Ian Waterman
suffered a rare autoimmune reaction to a flu-like virus that attacked the sensory neurons from his neck down. He lost his ability to understand where his body was in space. He could not physically do anything because he was not receiving signals from the neurons in his muscles and joints
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| Term | Definition |
|---|---|
| Ian Waterman | suffered a rare autoimmune reaction to a flu-like virus that attacked the sensory neurons from his neck down. He lost his ability to understand where his body was in space. He could not physically do anything because he was not receiving signals from the neurons in his muscles and joints |
| lesion method | the technique of destroying tissues to determine their functions |
| Herophilus | "Father of anatomy"-- believed that the ventricles (sacs of fluid in the middle of our brains) were the seat of intelligence |
| How many types of Glial cells are there? | Three |
| Glial Cells | Cells that provide support to the nervous system, helping neurons to communicate with one another |
| Microglia | provide immune system support to the nervous system |
| Oligodendrocytes | wraps around the axons of some neurons in the brain and spinal cord- helping to insulate |
| Astrocytes | play a crucial role in moderating how different cells talk to one another |
| Neuron | designed for electrochemical communication--they respond to chemical signals and information from the outside world. |
| Neural Networks | specific patterns which neurons can learn and form connections with one another that persist throughout our lives |
| Dendrites | structures that neurons have that reach out into a fluid filled space called the synapse |
| neurotransmitters | chemical messengers that play a crucial role in transmitting signals between nerve cells (neurons) and other cells in the body |
| excitatory messages or inhibitory messages | neurotransmitters often tell a cell to do what two types of messages? |
| excitatory message | tells the neuron to send its own message to another cell, like a game of "telephone" in which one player tells a message to the next, and so on and so forth |
| inhibitory message | tells the neuron to stop talking to others |
| soma | the body of the neuron-- houses important functions necessary for the cell to sustain itself-- also where neurotransmitters are made |
| axon | on the side of the soma that pinches off from the cell body and elongates into a structure that looks like a long tail and can travel long distances |
| the sciatic nerve | travels from the base of the spinal cord to the big toe |
| nerves | bundles of axons that all travel together to the same place |
| axon hillock | the place where the soma and axon meet, and action potential begins |
| The soma initiates an electrical response called a hillock. This electrical signal, called an action potential, travels down the length of the axon to structures called the axon terminals | What happens when a neuron's dendrites receive enough excitatory messages? |
| terminal buttons | at the tip of the axon-- location where neurotransmitters are released into the synapse |
| postsynaptic receptors | neurotransmitters will bind with these on the membrane of another cell |
| oligodendrocytes | wraps around axons of some neurons in the brain and spinal cord-- have an important function in speeding up the transmission of these action potentials in the central nervous system-- create a substance called myelin which acts like an insulation wrapped around nerves |
| nodes of ranvier | breaks in the myelin-- play an important role in helping the signal to travel down the axon |
| saltatory conduction | when a signal travels down the axon faster |
| Schwann cells | cells which perform a similar function in the peripheral nervous system-- a progression in the speed of a process |
| neural signals (along the axon) are electrical, while neural signals between the cells (across the razor-thin synapse) are chemical | chemical versus electrical signals |
| Sensory neurons | detect information from the environment and translate those signals into the electrochemical language of the nervous system-- 1. where our body is in space, or other senses, 2. they always move information inward or afferently, from the outside world toward the CNS, 3. they don't have dendrites most of the time |
| Motor Neurons | direct muscles to relax and contract, producing movement-- always move information outward or efferently from the CNS toward the muscles so that we can affect the outside world |
| interneurons | acts as messengers between neurons, forwarding the signals generated by sensory neurons to the brain-- 1. found exclusively in the brain and spine, 2. help to relay motor signals from the CNS to motor neurons, or otherwise enable two neurons within the CNS to talk to each other (Such as within the brain), 3. move information both inwardly (afferently) and outwardly (efferently) |
| steps for an excitatory message being received by a cell | 1. neurotransmitter binds to a receptor site on the dendrite, 2. the electrical signal starts at the axon hillock, 3. the message travels down the axon, 4. neurotransmitters are released into the synapse by the terminal buttons |
| the language of the brain is ____ | electrochemical |
| resting potential | the electrical charge that exists between the inside and the outside of the neuron |
| electrostatic pressure | when cells use positively and negatively charged molecules to help send electrical signals in neurons |
| ions | molecules in our bodies that have small electrical charges |
| ions with the same charge do what to each other? | push each other away |
| what charge do neurons have at rest? | a negative charge (-70 mv or -64 mv) |
| polarized | a neuron's resting state |
| where are positively charged ions found | in the extracellular fluid (mostly Na+)-- it actively keeps the negative charge inside of the cell |
| firing rate | how much cells talk |
| depolarized | when a cell becomes more positive |
| the more depolarized a cell becomes, the ____ the probability that the cell will fire an action potential | higher |
| propagation | when the threshold potential is met and additional ion channels along the axon, at the nodes of Ranvier, open as the action potential travels from the hillock to the axon terminals |
| hyperpolarization | a brief period when a neuron cannot create a new action potential because it has pushed too many positive ions out |
| steps of an action potential: | the threshold of excitation is met, the cell depolarizes as positive ions rush in, the cell sends an action potential down the axon, the cell kicks out positively charged ions and repolarizes, the cell kicks out too many positively charged ions and hyperpolarizes, the cell retrieves just a few positively charged ions and returns to resting |
| excitatory neurotransmitters | increases the probability of a neuron having an action potential |
| inhibitory neurotransmitters | decreases the probability that the neuron is activated |
| vesicles | little packages of neurotransmitters inside the terminal button |
| vesicles of neurotransmitters | housed in the presynaptic terminal button |
| presynaptic cell | has an action potential and releases neurotransmitters into the synapse |
| presynaptic | the terminal button of a cell where neurotransmitters are released |
| postsynaptic | the site on a dendrite where neurotransmitters bind to the receptor |
| reuptake | when the presynaptic neuron will reabsorb the neurotransmitter |
| agonists | mimic the action of an endogenous |
| enzymatic deactivation | when the complex molecules that make up neurotransmitters are broken down so their pieces can be reused |
| glutamate | excitatory, learning and movement |
| GABA | inhibitory, learning, anxiety regulation through inhibition of neurons |
| acetylcholine | excitatory, learning, muscle action |
| dopamine | excitatory/inhibitory, learning, reward/pleasure |
| serotonin | excitatory/inhibitory, elevation/depression of mood |
| norepinephrine | excitatory/inhibitory, elevation/depression of mood |
| enkaphalins/endorphins | excitatory/inhibitory, regulation of pain responses |
| threshold of excitation | when the cell receives a signal that enough positive ions are present to create an action potential |
| central nervous system | neuronal network that make up the brain and spine |
| peripheral nervous system | consists of the nerves that connect to the CNS, sending and receiving signals from the rest of the body, |
| enteric nervous system | complex network of neurons that helps the brain communicate with the gastrointestinal tract, often called the "second brain" |
| efferent cells | send motor signals from the central nervous system to the body |
| afferent cells | receive sensory signals from the environment and send them to the spine and brain |
| somatic nervous system | portion of the nervous system that controls the head, torso, and limbs. ex) taking certain paths, speeding up, slowing down, jumping, rolling |
| autonomic nervous system | automatic and involuntary movements. ex) blinking, heart beating, standing up and walking |
| sympathetic nervous system | in charge of preparing for action and expanding energy. ex) pupils dilate, the heart begins to pump blood faster, lungs expand to absorb more energy |
| parasympathetic nervous system | resting and recovering. ex) heart rate and respiration slowing down, storing energy for later |
| the enteric system is the location of a significant portion of the body's _____ | neurotransmitters |
| the gut-brain axis is _____ because the system can send and receive signals from the CNS to the ENS and back again | bidirectional |
| gut-brain axis | pathways that the ENS uses to communicate with the CNS |
| signals generated in the gastrointestinal tract reach the brain via the ____ | axon of the vagus nerve |
| the most protected organs in the body are a part of what system? | the central nervous system |
| cerebrospinal fluid (CSF) | fluid which helps to insulate, protect and maintain buoyancy in the CNS... also responsible for delivering nutrients and removing waste |
| meninges | three layers of connective tissue surrounding the CNS |
| pia mater | layer closest to the brain |
| subarachnoid space | between the pia mater and the next layer, which contains the CSF |
| arachnoid | middle layer of the CNS composed of spindly connective tissue and resembles a spiderweb |
| dura mater | outermost layer of CNS, consisting of tough layers of tissue between the brain and the skull |
| choroid plexus | a kind of tissue found in the ventricles in the center of the brain which produces cerebrospinal fluid constantly |
| ventricles | sacs filled with CSF, which is why the brain is buoyancy neutral |
| anterior or rostral | describes structures in the front of the head |
| posterior or caudal | refers to the structure in the back of the head, but can sometimes also refer to things lower in the nervous system |
| dorsal and superior | structures toward the top of the head |
| ventral and inferior | refer to things lower in the brain |
| medial | moving more toward the middle of the body |
| lateral | moving toward the side, away from the midline of the body |
| hindbrain | most inferior and posterior portion of the brain which regulates signals associated with simple-but essential-life functions like sweating, vomiting, blood pressure regulation, and respiration |
| midbrain | smallest and most central portion of the brainstem-it is superior to the hindbrain and involved in many reflexive behaviors |
| forebrain | most superior and largest portion of the mammalian brain. it includes many structures related to complex behavior, like those related to organizing sensory information (the thalamus), explicit emotional memory (the hippocampus) and the neocortex--a structure that wraps around the top of the mammalian brain and is involved in awareness of thoughts and experiences |
| right brain vs. left brain | we all use both sides of our brain. aspects of human function may require one side more than the other but language is not completely localized to the left size of the brain. |
| corpus callosum | a thick bundle of fibers whose purpose is to connect the two hemispheres and allows them to share information, helps to make sense of crossing messages of sensory information, with the exception of olfaction (smell) |
| gray matter | portion of the CNS made up of dendrites, cell bodies, and unmyelinated axons |
| white matter | the portion of the CNS made up of axons and oligodendrocytes that myelinate the axons |
| hindbrain vs. forebrain behavior | simpler functions closer to the hindbrain and as we move toward the top of the head to the forebrain, functions become more complex |
| medulla | lowest anatomical portion of the brain and the transition point between the brain and the spinal cord. without it we could not breathe, our heart would not beat, and we would not be capable of swallowing |
| pons | regulates arousal (level of excitement/energy) and serves as a bridge for tracts from the upper brain to the lower brain/spinal cord-- also houses clusters of neurons that control facial expressions and eye movements |
| reticular activating system | network of neurons spanning the center of the medulla and pons. it helps to regulate your level of arousal and the focus of your attention |
| glia (nuclei, ganglia) | network of neurons in the limbic system, basal ganglia, and cerebellum designed to modify thoughts and behaviors |
| limbic system | large network of structures that helps to regulate hormones, emotions, and some kinds of memory |
| amygdala | increases electrical activity in its neurons when we are emotionally aroused. involved in aggression, fear, appetite, and responsible for the increased secretion of norepinephrine (adrenaline) in the body during our flight or fight response. plays a key role in the forming of memories of strong emotional event and acquisition of trauma responses |
| Hippocampus | shaped like a seahorse in the middle of the brain and contains neurons that are activated when we are forming personal memories and even the imagining new possibilities ○ Not our entire memory system, but repeatedly activating its neurons is necessary for the cataloging of new experiences ○ Relationship of the hippocampus and the amygdala to the memory of new and emotionally important events and objects is crucial to our survival |
| Basal ganglia | interconnected groups of neurons that modulate movement commands in the brain before they reach the spinal cord ○ They wrap closely around the side of the thalamus ○ Involved in helping us learn to make complex movements (and skills more generally) more automatic |
| substantia nigra | part of the basil ganglia that is a neuronal circuit where a large number of terminal buttons of these neurons secrete dopamine |
| Cerebellum | rhythm and timing machine. The neuronal circuits in the layers of the cerebellum are strategically connected with other parts of the brain to modify what they do, especially for movement, but also in cognitive tasks ○ Circuits in the cerebellum are set up to simultaneously receive and organize input from multiple central nervous system networks ○ Also coordinates thought and problem-solving as well as control of emotional responses by connecting with association areas of the neocortex and the hypothalamus |
| Thalamus | some kinds of memory, auditory information, and language processing |
| neocortex | the location of what we typically consider high-level processing |
| Humans differ greatly from other animals in two ways | 1. The number of connections in the neocortex 2. the area dedicated to the frontal lobes, which govern personality, context, and decision-making |
| Parietal Lobe | Process information about the self and the relationship between the self and the space around "you." |
| somatosensory cortex | in the parietal lobe-- the portion of the brain that does the heaviest lifting when it comes to integrating the skin senses: touch, pain, and temperature |
| upper part of the parietal lobe | involved in working memory, spatial orientation, and attention, especially regarding the area near the hands |
| The lower part (the inferior parietal lobule) | involved in tasks as varied as language and mathematics: damage to the area appears to cause all sorts of problems with physically and mentally manipulating things, and may lead to deficits in reading, writing, and arithmetic |
| Wernicke's area | left temporal lobe-- important area for the processing of language |
| Frontal Lobe | Decision-making and movement |
| prefrontal cortex | receives input from all parts of the cerebral cortex--helps us decide when, why, and how we do things-- also contributes to our personality and where we integrate a number of memories and emotions |
| Phineas Gage | He was impaled with a metal rod through his frontal lobe and his personality changed drastically. Since then, scientific research has provided significant and convincing evidence that the prefrontal cortex is involved in decision-making, morality, and facets of what we call personality |
| Occipital Lobe | - Processing and interpreting visual information from the sensory neurons in the eyes |
| Dorsolateral prefrontal cortex | controls working memory |
| Primary motor cortex | sends efferent commands for voluntary movements |
| Somatosensory cortex | receives afferent signals about the state of the body |
| Ventromedial prefrontal cortex | regulates fear-based behavior |
| what causes the wrinkles in the brain | the gyri (small bumps), sulci (small grooves), and fissures (large spaces between lobes)-- allows us to fit more into a smaller space |
| association cortex | next to the primary lobes and contributes in further processing information, helping to integrate it with other sensory information |
| how do scientists study the nervous system | • Scientists change how they speak to each other through manipulating chemical messages, the electrical activity, or measuring changes in neural behavior |
| Lesions, Case Studies, Psychosurgery | - studying people who naturally experience brain damage due to accidents, strokes, illness, or tumors, and observational in nature |
| Magnetic Resonance Imaging (MRI) | - Uses different frequencies to understand different tissue types in the brain - You can look at different sizes of different parts of the brain and look at anything that looks off |
| Positron Emission Tomography (PET scans) | - Looks at brain function, radioactive tracer is injected into you and it sticks to certain things so when you are put into a PET scanner, you can see what parts of the brain are having blood or glucose delivered when in a certain cognitive state or doing a certain cognitive task - Shows what is active overall during a particular moment/task |
| fMRI: The Brain in Action | - Similar to PET but you often don’t need an injection - Measures blood flow, the deoxygenation of blood flow. - When there is brain activity in certain parts of the brain there is an increase of blood which can be measured in numbers - Can help understand functionality--> what parts of the brain are used correlationally |
| Single-Unit Recording | • Microscopic electrode is placed close to (sometimes inside of) a single neuron to measure its individual firing rate • Considered invasive because it is an electrode directly inserted into the brain Typically used experimentally with non-human animals |
| Electroencephalography (EEG) | - Wires that connect on top of our head, measuring the electrical activities that travel to the surface of our brains - Cleverly analyze the waves that show up on a screen to see what type of cognitive state people in/cognitive processes are being used |
| Transcranial Magnetic Stimulation (TMS): The "Virtual Lesion" Tool | Strong magnets that can alter neurofunction. a noninvasive, outpatient procedure that uses magnetic fields to stimulate nerve cells in the brain. TMS Current Flow: changes the flow of the brain activity/networks that are being impacted |
| Pharmacological Perturbations | • Administering drugs allows for a casual inference |
| Quasi-Brain Perturbation Approaches | Technique to measure natural manipulations or changes of brain activity in different people Lesions, development, aging, disease |
| Brain Perturbation Approach | Technique to manipulate or change brain activity in different people or under different mental states. Growing in popularity, but not emphasize. Can infer causality (to some extent) which is a pro |
| Functional Near-Infrared Spectroscopy (FNIRS) | - Method: Light - Purpose: Portably detect small to large functional changes - Pro: Can be used on people with mental implants and portable - Cons: Spatial resolution not as good as fMRI |
| phrenology | studying bumps on the head and relating these to abilities and personalities |
| modern view | complex behavior is the result of a conversation between many brain parts, not one-to-one mapping |