidal cells continue relaying information to other limbic system and cortical regions, facilitating information processing within the hippocampal circuitry.
Explain the Hippocampus Circuity
Information enters the hippocampus from the entorhinal cortex, which includes the medial and lateral entorhinal cortex.
The subiculum acts as a relay station, forwarding information from the entorhinal cortex to the hippocampus proper.
Information from the dentate gyrus travels to the CA3 region through mossy fibers and then to CA1 via Schaffer collaterals.
Processed information exits the hippocampus through a structure called the fimbria of the fornix and connects with other brain regions in the limbic system, such as the amygdala.
Where does the hippocampus receive its information from?
The hippocampus receives its information from the entorhinal cortex, including both the medial and lateral entorhinal cortex.
What role does the subiculum play in the hippocampal circuitry?
The subiculum acts as a relay station, sending information from the entorhinal cortex to the rest of the hippocampus.
How is information transmitted within the hippocampus?
Information is transmitted from the dentate gyrus to the CA3 region via mossy fibers and then to CA1 via Schaffer collaterals.
How does information processed in the hippocampus reach other brain regions?
Processed information exits the hippocampus through the fimbria of the fornix and links to other regions in the limbic system, such as the amygdala.
Which proteins are influenced by CREB’s transcriptional activity?
CREB influences the transcription of proteins like brain-derived neurotrophic factors (BDNF) and activity-regulated cytoskeleton-associated protein (Arc).
How do Fos and c-Fos function as markers in memory research?
Fos and c-Fos serve as early indicators of neuronal activity during memory formation and modification.
When are immediate early genes like Fos and c-Fos typically activated?
Immediate early genes are activated shortly after synaptic activity, indicating the start of new memory encoding or alteration.
Describe the relationship between kinase pathways and memory mechanisms.
Kinase pathways, through phosphorylation, activate CREB and other transcription factors, initiating gene expression linked to memory formation.
What molecular changes occur in neurons during learning?
Learning triggers kinase pathways that lead to gene expression and synaptic changes in neurons, forming the basis of memory encoding.
What is the function of Arc protein in dendritic spines?
Arc binds to F-actin, a structural protein of dendritic spines, helping to helps stabilize and transport proteins in dendritic spines
How does Arc influence synaptic changes associated with learning?
Arc controls the removal and addition of AMPA receptors at synapses, leading to weakening (LTD) or strengthening (LTP) of synaptic connections.
What is the Morris water maze test designed to evaluate in rodents?
The Morris water maze test evaluates spatial learning and memory, requiring rodents to locate a hidden platform in a tank using environmental cues.
What effect do hippocampal lesions have on rodents in the Morris water maze?
Rodents with hippocampal lesions show impaired learning and memory as they fail to remember the platform’s location, indicating the hippocampus’s critical role in this process.
Lesions of varying size and location were made in rat brains either before or after the animals had learned to run mazes of varying complexity. Which of the following conclusions can be made based on the results of the experiment?
A.) The amount of tissue destroyed was proportional to learning reduction
B.) Tissue location was inconsequential in learning reduction (it didn’t matter where the damage occured, the impact was similar)
C.) lesions were more likely to reduce performance for complex tasks
What type of memories are included in declarative memory?
Declarative memory includes daily episodes, words and their meanings, and history.
Difference between declarative and non-declarative memory
Declarative memory involves information that can be consciously recalled, such as facts and events, while nondeclarative memory involves skills and actions that are performed without conscious awareness.
SA: What lines of evidence support the proposal that declarative memory and procedural memory
involve different brain mechanisms?
Evidence from patients like H.M., N.A., and R.B., who had damage to their hippocampus, had deficits in declarative memory but could still learn new skills (procedural memory). This suggests different parts of the brain handle these types of memory.
SA: What has patient H.M. taught us about human memory?
Patient H.M. had damage to his medial temporal lobe. After surgery, he couldn’t form short-term memories, but he retained the ability to recall
information and events from before his surgery, so his long-term memory was intact. He could also learn new skills like playing the piano, suggesting long-term and procedural memory are managed by brain regions other than the medial temporal lobe.
SA: What approaches are used to assess hippocampal involvement in memory consolidation?
The role of the hippocampus in memory formation can be assessed in different ways.
1. Examining patients that have hippocampus damage or using fMRI to scan healthy subjects can
give insight into hippocampal function.
2. Additionally, lesion studies in laboratory animals allow
observation of the effects of damage to specific locations
SA:Which evidence suggests that short-term and long-term memory involve different brain
mechanisms?
In addiiton to retaining their procedural memory, H.M., N.A., and R.B. retained old memories formed prior to their injury but struggled to form new ones, showing only anterograde amnesia. Hippocampal damage impacts short-term, not long-term memory storage.
2. Additionally loss of cortical regions and techniques like electroconvulsive therapy can cause retrograde amnesia, suggesting long-term memory storage happens in the cortex.
SA: What are the neural and behavioral symptoms of Alzheimer’s disease? Briefly summarize the
current view on the causes of Alzheimer’s disease
Neural symptoms: Presence of neurofibrillary tangles, amyloid-beta plaques, and a
loss of neurons
Behavioural Symptoms: Memory problems, language deficits, spatial issues, and personality changes.
Cause: The cause is unclear, but genetic mutations like in amyloid precursor protein, presenilin 1, and presenilin 2 are linked to early-onset Alzheimer’s. The e4 allele of the ApoE gene raises late-onset Alzheimer’s risk.
SA: What changes occur in the brain as humans age?
As humans age, the brain shrinks, likely due to lost connections rather than neuron loss. These changes may lead to declining memory function that occurs with age
