Week 8 ELM 16: Learning and Memory I

Vocabulary flashcards about learning and memory processes, mechanisms, and disorders.

Learning

The acquisition of new knowledge or skills; an adaptive process.

Memory

The retention of learned information, linked to storage and retrieval.

Non-Declarative Memory (Implicit)

Type of memory including procedural skills/habits, associative learning, and conditioned responses.

Declarative Memory (Explicit)

Type of memory including facts and events.

Hippocampus

Brain region primarily associated with explicit memory and spatial navigation.

Cerebellum and Basal Ganglia

Brain regions primarily associated with procedural memory.

Amygdala

Brain region primarily associated with emotional responses.

Place Cells

Hippocampal neurons that fire at a high rate when an animal is in a specific location (place field).

Cognitive Map

An internal neural representation of the landscape in which an animal travels.

Short-Term Memory

Memory that lasts for seconds to hours, has limited capacity, and is sensitive to disruption. Repetition promotes retention. Limited capacity. “Labile” (sensitive to disruption). Does not require new RNA or protein synthesis

Long-Term Memory

Memory that lasts for days to years, has unlimited capacity, and is consolidated (insensitive to disruption). Unlimited capacity. Consolidated (insensitive to disruption). Does require new RNA or protein synthesis

Consolidation

The process by which short-term memories become long-term memories.

Encoding

The first stage of memory processing where the brain receives information.

Storage

The second stage of memory processing where the brain retains information.

Retrieval

The third stage of memory processing where the brain retrieves and utilizes information.

Hebbian Plasticity

The concept that neurons that fire together, wire together; synaptic connections strengthen with simultaneous activity. NEURONS THAT FIRE TOGETHER WIRE TOGETHER

Long-Term Potentiation (LTP)

A persistent strengthening of synapses following high-frequency stimulation, leading to increased signal transmission between neurons. Strong depolarization will lead to high levels of Ca 2+

AMPA Receptor

Glutamate receptor that allows Na+ influx when glutamate binds and the receptor opens.

NMDA Receptor

Glutamate receptor that requires glutamate, glycine, and depolarization to open, allowing Na+ and Ca2+ influx.

Long-Term Depression (LTD)

A long-lasting decrease in the efficiency of synaptic transmission. Weak depolarization will lead to little Ca 2+ influx

Amnesia

Loss of memories, often resulting from trauma; can be transient or permanent.

Anterograde Amnesia

Difficulty learning new information after the onset of amnesia.

Retrograde Amnesia

Difficulty remembering past information before the onset of amnesia.

Dementia

A group of symptoms affecting memory, thinking, and social abilities; Alzheimer’s disease is the most common cause.

Alzheimer's Disease (AD)

A form of dementia characterized by neurofibrillary tangles and beta-amyloid plaques, leading to memory loss and cognitive decline.

Vascular Dementia (VD)

The second most common cause of dementia, resulting from stroke or conditions damaging blood vessels in the brain.

Increased grey matter in hippocampus is correlated to

More spatial knowledge. London taxi drivers have more grey matter in their hippocampus than bus drivers.

Dendrites contain a large number of ____ that form contacts (synapses) with other neurons

Dendritic spines

LTP mechanisms

AMPA and NMDA receptors involved. First presynpatic changes occur, increased NT vesicles and NT release. Then, post synaptic changes: increased dendritic area and spines (increased sensitivity) and increase AMPA receptors

Postsynaptic mechanisms

Diverse signaling pathways involved. PKA plays an important role. Different pathways converge on common targets (e.g. ERK). Requires protein synthesis

What causes long term potential of active synapses

Synaptic transmission occurring at the same time as strong depolarization of the post synaptic neuron

What causes long term depression of the active synapses

Synaptic transmission occurring at the same time as a weak or modest depolarization

Physiological functions of LTD

Hippocampus- dependent learning and memory (working and episodic memory, novelty detection). Fear conditioning in amygdala. Recognition memory in perirhinal cortex. Cerebellar learning

Pathological states LTD is involved in

Psychiatric disorders, drug addiction, mental retardation (fragile X syndrome), neurodegenerative disease (Alzheimer’s)

Patient HM

Most studied individual in the history of neuroscience. He had a bilateral medial temporal lobe resection that lead to anterograde amnesia. he could not remember anything after the operation but his old memories were in tact. His case allowed scientists to discriminate before long / short term memory and declarative / non declarative memory