What is neuroscience?
The study of the nervous system.
What are telomeres?
Repeitive sequences of DNA found at the ends of chromosomes which are essential to cellular reproduction. They protect genes from damage and recombining with other DNA.
What is the telomere theory of aging?
The theory that as people age their telomeres become smaller and smaller (as telomeres get smaller for each cell replication) and thus cells are unable to replicate properly or as efficiently.
What is an autopsy?
A research method in which neuroscientists can observe what the brain looks like, however it proves no functional data.
What were the old neuroscience research methods?
Examining autopsy tissues, testing behaviour of patients with brain damage, recording brain waves and animal studies.
Why did neuroscientist test behaviour of brain damaged individuals?
To identify what regions of the brain are responsible for certain functions. This was not reliable as there was bias and the mind adapted over time.
How and why was brain activity/waves recorded?
They are recorded with an EEGs (electroencephalograms) to learn about brain activity during certain states/behaviours. The problem was that the data was too generalized and brain function could not be pinpointed.
What was done in animal studies?
Animal studies included close observations of brain structure, electrically recording certain brain areas and destroying certain parts of the brain in order to determine effects on behaviour. (Lesioning)
What is lesioning?
The process in which certain areas of the brain were destroyed in animals in order to identify the effect on behaviour of that area.
What is the main problem with all of the old neuroscience research methods?
They told us little about activity/function of the brain in healthy human brains.
What is the anterior cingulate?
A part of the frontal lobe that is responsible for the processing information about pain and difficult decision making
What is neuroimaging?
New techniques that are used to study the brain. The most useful techniques are the PET scan and fMRI.
What is the PET scan?
A neuroimaging technique detects uptake of certain molecules which indicate increased brain activity.
What is the fMRI?
A neuroimaging technique that detects change in blood flow which indicates increased activity within neurons.
What are the two major cells within the nervous system?
The neuron and glial cell (glia)
What are neurons?
The fundamental cell of the nervous system, they are responsible for the transmission and networking of information.
How do neurons communicate?
Through both chemical and electrical signals.
What are the features of the neuron?
The cell body (soma), dendrites, axon, synaptic terminal/cleft
What are dendrites?
Branches that collect information and send it to the cell body.
What is the soma?
The cell body of the neuron. It has a cytoplasm, nucleus, organelles, produces energy and breaks down waste/toxins.
What is the axon?
A pathway from the cell body that transmits information to the axon terminal.
What is the synaptic cleft or axon terminal?
It is the area where neurotransmitters are released into the synapses in order to communicate with other neurons.
What are the three types of neurons?
Motor, Sensory and Interneurons
What are sensory neurons?
Neurons that collect sensory information.
What are motor neurons?
Neurons that transmit information to muscles in order to do work.
What are interneurons?
Neurons that connect the sensory and motor neurons.
Are there more neurons in the body or glial cells?
There are 10x more glial cells than neurons.
What are glial cells or glia?
Cells that buffer neurons from the rest of the body, nurish neurons and remove dead/diseased neurons.
What are the five types of glial cells?
Astroglia, Oligodendrogli, Schwann Cells, Ependymal Cells and Microglia
What do astroglia do?
They are star shaped glia that create the blood-brain barrier, regulate blood flow, absorb/clean up chemicals in order to promote growth, migrate to sites of brain damage to form glial scars, absorb unneeded K+ ions and serve as stem cells.
What are oligodendroglia?
A type of glial cell that functions in the central nervous system. It creates myelin in the CNS. (In order to protect the neuron and speed up transmissions)
What are Schwann cells?
A type of glial cell that functions in the peripheral nervous system. It produces myelin (in order to protect the neuron and speed up transmission) along with digesting debris and guiding regrowth in the PNS axons.
What are ependymal cells?
A type of glial cell that specializes in lining the walls of the ventricles in the brain and creating cerebrospinal fluid in order to form the cerebrospinal fluid barrier.
What are microglia?
A small type of glial that cleans up debris of degenerating or dead neurons and protect the neuron from infection or illness.
What is the resting potential?
The voltage or electric change in a neuron at rest, usually -70mV.
What is an action potential?
The rapid reversal in voltage across the axon membrane that is caused by the exchange of ions, it requires a stimulus.
Explain how an action potential occurs.
A stimulus depolarizes the neuron beyond the threshold potential and sodium channels open, due to the concentration gradient, sodium floods into the cell and the membrane potential goes up to about 50mV. At this point, sodium channels close and potassium channels open, potassium ions flow out of the cell and the membrane is repolarized. (There is a refractory period as the repolarization overshoots the resting potential)
What does it mean to be depolarized?
To become more positive or less negative.
What does it mean to be repolarized?
To restore the lost negative charge, to become more negative or less positive.
What is the sodium potassium pump?
A mechanism that maintains the resting potential of a neuron by maintaining the concentration gradient of the ions. (High K+ inside, High Na+ outside) It pumps 3 Na+ out of the cell for every 2 K+ into the cell.
Can action potentials vary in strength?
No, they are an all or nothing mechanism.
How do you increase the intensity of a stimulus?
By increasing the quantity and frequency of neurons that fire.
What is myelin?
A white fatty substance that protects the neuron and increases the rate of transmission.
What are the nodes of Ranvier?
Gaps within the myelin sheet that increase rate of transmission.
What is saltatory conduction?
Myelined transmission of information where action potentials jump from node to node. (Faster)
What is continuous conduction?
Unmyelinated transmission of information where action potentials must travel the entire path of the axon rather than jumping from node to node. (Slower)
What is the absolute refractory period?
A short time after the action potential where the neuron cannot fire again no matter what.
What is the relative refractory period?
The time immediately after the absolute refractory period in which neurons can only fire again if an extremely strong stimulus is induced upon the neuron. (HIgher than normal threshold)
What are synapses?
The spaces between the pre-synaptic neuron and post-synaptic neuron. It is the junction where neurons communicate with one another.
What are neurotransmitters?
Chemicals that are released from the synaptic terminal which are used to communicate with other neurons.
What type of binding is done with neurotransmitters and their receptors?
A lock and key specificity method
What are the synaptic vesicles?
Membrane bound spheres that store neurotransmitters before they are released into the synapse.
How are neurotransmitters released?
As the action potential propogates down the neuron (axon), it eventually reaches the axon terminal and causes the synaptic vesicles to release the neurotransmitters across the synapses.
What are neurotransmitter receptors?
Proteins on the post-synaptic neuron that bind to the released neurotransmitters. (Very specific)
What is Glutamate?
A neurotransmitter responsible for learning, movement.
What is GABA?
A neurotransmitter responsible for learning and anxiety regulation.
What is Acetylcholine (ACh)?
A neurotransmitter responsible for learning and attention.
What is Dopamine?
A neurotransmitter responsible for movement and reward learning.
What is Serotonin?
A neurotransmitter responsible for mood regulation. Low levels lead to anxiety and depression.
What is norepinephrine?
A neurotransmitter responsible for attention and arousal.
What are postsynaptic potentials?
The response/electrical events that occur within the postsynaptic neuron once the neurotransmitters have binded to the receptors.
What are the two postsynaptic potentials?
Either excitatory or inhibitory.
If a neuron is excited what happens to its voltage?
It increases (depolarized) and the likelyhood of an action potential is increased as excitatory ion channels (Na, Ca) are opened.
If a neuron is inhibited what happens to its voltage?
It decreases (hyperpolarized) and the likelyhood of an action potential is reduced because either inhibitory ion channels are opened (K, Cl) are opened or excitatory ion channels are closed (Na, Ca).
What are gliotransmitters?
Chemicals released by glial cells that may cause long-term change within the postsynaptic membranes depending on exposure to excess or lack of exposure to certain neurotransmitters.
What is plasticity?
Changes within the nervous system or the ability of the brain to fix itself or repurpose neurons.
What is synpatic plasticity?
Changes within the synapses due to repeated release of neurotransmitters.
What are neural circuits or networks?
A collection of neurons that communicate with one another.
What are cell assemblies?
A network of neurons that work as an interconnected entity. It also strengthens syaptic connection as certain mental processes are repeated and builds units for memory and cognitive function.
What are the two major components of the nervous system?
The central nervous system (CNS) and peripheral nervous system (PNS).
What is the central nervous system made of?
The brain and spinal cord
What is the somatic nervous system?
The part of the peripheral nervous system that gathers sensory information from the body and sends motor information to the body. It requires the CNS
What is the autonomic nervous system?
The part of the nervous system that is unconcious and does not require the CNS.
What is the sympathetic nervous system?
The part of the autonomic nervous system that is responsible for the "fight or flight" and stress response of the body.
What is the peripheral nervous system made of?
The somatic nervous system and autonomic nervous system. (Which is made of the parasympathetic and sympathetic nervous system)
What is the parasympathetic nervous system?
The part of the autonomic nervous system that is responsible for the repairing and recovering the body. (Rest)
What is the spinal cord?
The portion of the CNS that extends from the ase of the brain and mediates sensory and motor information.
What is the reflex response?
When the pain stimulus is collected by the sensory neuron and transmitted to an interneuron (in the spinal cord) which proceeds to send motor information to the motor neuron in order to prevent more damage.
Why is the reflex response faster than the pain response?
It goes only from the sensory neuron to the spinal cord back to the motor neuron while the pain response must go all the way to the brain and back.
What are the consequences of spinal cord injuries?
The body is paralyzed at and down from the point in the spinal cord damage because sensory information and motor information is cut off.
What is quadriplegic?
When someone is paralyzed everywhere except for the head and neck due to spinal cord damage.
What are some attempts to fix spinal cord damage?
Scientist have tried to increase regeneration of axons and motor neurons. They have also tried to use stem cells in order to produce Schwann cells which can repair damage.
What are the three regions of the brain?
The hindbrain, midbrain and forebrain.
What is the hindbrain?
The part of the brain that is closest to the spinal cord, it contains the medulla, reticular formation, pons and cerebellum.
What is the medulla?
It is connected to the spinal cord and is essential in basic regulatory functions such as respiration and heart rate. It is critical for survival and normal functioning.
What is the reticular formation?
It is the structure in the brain that is important for sleep, wakefulness and the dream state. It is the major source of serotonin.
What are the pons?
The region above the medulla, it acts as a bridge between the forebrain and cerebellum. It is also involved in sleep, breathing, swallowing, eye movements, facial sensations and expression.
What is the locus coeruleus?
A part of the pons that uses the neurotransmitter norepinephrine.
What is the cerebellum?
A flower shaped component that is located at the back of the brain. It is important for smooth motor coordination and it also responsible for learning that involves movement.
What is the midbrain?
The region of that brain that is above the pons, it includes the substantia nigra, thalamus, hypothalamus, pituitary gland, amygdala, hippocampus, striatum and nucleus accumbens.
What is the substantia nigra?
It is the part of the brain that important for the fluidity and/or inhibition of movement and the creation of dopamine.
What is the thalamus?
The part of the brain that acts as a relay center for sensory information (except smell) and has two main compartments, LGN and MGN.
What is the LGN (lateral geniculate nucleus)?
The part of the thalamus that is responsible for relaying visual stimuli.
What is the MGN (medial geniculate nucleus)?
The part of the thalamus that is responsible for relaying auditory stimuli.
What is the hypothalamus?
It is the area of the brain located below the thalamus. It is reponsible for homeostasis, motvation (basic drives) and control of the endocrine system.
What is the pituitary gland?
A brain structure that stores hormones and plays a critical role in the endocrine system.
What is the amygdala?
A part of the brain that is located in the temporal lobe. It is involved in recognition, learning about fear and emotions. (Fear mostly, also positive)
What is the hippocampus?
The part of the brain responsible for learning spatial information and new information. It is the mjaor site of plasticity and is composed of regions and layers rather than collections of neurons or nuclei.
What is the limbic system and what is it composed of?
It is the system responsible for the regulation of motivation, emotion and memory. It includes the thalamus, hypothalamus, amygdala and hippocampus.
What is the striatum?
A region of the brain that works with the substantia nigra in order to produce fluid movements. It is also responsible for unconcious learning.
What is the nucleus accumbens?
The area of the brain that is important for motivation and reward learning. It uses doapmine.
What does subcortical?
Areas of the brain that are located below the neocortex.
What is the neocortex?
The area of the brain that is responsible for higher level thinking, it is divided into the frontal, parietal, occipital and temporal lobes.
What are the two regions of each lobe?
The primary sensory/motor area that is used to process basic information. (Unless information crosses over) The other part is the association cortex which is responsible for higher level functioning.
What is the occipital cortex?
The part of the neocortext that is very important for processing of visual information. (Located at the back of the skull)
What is the temporal cortex?
The part of the neocortext that is responsible for processing auditory information. (Located of the sides of the skull) It also is responsible for language comprehension and complex visual stimuli like faces.
What is Wernicke's area?
The part of the brain located in the temporal cortex that is responsible for the understanding of language. (Usually located on the left side of the brain)
What is the lateralization of function?
The belief that a particular ability is localized to one side of the brain.
What is the parietal cortex?
The part of the neocortex that is responsible for the processing of sensory information that is related to touch, complex visual information and locations. (Located on the top middle of head)
What is the somatosensory strip?
The part of the parietal lobe that is responsible for processing tactile information about different body parts.
What is the frontal cortex?
The part of the neocortex that is responsible for higher level thinking, speech fomation, movement and personality. (Located front of brain)
What is the primary motor strip?
The part of the frontal cortex that is responsible for control of voluntary movement.
What is Broca's area?
A part of the frontal cortex that is responsible for the formation of speech. (Usually on left side of brain)
What is the pre-frontal cortex?
The part of the frontal cortex that is located closest to the front of the head. It is involved in higher level thinking such as memory, moral reasoning, planning and short term memory.
What is the corpus callosum?
The part of the brain that connects the two hemispheres of the neocortex. (It allows them to communicate)
Does visual and motor information "cross over" when being processed and collected?
Yes, visual and motor action in the left side of the body is from or sent to the right side of the brain and vice versa.
Is brain size proportional to intelligence?
No, it is more closely related to the size of the body. However, extremely small or big brains can lead to mental deficiencies.
What is multiple sclerosis?
A neurological dieases that involes the demyelination or loss of myelin within neurons. This slows down transmission rates and lead to vision loss, pain and muscle weakness.
What is amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)?
A neurological disorder that is due to the degeneration of motor neurons. It starts with muscle weakness and ultimately leads to paralysis and death.
What is Parkinson's disease?
A neurological disease that occurs due to the death of dopaminergic neurons (in the substantia nigra) or lack of dopamine. It leads to tremors within the body.
What is Huntington's disease?
A genetic neurological disease that results from the death of neurons in the striatum which leads to lack of control in movement.
What are the five basic senses?
Touch, sound, sight, taste, smell
What is sensation?
The detection of stimuli using sensory systems.
What is perception?
The identification or recognition of a stimuli.
What are sensory receptor cells?
Cells that convert specific stimuli into neural impulses that are interpreted by the nervous system.
What is sensory transduction?
The process in which stimuli are converted into neural impulses.
What is the absolute threshold?
The minimum stimulus required for detection. (Notice 50% of time)
What is the difference threshold?
The minimal difference between two stimuli that distinguish them from one another.
What is sensory adaptation?
The process in which one adapts to a certain frequently experienced stimuli thus leading to a reduced response.
What is bottom-down processing?
Perception in which stimuli are transducted into neural signals and then moved to more complex brain regions.
What is top-down processing?
Perception that involves cognitive functions like memory or experience.
What are perceptual sets?
Perceptual expectations that bias us into perceiving certain things in certain ways.
What is the smell sense called?
Olfactory senses
What is the taste sense called?
Gustatory
What are odorants?
Chemicals that are detected as odour.
What are olfactory receptor neurons?
Sensory receptor cells that convert odorants into neural impulses that travel to the brain. (Located in the nasal mucosa)
How do olfacory receptor neurons bind to odorants?
Through a lock and key mechanism
What is flavour?
The blend between smell and taste
What are papillae?
Bumps on the tongue that contain taste buds/receptors.
What are taste buds?
Sensory receptor cells that covert chemicals from food into neural impulses that travel to the brain.
What are the five taste receptors?
Sweet, sour, bitter, salty and umami.
What is the olfactory bulb?
The first region in the pathway of olfactory information transmission to the brain.
What is the complete pathway for olfactory information?
Nose > Olfactory Bulb > Amygdala > Olfactory Cortex
Why do some odours stimulate memory?
Olfactory information passes through the amygdala which is responsible for memory and emotions.
What is the complete pathway for gustatory information?
Mouth > Thalamus > Gustatory Cortex
What is the insula?
The part of the cortext that receives taste information associated with the emotion of disgust.
What is anosmia?
The loss of the ability to smell
What is ageusia?
The loss of the ability to taste
What is the touch sense called?
Tactile information
What are free nerve endings?
Sensory receptors that detect touch, pressure, pain and temperature.
What are Meissner's corpuscles?
Sensory receptors that convert stimuli about tactile information on the fingertips, lips and palms.
What are Merkel's discs?
Sensory receptors that convert information about light to moderate pressure on skin.
What are Ruffini's end-organs?
Sensory receptors that respond to heavy pressure or joint movement.
What are Pacinian corpuscles?
Sensory receptors that respond to vibrations or heavy pressure.
What is the complete pathway for tactile information?
Receptor > Spinal Cord > Thalamus > Somatosensory Cortex
What does contralaterally mean?
It means that stimuli on one side of the body is processed on the other side of the brain.
Why do women generally feel more pain?
They have twice the amount of pain receptors in their facial skin than men.
What is the gate control theory of pain?
The theory that certain patterns of neural activity can inhibit gates to prevent pain information from travelling to the brain.
What are endorphins and enkephalins?
Chemicals that relieve pain.
What is cingulotomy?
The destruction of the cingulate cortex in order to remove pain.
What is familial dysautonomia?
A rare genetic condition where one cannot feel pain or temperature.
What is phantom sensations?
When an individual that has lost certain limbs can still feel reception or send signals to that missing area as it is still active in the somatosensory cortex.
What are the two major qualities of sound waves?
Frequency and Amplitude
What is frequency?
The number of cycles per second (Hz), it produces the pitch of sound.
What is amplitude?
The strength or loudness of a sound wave, it is measured in decibels (dB).
What is the tympanic membrane?
The ear drum and first area to be stimulated by auditory information.
What are ossicles?
Tiny bones within the ear, there is the maleus, incus, stapes.
What is the oval window?
A membrane that is stimulated by the stapes, it causes waves to form in the cochlea.
What is the cochlea?
The auditory organ, when it is stimulated by the oval window, the fluid within it stimulates hair cells.
What is the basilar membrane?
A membrane within the cochlea where hair cells are located.
What are hair cells?
Sensory receptors within the cochlea that convert sound waves into neural signals.
What is the path of auditory information?
Sound waves enter the ear and strimulate the tympanic membrane. Then the ossicles are stimulated and stapes eventually hits the oval window. The oval window creates waves within the cochlea that stimulate the hair cells within the basilar membrane. The hair cells communicates with the auditory nerve in order to send neural signals to the thalamus then to the auditory cortex.
What is the frequency theory of sound?
That different frequencies are interpreted as different sounds.
What is the place theory of sound?
That different frequencies stimulate different areas of the basilar membrane and thus different sounds are interpreted.
What is conduction deafness?
The loss of hearing because the pathway is blocked or ear drum is damaged.
What is nerve deafness?
The loss of hearing because of hair cell damage.
What is the cocktail party effect?
When the brain filters out useless information.
How is location of sound detected?
With general loudness, loudness in each ear and time difference between hearing in each ear.
What is the tonotopic map?
The representation of the auditory cortex according to different frequencies.
What is synesthesia?
When the senses of an individual are "mixed up." (Seeing noise or tasting words for example)
What is absolute pitch?
The rare ability to be able to recognize or produce any note/pitch on the musical scale.
What is amusia?
The inability to distinguish between different pitches or tones.
What is tinnitus?
The condition where there is constant ringing with the ear although there is no stimulus.
What is the stimuli for vision?
Electromagnetic radiation or light
What is the iris?
The part of the eye that controls opening of the pupil in order to monitor how much light enters the eye.
What are the lens?
The part of the eye that focuses light onto the retina.
What is the retina?
The part of the eye that contains photoreceptors.
What are photoreceptors?
Sensory receptors that collect visual information and transduce it into neural impulses.
What are the two photoreceptors?
Rods and cones
What are rods?
Photoreceptors that respond to the levels of light and dark or brightness.
What are cones?
Photoreceptors that respond to colours.
What is the optic nerve?
A bundle of axons of ganglion cells that transfer visual information to the brain from the eye.
How is vision detected?
When light reaches the photoceptors within the retina, rods and cones stimulate bipolar cells that cause ganglion cells to fire and travel out of the optic nerve into the brain.
What is the fovea?
The center of the retina which has a extremely high concentration of cones, thus where vision is most clear.
What are the three dimensions of coliur?
Hue, saturation and brightness
What is hue?
The colour aspect of light
What is saturation?
The purity of a colour
What is brightness?
The amount of light that is reflected by a colour.
What is the trichromatic theory of colour vision?
The theory that people have three different colour receptors (blue-purple , green, red-yellow) that are responsible for the intrepretation of colour.
What is the opponent process theory of colour vision?
The theory that believes that colour is intepreted because colour pairs work to inhibit one another.
What is the most common colour blindness?
Red-green colour blindness which the loss cones that respond to red and green light.
What is the full path of vision information?
Eye > Retina > Optic nerve > Superior Colliculus > Thalamus (LGN) > Occipital cortex
What are the two complex visual pathways?
The "what" pathway and the "where" pathway
What is the pathway for the "what" visual path?
Occipital Cortex > Temporal Cortex
What is the pathway for the "where" visual path?
Occipital Cortex > Parietal Cortex
What is visual agnosia?
Damage to the temporal cortex that distorts the "what pathway." People lose the ability to recognize objects visually.
What is prosopagnosia?
The loss of the ability to recognize faces due to damage in the "what" pathway.
What is hemi-neglect?
Damage to the "where" pathway which causes people to ignore one side of their visual field
What is retinal disparity?
The slight difference in images that are processed by the retinas of the eyes.
What is convergence?
When the eyes move inward in order to view extremely close objects.
What are monocular cues?
Visual cues that can be perceived with information from only one eye.
What are perceptual constancies?
Top-down tendencies that cause one to view objects as unchanging although there is stimuli.
What is strabismus?
The condition where one does not develop coordinated movements in both eyes.
What is amblyopia?
The condition that results from abnormal development within the visual cortex, it leads to the loss of vision within one eye.
What are the two other senses besides the basic five?
Vestibular and Kinesthetic
What is the Vestibular sense?
The sense that provides us with information about our body position and orientation.
What is the Kinesthetic sense?
The sense that tells us about our motion.