Neuroscience Lecture Series – Learning, Memory, Motivation & Motor Systems

100 question-and-answer flashcards summarizing major topics from the neurobiology lecture series, including memory, learning mechanisms, motivation, depression, attention, motor systems, and related model organisms.

What is the neuroscientific definition of learning?

The acquisition of new skills, information, or knowledge.

What is memory in neuroscience?

The ability to store learned information and recall it later.

What does Miller’s ‘magical number’ 7 ± 2 describe?

The average number of items (chunks) that can be held in human short-term/working memory.

What is priming?

An unconscious memory effect where prior exposure to a stimulus speeds or eases later responses to related stimuli.

Define prosopagnosia.

A neurological condition characterized by the inability to recognize faces.

What is habit formation?

The process by which repeated behaviors become automatic or routine, triggered by specific cues.

Which brief memory store holds unfiltered sensory information for fractions of a second?

The sensory register (iconic for vision, echoic for audition). It retains sensory information just long enough for initial processing before it's either discarded or sent to short-term memory.

How long does unattended information typically last in short-term memory?

About 20 seconds unless rehearsed or encoded.

What technique can expand working-memory capacity?

Chunking—grouping items into meaningful units.

Which two major divisions make up long-term memory?

Implicit (non-declarative) and declarative (explicit) memory.

Give two examples of implicit memory types.

Procedural (motor skills) and classical conditioning (associative memory).

What are episodic memories?

Declarative memories for personal events with contextual details of time and place.

What are semantic memories?

Declarative memories for facts and general world knowledge.

Differentiate retrograde from anterograde amnesia.

Retrograde: loss of memories before trauma; Anterograde: inability to form new memories after trauma.

State Hebb’s rule in one sentence.

‘Neurons that fire together, wire together.’

According to Hebb, why doesn’t partial damage erase an entire memory?

Because the memory (engram) is distributed across many synapses in a neuronal assembly.

What are ‘grandmother neurons’?

Hypothetical neurons that respond only to a very specific complex stimulus, such as the concept of one’s grandmother.

List three key roles of the hippocampus in declarative memory.

Encoding of new memories, consolidation into long-term storage, and retrieval of recent memories.

What are place cells?

Hippocampal neurons that fire when an animal is in or thinking of a specific location.

Name the brain circuit linking hippocampus, mammillary bodies, anterior thalamus and cingulate cortex.

The Papez circuit.

Which brain structure is essential for fear conditioning?

The amygdala.

What learning function is the striatum best known for?

Procedural learning and habit formation via reinforcement.

Define habituation.

A decrease in response to a repeated, harmless stimulus.

Define sensitization.

An increased response to a stimulus following a strong or noxious stimulus.

Which sea slug is a classic model for studying habituation and sensitization?

Aplysia.

In Aplysia sensitization, which neurotransmitter released by an interneuron triggers cAMP production?

Serotonin.

What is the conditioned stimulus (CS) in Pavlov’s original experiment?

The bell tone predicting food.

Which Drosophila brain region is critical for olfactory associative memory?

The mushroom bodies (Kenyon cells).

Which enzyme in Kenyon cells detects coincidence of odor (Ca²⁺ influx) and shock (dopamine)?

A dually regulated adenylyl cyclase (encoded by rutabaga).

What cellular change characterizes hippocampal long-term potentiation (LTP)?

A long-lasting increase in synaptic strength following high-frequency stimulation.

Which receptor acts as a coincidence detector during LTP?

The NMDA receptor (requires glutamate binding and postsynaptic depolarization).

Name two postsynaptic consequences of Ca²⁺ influx during LTP.

Insertion of additional AMPA receptors and gene expression changes for long-term maintenance.

Which gaseous messenger can strengthen presynaptic release during LTP?

Nitric oxide (NO).

What type of plasticity weakens parallel-fiber inputs onto Purkinje cells in the cerebellum?

Long-term depression (LTD).

State the three conditions required for cerebellar LTD.

Glutamate at AMPA-R, glutamate at mGluR1, and climbing-fiber-induced Ca²⁺ influx.

What does the BCM theory propose?

Whether a synapse undergoes LTP or LTD depends on the level of postsynaptic activity relative to a shifting threshold.

Which transcription factor pair regulates gene expression for long-term memory via cAMP/PKA?

CREB-1 (activator) and CREB-2 (repressor).

What genetic tool allows targeted gene expression in Drosophila neurons?

The GAL4-UAS system.

How does the Split-GAL4 system improve specificity?

GAL4’s DNA-binding and activation domains are expressed under separate promoters and reassemble only in cells expressing both.

What is path integration in Drosophila’s ellipsoid body used for?

Idiothetic (self-motion) orientation and operant learning of heat avoidance.

Which gaseous transmitter provides ultra-short visual working memory in the ellipsoid body?

Nitric oxide (NO).

Where is life-long ‘body-size memory’ stored in the fly brain?

The protocerebral bridge.

Name four temporally distinct memory phases identified in Drosophila.

Short-term (STM), middle-term (MTM/ITM), anesthesia-resistant (ARM), and long-term memory (LTM).

Define motivated behavior.

Volitional actions performed to satisfy an internal need under environmental opportunity.

Which hypothalamic peptide hormone signals sufficient fat stores and suppresses feeding?

Leptin.

Name two orexigenic peptides released when leptin is low.

Neuropeptide Y (NPY) and Agouti-related peptide (AgRP).

What gut hormone is released by an empty stomach to stimulate hunger?

Ghrelin.

Describe the monoamine hypothesis of depression.

Depression results from deficient activity of monoamine neurotransmitters (serotonin, norepinephrine, dopamine).

What axis becomes overactive in depression, leading to excess cortisol?

The hypothalamus–pituitary–adrenal (HPA) axis.

What is the diathesis-stress hypothesis?

Mental disorders arise when genetic/biological vulnerability interacts with significant life stress.

How can ketamine exert rapid antidepressant effects?

By blocking presynaptic NMDA receptors, boosting glutamate release, activating AMPA receptors, and triggering BDNF-mTOR–mediated synaptogenesis.

What is learned helplessness?

A state where repeated uncontrollable stress leads to passive behavior and depression-like symptoms.

Which three neurotransmitters modulate depression-like states in flies?

Serotonin, dopamine, and GABA.

What is selective attention?

The cognitive process of focusing on specific stimuli while ignoring others.

Which brain imaging method measures blood oxygenation differences (BOLD signals)?

Functional MRI (fMRI).

What visual phenomenon reveals competition for conscious perception between eyes?

Binocular rivalry.

Which right-hemisphere parietal lesion can cause hemispatial neglect?

Damage to the posterior parietal cortex (pPC).

What are mirror neurons?

Neurons that fire both when an individual performs an action and when they observe the same action performed by others.

Which human brain areas contain mirror-neuron-like activity?

Inferior frontal gyrus, ventral premotor cortex, and inferior parietal lobule.

How is autism linked to the mirror-neuron hypothesis?

Reduced mirror-neuron system activity may contribute to social and empathy deficits, though the theory is debated.

What non-invasive technique uses magnetic pulses to modulate cortical activity?

Transcranial magnetic stimulation (TMS).

What cortical map represents body parts in order across the motor cortex?

The somatotopic motor homunculus on the pre-central gyrus.

Which tract conveys voluntary motor commands from cortex to spinal cord in primates?

The corticospinal (pyramidal) tract.

Define a motor unit.

One α-motor neuron and all the skeletal muscle fibers it innervates.

What is Henneman’s size principle?

Motor units are recruited from smallest (fatigue-resistant) to largest (powerful) as force demand increases.

Which spinal sensory receptors detect muscle length and its rate of change?

Muscle spindles (via Ia afferents).

What is the inverse myotatic (Golgi tendon) reflex?

Ib afferents from tendon organs inhibit the same muscle when tension is excessive, protecting against damage.

What are central pattern generators (CPGs)?

Spinal or brainstem circuits that produce rhythmic motor patterns (e.g., walking) without sensory input.

Which midbrain region can initiate locomotion when electrically stimulated?

The mesencephalic locomotor region (MLR).

What giant brainstem neuron triggers the fish ‘C-start’ escape reflex?

The Mauthner cell.

Name the three main cortical motor areas anterior to primary motor cortex.

Premotor cortex, supplementary motor area (SMA), and frontal eye field.

What effect does decortication have on movement?

Basic posture and reflexes remain, but voluntary fine control, especially finger movements, is lost.

Define cortical plasticity.

The capacity of cortical maps and synapses to reorganize with learning, experience, or injury.

What is action-activated focal dystonia?

Task-specific involuntary muscle contractions (e.g., musician’s cramp) due to maladaptive cortical plasticity.

Which three deep cerebellar nuclei are collectively called the ‘interposed nuclei’?

Globose and emboliform nuclei (sometimes grouped together).

What are the two major excitatory inputs to Purkinje cells?

Parallel fibers (from granule cells) and climbing fibers (from the inferior olive).

During cerebellar LTD, which kinase phosphorylates AMPA receptors for internalization?

Protein kinase C (PKC).

State one non-motor cognitive role of the cerebellum.

Contribution to language, working memory, or executive function via the cerebrocerebellum.

Differentiate the direct and indirect basal ganglia pathways.

Direct pathway facilitates movement; indirect pathway inhibits movement.

Which neurotransmitter from substantia nigra modulates both pathways?

Dopamine—excites direct (D1) and inhibits indirect (D2) pathway neurons.

List two cardinal motor symptoms of Parkinson’s disease.

Bradykinesia and resting tremor (others: rigidity, postural instability).

How does L-DOPA help Parkinson’s patients?

It is a dopamine precursor that crosses the blood–brain barrier and is converted to dopamine in surviving neurons.

What genetic mutation causes Huntington’s disease?

Expanded CAG trinucleotide repeats in the HTT gene producing mutant huntingtin protein.

What involuntary movement characterizes Huntington’s disease?

Chorea—dance-like, writhing movements.

Name two common treatments for major depression besides SSRIs.

Lithium (esp. bipolar disorder) and electroconvulsive therapy (ECT); others include ketamine or psychotherapy.

What is a genome-wide association study (GWAS)?

A research approach that scans the genome for SNPs associated with a trait or disease across many individuals.

How does proline in the gut–brain axis potentially influence mood?

High dietary/ microbial proline may reduce GABA synthesis, disrupt rich-club brain networks, and promote depression-like states.

What is the main function of the pulvinar nucleus in attention?

Filtering visual input and enhancing relevant signals during selective attention.

Which neuron in the Drosophila mushroom body provides wide-field GABAergic inhibition for sparse coding?

The Anterior Paired Lateral (APL) neuron.

What EEG wave pattern is typical of deep non-REM sleep?

Delta waves (< 4 Hz).

Describe REM sleep in two features.

Rapid eye movements with desynchronized (beta-like) EEG and skeletal muscle atonia.

What spinal interneuron provides recurrent inhibition of α-motor neurons?

The Renshaw cell.

Which mechanistic model explains glucose transporter conformational change?

The rocker-switch model.

In PET imaging, what tracer is commonly used to assess brain glucose metabolism?

18F-fluorodeoxyglucose (18F-FDG).

What phenomenon shows that perception alternates between two possible interpretations of the same stimulus?

Ambiguous figures (e.g., Necker cube or Rubin’s vase).

What is selective hearing (cocktail-party effect)?

The ability to attend to one sound source while filtering out background noise.

Which neurodevelopmental disorder involves inattention, hyperactivity, and dopaminergic dysfunction?

Attention-deficit/hyperactivity disorder (ADHD).

Define theory of mind.

The capacity to attribute mental states to oneself and others, understanding that they can differ from one’s own.

Which glial cell type guides Purkinje cell development and supports cerebellar synapses?

Bergmann glia.