Neuroscience Lecture: Brain Organization, Emotion, Sleep, and Somatosensation

Comprehensive vocabulary flashcards covering anatomical directions, brain structures, neuronal signaling, synaptic transmission, autonomic and endocrine regulation, emotion, reward pathways, sleep architecture, and somatosensory mechanisms.

Anterior

Toward the front of the brain

Posterior

Toward the back of the brain

Dorsal

Toward the top of the brain

Ventral

Toward the bottom of the brain

Medial

Toward the midline

Lateral

Away from the midline

Spinal cord

Carries information between the brain and the body

Medulla

Controls vital functions such as breathing and heart rate

Pons

Involved in sleep, arousal, and motor coordination

Cerebellum

Coordinates movement, balance, and motor learning

Midbrain

Involved in vision, hearing, and motor control

Superior Colliculus

Controls visual orienting movements

Inferior Colliculus

Processes auditory information

Thalamus

Where sensory information passes through before going to the cortex

Hypothalamus

Regulates homeostasis, hormones, hunger, thirst, and temperature

Pituitary

Endocrine gland that releases hormones under control of the hypothalamus

Cerebral Cortex

Outer layer responsible for perception, cognition, and voluntary behavior

Occipital Lobe

Vision

Temporal Lobe

Hearing, language, memory

Parietal Lobe

Sensory processing and spatial awareness

Frontal Lobe

Planning, decision making, movement

Central Sulcus

Separates frontal and parietal lobes

Lateral Sulcus

Separates temporal lobe from frontal/parietal lobes

Synapse

Junction where neurons communicate

Terminal

Axon ending that releases neurotransmitters

Dendrite

Receives incoming signals

Presynaptic side of synapse

Transmitting side

Postsynaptic side of synapse

Receiving side

Axon Hillock

Region where potentials begin

Axon

Conducts electrical signals away from the cell body

Myelin Sheath

Insulating layer that speeds conduction

Nodes of Ranvier

Gaps in myelin where action potentials are regenerated

Glia Cell

Non-neuronal support cell

Oligodendrocyte

Produces myelin in the central nervous system

Schwann cell

Produces myelin in the peripheral nervous system

Astrocyte

Supports neurons and regulates the extracellular environment

EPSP

Excitatory postsynaptic potential - increases likelihood of firing an action potential

IPSP

Inhibitory postsynaptic potential - decreases likelihood of firing an action potential

Action Potential

Rapid electrical signal travelling down the axon

Sodium Potassium Pump

Maintains ion gradients using ATP (adenosine triphosphate)

Voltage Gated Na+ Channel

Opens during depolarization, allows Na+ influx

Voltage Gated K+ Channel

Opens later, allows K+ efflux

Voltage threshold for generating an action potential

Membrane potential needed to trigger an action potential (about $-55\,\text{mV}$)

Glutamate

Main excitatory neurotransmitter

GABA

Main inhibitory neurotransmitter

Dopamine

Involved in reward, motivation, and movement

Serotonin

Involved in mood, sleep, and appetite

Acetylcholine

(ACh) involved in muscle activation and attention

Ca++ in presynaptic side

Triggers neurotransmitter release

Synaptic vesicle

Stores neurotransmitter for release

Reuptake mechanism

Recaptures neurotransmitter from the synapse

Ligand-gated Na+ channel

Opens when a neurotransmitter binds, allowing Na+ entry

Second messenger system

Intracellular signaling cascade activated by receptors

Synaptic plasticity

Activity-dependent change in synaptic strength

Hebbian Synapses

“cells that fire together wire together” stronger connections from through coactivation

Autonomic nervous system

Controls involuntary bodily functions

Parasympathetic nervous system

Rest and digest

Parasympathetic ganglia

Relays neurons located near target organs

Neurotransmitter for parasympathetic system (Ach)

Acetylcholine used at both ganglia and target neurons

Sympathetic nervous system

Fight or flight

Sympathetic ganglia

Relays neurons near the spinal cord

Neurotransmitters for sympathetic system

(Ach in ganglia, Noradrenaline in end organ)

Anterior pituitary

Releases hormones under control of hypothalamus

Posterior pituitary

Releases oxytocin and vasopressin made in the hypothalamus

Pituitary hypophyseal portal vein

Carries releasing hormones from the hypothalamus to anterior pituitary

Hypothalamic magnocellular cells

Large neurons that produce oxytocin and vasopressin

Hypothalamic parvocellular cells

Small neurons that regulate the anterior pituitary

Vasopressin

Vole study - loyalty

Oxytocin

Involved in social bonding, childbirth

Thyrotropin releasing hormone

Stimulates release of TSH

Thyrotropin

(TSH) stimulates thyroid gland

Thyroxine

(T4) regulates metabolism

Growth hormone-releasing hormone

Stimulates growth hormone release

Growth Hormone

Promotes growth and metabolism

Dorsolateral hypothalamus

Promotes appetite

Ventromedial hypothalamus

Suppresses appetite

Preoptic nucleus

Involved in temperature regulation and reproductive behaviors

Sham rage

Aggressive responses caused by removal of cortical inhibition

Amygdala

Key structure for emotion, fear studied the most

Kluver-Bucy Syndrome

Syndrome after bilateral amygdala damage causing reduced fear and abnormal behaviors

Fear conditioning

Learning to associate a neutral stimulus with danger

Capgras syndrome

Delusion that familiar people have been replaced by imposters

Toxoplasmosis

Infection by Toxoplasma gondii that can alter behavior

Nucleus accumbens

Central reward structure receiving dopamine input, involved in addiction

Ventral Tegmental Area

(VTA) major dopamine-producing region involved in reward and motivation

Circadian Cycle

Approx $24\,\text{hour}$ rhythm

Pineal gland

(“third eye” in reptiles and amphibians) produces melatonin, light sensitive in some vertebrates

Melatonin

Hormone that promotes sleep and regulates circadian rhythms

Suprachiasmatic nucleus

Brain’s biological clock

Electroencephalogram (EEG)

Measures electrical activity of brain

Awake state

Beta waves, alertness

Quiet resting

Alpha waves

Stage 1 sleep

(Theta waves), light sleep

Stage 2 sleep

(Theta waves + sleep spindles)

Stage 3 sleep

(Delta waves), deep sleep

Stage 4 sleep

(Delta waves), very deep sleep

REM sleep / paradoxical sleep

Rapid eye movements, vivid dreams, brain highly active while muscles are paralyzed

REM rebound

Increased REM sleep after REM deprivation night before

Memory consolidation as a possible function of REM

Process by which memories become more settled

Ascending Reticular Activating System

Starts in medulla, promotes wakefulness and arousal