Ch 12: MEMORY (Brain regions, neural network and hormones)

Cerebral cortex:

Lashley first searched here, but his results suggested that many learning tasks are distributed rather than stored in one tiny cortical location.

Cerebellum:

The major site for the eyelid-conditioning engram in Thompson’s work and important for precise timing in conditioned responses.

Lateral interpositus nucleus (LIP):

The critical cerebellar nucleus where learning occurred in the rabbit eyelid-conditioning experiments.

Red nucleus:

Needed to express the conditioned eyelid response, but not necessary for the learning itself.

Hippocampus:

Important in memory stabilization and especially relevant to emotionally enhanced and developmental memory questions

Amygdala:

Helps strengthen memories for emotionally important experiences.

Locus coeruleus:

Arousal-related brainstem site that boosts norepinephrine release during emotional events and helps strengthen memory

Occipital cortex:

Damage here can selectively impair the formation of new visual memories

Prefrontal cortex:

Important for working memory and the active control of information during a delay

Parietal cortex:

Partners with prefrontal cortex in working memory and attention during delay tasks.

Thalamus:

Participates in cortex-thalamus reverberating loops that support working memory.

CS–UCS association network:

Pavlov imagined a connection that lets activity spread from the CS center to the UCS center.

Reverberating circuit

Hebb’s proposed loop in which neurons stimulate each other in a sequence, with a final neuron looping back to re-excite the initial neuron.

This positive feedback loop creates sustained, repetitive activity from a single stimulus.

Reverberating circuit use

playing a key role in short-term memory, breathing, and heart rate regulation

Cortex–thalamus

The working-memory loop that keeps information online during a delay and codes only the details needed for the task

Emotion-memory network:

emotional arousal recruits the locus coeruleus, cortex, hippocampus, and amygdala to strengthen memory formation

Synaptic tag-and-capture pathway:

explaining how weak, transient synaptic memories are stabilized into long-term memories. It involves setting a local tag at activated synapses and capturing "plasticity-related proteins" (PRPs) synthesized in the cell body, allowing specific synapses to strengthen

Norepinephrine:

rises throughout the cortex during emotional arousal and contributes to stronger encoding

Dopamine:

increases in the hippocampus during emotional experiences and helps stabilize memory formation.

Epinephrine:

part of the body’s stress/arousal response and contributes to emotional strengthening of memory

Cortisol:

stress hormone that also helps activate memory-relevant circuits during emotional events.

Microglia-related inflammatory signaling:

not a hormone, but important in brain fog and Alzheimer’s-related damage.