Neuroscience (Module 2 Ch 3) Flashcards
Memorize by October 10th
Polygenic vs Monogenic
Characteristic is determined by the interaction of several genes vs determined by a single gene
Behavioral Genetics
The study of how heredity affects behavior
Is often very complex since most characteristics are polygenic as well as influenced by environmental factors
Heritability
The extent to which a characteristic is influenced by genetics
What extent is a trait caused by nature? What extent is it caused by nurture?
Epigenetics
The study of changes in the way genes are expressed without changing the sequence itself
Genes can be activated or deactivated based off of environmental conditions
Soft Inheritance
The process by which genes are inherited via epigenetics
Neurons
Cells in the nervous system that communicate with each other
Everything that you do or think starts with neurons
Dendrites
Reach out into the nervous system, collect information, and bring it to the neuron
Cell Body
AKA the Soma
Decides whether or not to send that information to the next neuron
Where the nucleus is located
Axon
Works as a hallway
Gets information from the soma to the end of the neuron
Myelin Sheath
What the axon is wrapped in
Helps speed up transmission
Terminal Buttons
The end of the neuron
Releases information onto the next neuron
Synapse
The space between neurons
Glial Cells
Help support neurons
What are the different functions of glial cells?
Creating a skeletal system (helping with structure), nourishing the neurons, creating myelin, repairing damage, removing waste, creating the blood-brain barrier
The blood brain barrier
Separates the blood from the brain to prevent toxins from reaching the brain
What are the different types of neurons?
Sensory, Motor, Mirror, Inter
What do sensory neurons do?
Take information from the senses (your eyes, skin, ears, etc.) and transmits it to the brain for processing
What do motor neurons do?
Takes directions from the brain to the muscles to help us move
Afferent vs Efferent
Takes information to the brain vs takes information from the brain
What do mirror neurons do?
Allow us to mirror other people both physically and emotionally
Essential to empathy
What are interneurons?
Neurons that are connected to other neurons
Electrical vs Chemical Information Transmission
Occurs within a neuron vs occurs between neurons
Action Potential
Changes in electrical charge along the axon of a neuron from -70mV to +40mV
Caused by the movement of charged potassium and sodium ions into and out of the axon
Resting Potential
The difference between the inside and outside of the axon when the neuron is at rest (-70mV)
Propagation
The process in which an impulse moves down the axon
Node of Ranvier
The gaps in the myelin sheath that the action potential jumps across
Absolute vs Relative Refractory Period
No matter what, the neuron will not fire again vs the neuron can fire again, but only if triggered by a stronger stimulus
Neurotransmittors
How neurons send information to each other
Synaptic Vesicles
Sacs in the terminal buttons that contain neurotransmitters
Agonists vs Antagonists (medication)
makes a neurotransmitter more effective vs makes a neurotransmitter less effective
Dopamine
Related to reward, pleasure, and voluntary movement
Too much = Schizophrenia
Too little = Parkinson’s
Serotonin
Controls negative emotionality and regulates sleep and focus
Too little = Depression or Anxiety
Epinephrine
Gives you an energized mental state (aka adrenaline)
Norepinephrine
Gives you an energized mental and physical state
Too little = Depression
Too much = PTSD
Endorphins
The body’s natural pain killer, also associated with a positive emotional state
GABA
Primary inhibitory neurotransmitter, meaning it tells the cell body to stop sending information
One of the most abundant neurotransmitters
Dysfunction = Epilepsy
Glutamate
Primary excitatory neurotransmitter, meaning it tells the cell body to continue sending information
Acetylcholine
Important to learning, memory, attention, and sleeping
Has a strong relationship with motor neurons
Dysfunction = Memory Disorders such as Dementia and Alzheimer’s
Law of Forward Condition
Information transmission always goes from the dendrites through the axon to the terminal buttons (never the other way around)
All or None Principle
If the soma decides to send the information along, it will travel the whole length of the axon (it’ll never stop halfway down)
Excitatory vs Inhibitory
The soma decides between whether or not is should send the information (excitatory) or not (inhibitory)
Neuropeptides
Small strings of amino acids that aren’t formally considered neurotransmitters
Enzymatic Degradation
Enzymes within the nervous system basically eat the leftover neurotransmitters in the synapse
Reuptake
Leftover neurotransmitters in the synapse are taken back in by the terminal buttons that released them
Synaptic Pruning
The dying off of certain synapses that are no longer useful, helping make the brain more efficient
Brain
the center of the nervous system
Intelligence does not correlate with brain size, it correlates with…?
Surface area
How do you increase the surface area of the brain without increasing size?
Wrinkles
New builds on old
Evolutionarily and developmentally, the newer parts of the brain are towards the top while the older parts are towards the bottom
Contralateral Control
The right side of the brain controls the left side of the body and vice versa
Association Area
What parts of the brain are responsible for which components of thinking
What are the three different brain divisions?
Hindbrain, Midbrain, and Forebrain
Hindbrain
The oldest
Conducts information through the spinal cord to the rest of the brain
Primary goal is to keep you alive through vital bodily functions
Midbrain
The smallest division of the brain, located in the center
Controls orientation and moving us through space
Takes in a lot of visual information and processes bodily movement
Important source of dopamine
Forebrain
The top part of the brain
Highest level in terms of both function and location
Controls cognitive, sensory, and motor function
Medulla
Located in the hindbrain
Controls heart rate, circulation, respiration, and reflexes
Reticular Formation
Located in the hindbrain
Controls sleep, mood, and arousal/focus (crucial to waking up and falling alseep)
Important for serotonin and norepinephrine
Pons
Located in the hindbrain
Manages sleep, focus, and facial expressions (including understanding others and making our own)
Relays information to the cerebellum
Cerebellum
Located in the hindbrain
Has the most neural connections
Controls balance, fine motor movement, gracefulness, and coordination
Tectum
Located in the midbrain
Receives sensory information and connects it to movement
Essentially helps build a picture of the environment
Tegmentum
Located in the midbrain in front of the Tectum
Focuses on movement and focus
Essentially helps you navigate the environment that the tectum creates a picture of
Cerebral Cortex
The outer wrinkly layer of the forebrain, divided into four lobes per side (8 total)
Corpus Callosum
The band of fibers that connects the two halves of the brain
Without it, the right side wouldn’t be able to communicate with the left
Subcortical Structures
Located in the forebrain beneath the cerebral cortex, including the thalamus, pituitary gland, and limbic system
Thalamus
Located in the forebrain
One of the subcortical structures
The way station for all sensory information except smell
Pituitary Gland
Located in the forebrain
One of the subcortical structures
Controls the release of hormones
Limbic System
Located in the forebrain
Part of the subcortical structures
Represents your emotional brain
Hypothalamus
Part of the Limbic system
Controls the four F’s: feeding, fleeing, fighting, and f*cking
Also controls the Pituitary Gland
Amygdala
Part of the Limbic system
Critical for emotional memory, especially negative ones such as anger, fear, and disgust
Hippocampus
Part of the Limbic system
Critical for memory
Cingulate Gyrus
Part of the Limbic system
Band of fibers that focuses on directing attention
Decreased function of this area is associated with Schizophrenia
Basal Ganglia
Part of the Limbic system
Focuses on motor control
High levels of dopamine present
Decreased function in this area is associated with Parkinson’s
What are the four lobes of the cerebral cortex?
Frontal, Parietal, Occipital, and Temporal
Frontal Lobe
Controls high order processing such as decision making, reasoning, and creativity
Prefrontal Cortex
The front most part of the frontal cortex
Disproportionately large in humans (28% of frontal lobe)
Considered the executive decision-maker (determines whether we should engage in something or not)
Doesn’t fully develop until early to mid 20’s
Motor Cortex
Located in the frontal lobe
Concerned with general movement
Most of it is dedicated to the movement of the mouth, tongue, and hands
Homunculus
An artistic rendering of what humans would look like if they were proportioned like either their motor cortex or their somatosensory cortex (basically has really big hands and mouth)
Phineas Gage
Had a piece of railroad sent under his cheek and through his frontal lobe, which drastically changed his personality
Described as being more short-tempered and having a harder time with tasks after the incident
Parietal Lobe
Located directly above the midbrain
Focuses on orientation, visual integration, and touch
Somatosensory Cortex
Located right behind the motor cortex (but considered part of the parietal lobe)
Focuses on touch sensations (relating to the skin)
Visual Integration
Relating visual information (which comes from the occipital lobe) to movement
Occipital Lobe
Builds visual information
Starts by creating simple features like color and shape, then processes them into more complex images
Temporal Lobe
Focuses on hearing, language, and recognition
Significant lateralization occurs here
Lateralization
The idea that certain parts of the brain differ depending on left or right hemisphere
What does the right side of the temporal lobe focus on?
Non-language sounds
What does the left side of the temporal lobe focus on?
Language
Broca’s Area
Located on the left side of the temporal lobe
Allows for speech production
Wernicke’s Area
Located on the left side of the temporal lobe
Allows for speech comprehension
Aphasia
Damage to the brain that affects the ability to communicate (speak or comprehend language)
Broca’s Aphasia
Being unable to produce the words that you want to
There is an understanding by the person that the sounds coming out of their mouth aren’t really words and don’t make sense
Wernicke’s Aphasia
Words still come out, but there’s no meaning behind them
Cannot understand what you’re saying to them
Auditory Cortex
Located in the temporal lobe
Processes sound
Insula
A small structure located between the temporal and parietal lobes that focuses on perception of sensations, emotional states, empathy, and addictive behavior
The Nervous System
Controls all the actions and automatic processes of the body
Everything we experience and do is the result of activity in nerve cells
Central Nervous System (CNS)
The brain and spinal cord
Spinal Cord
Can respond to certain inputs without directions from the brain
Gate Control Theory
The spinal cord can block pain signals from getting to the brain, so that the brain can process information without getting distracted
Cerebrospinal Fluid
Fluid that protects or cushions the CNS from danger
Also nourishes the CNS using glucose
Peripheral Nervous System (PNS)
All other nerve cells outside the CNS
Include the Somatic Nervous System and the Autonomic Nervous System
Somatic Nervous System
Transmits info back and forth between the CNS and the skeletal muscles
Voluntary
Autonomic Nervous System
Serves the involuntary bodily systems (aka those involving organs and glands)
Includes two branches: sympathetic and parasympathetic
Sympathetic Nervous System
Branch of the ANS that activates bodily systems in times of emergency
I.E. responsible for flight or fright
Parasympathetic Nervous System
Branch of the ANS that relaxes the body, returning it to a state of rest or low activity (aka rest and digest)
Mediates the effects of the Sympathetic Nervous System
Enteric Nervous System
Nerve cells embedded in the gastrointestinal system that are sometimes referred to as “the second brain”
Controls hunger signals and is responsible for our “gut feelings”
95% of serotonin in the body is found here
Neuroplasticity
The brain’s ability to adopt new functions, reorganize itself, and make new neural connections as needed across life and experience
Varies with age and region of the brain (some are more plastic than others)
Neurogenesis
The development of new neurons
Arborization
The growth/formation of new dendrites
Synaptogenesis
The formation of new synapses or connections with other neurons
What brain imaging techniques show us structure?
MRI, DTI, NIRS
Also mesoSPIMS
What brain imaging techniques show us activity?
EEG (+ ERP), fMRI, PET, TMS
mesoSPIMS
Uses light-sheet microscopes to view individual neurons
Does not show activity
MRI
Uses magnets to produce still images of the brain’s structure, but does not tell us anything about activity
DTI
Type of MRI that focuses on where myelin is
NIRS
uses light pulses to produce images of the brain rather than magnets
fMRI
Uses magnets to track the metals in our blood
Allows us to see where activity is occurring, but not when
Extremely expensive
EEG
Imaging technique that involves placing electrodes on the skull to measure activity
Good at telling us exactly when activity occurs, but not where
ERP
Specific pieces of data from a single electrode used in an EEG
PET
Tracks where glucose is going to tell us which parts are the most active (and thus need the most fuel)
TMS
Uses a coil to send magnetic pulses through the brain, disrupting normal processing
One of the only non-invasive ways to determine causality
Endocrine System
The system of glands that regulates the secretion of hormones in the body
Hormones
Chemicals that travel in the blood stream, carrying messages to tissues and organs
What glands are part of the endocrine system?
Pituitary (the master gland, controls release of hormones), thyroid (controls metabolism), pancreas (controls blood sugar), ovaries/testes (control sex hormones), adrenal (responds to stress and emotions by regulating heart rate, blood pressures, and blood sugar)
Catecholamines
Chemicals produced by the adrenal glands that can act as hormones or neurotransmitters
Control ANS activation, including fight or flight
Includes dopamine and norepinephrine
Cortisol
A stress hormone released by the adrenal glands that regulates metabolic functions
