3 - Neuroscience and Behaviour Flashcards
Neurons
cells in nerv syst that comm with one another to perform infro processing tasks
Components of Neuron
cell body, dendrites, axon, meylin sheath, glial cells, synapse
Soma
cell body, largest comp. coordinates info process tasks and keeps cell alive through protein synth, energy prod, metabolism. has nucleus
dendrites
recieve info from other neurons and relay to cell body
axon
carries info to other neurons, muscles, or glands, can stretch up to a meter
Myelin sheath
insulating layer of fatty material. without myelin, transmission of info slows down
glial cells
support cells found in nerv. system. so many, perfomring diff tasks (digest parts of dead neurons, provide physical and nutritional supports for neurons, form myelin)
synapse
the junction or region between the axon of one neuron and dendrite/cell body of another
Major types of neurons
sensory, motor, interneurons
sensory neurons
recieve info from external world and convery this info to brain via spinal cord
motor neurons
carry signals from spinal cord to muscles to produce movement
interneurons
connect sensory neurons, motor neurons, or other interneurosn. most of nerv. syst. made up of these.
conduction
movement of elec. sig. within neurons, from dendrites to fcell body throughout axon
transmission
movement of electric signals from one neuron to another over synapse
electrochemical action
conduction + transmission
resting potential
difference in elect charge between inside and outside of neuron’s cell membran
which ions are inside the neuron, which are outside?
K+ and A- (protein) inside
Na+ and Cl- outside
action potential process
resting: k+ can flow freely, Na+ kept inside, negative charge on inside
action: K+ channels close and Na+ opens, Na+ rushes in, increases the positive charage inside the axon (rel. to outside), triggering action potential
back to resting: imbalance in ions reversed by pump, moves Na+ outside the neuron and K+ inside
action potential
an electric signal that is conducted along the length of a neuron’s axon to the synapse
all or none
action potential is either there or it’s not
refractory period
time following an action potential during which a new action potential cannot be initiated
Nodes of Ranvier
breaks between the clumps of myelin
saltatory conduction
electric current passes down length of myelinated acon, charge jumps from node to node rather than transverse the entire axon, helps speed the flow of info
terminal buttons
knob like structures that branch out from an axon
neurotransmitters
chemicals contianed within vesicles that transmit info across the sunapse to a recieving neuron’s dendrites
receptors
parts of the cell membrane that recieve neurotransmitters and either intitate or prevent a new electric sign
postsynaptic neuron
recieving neuron
synaptic transmission
allows neurons to communicate with one anothr
describe process of synaptic transmission
action potential down acon, stim. release of neurontransmitters from besicles, nt released into synapse, bind with receptors sites on dendrite of ps neuron, initiate ap, nt cleared out of synapse by reuptake into the senidng neuron, broken down by enzymes in syapse, or binding autoreceptors on the sending neron
ACh
acetylcholine; nt incolved in many functions, including voluntary motor control
dopamine
nt that regulates motor behaviour, motivation, pleasure, emotional arousal
glutamate
major excitatory nt in the brain
GABA
gamma-aminobutyric acid; primary inhibatory nt in brain
norepinephrine
neurotransmitter that is particularily incolved in states of vigilance, heightened awareness of dangers in the environment
serotonin
nt that is involved in the regulation of sleep and wakefullness, eating and agrressive behaviour
endorphins
chemicals that act iwhtin the pain pathways and emotion centers of the brain
agonists
drugs that increase action of nt
antagonists
drugs that block the funtion of nt
L-dopa
developed to treat parkinsons, acts as agonist for dopamine, long time users see decrease in effectiveness
Amphetamine
drug that stimulates the release of norephinephrine and dopamine, prevent reuptake of them
cocaine
prevents reuptake of norephinephrine and dopamine
Methamphetamine
variant of amphetamine, affects pathways for dopamine, seretonin, norepinephrine in synapse; combined effect of agonist and antagonist alters function of nt and sometimes results in strange hallucinations
Prozac
commonly used to treat depression, agonist, blocks reuptake of nt serotonin. part of category of SSRI (selective seretonin reuptake inhibitors)
beta blockers
obstruct receptor site for norpinephrine in the heart
Propranalol
beta blocker
Nervous systems
interacting network of neurons that coveys electrochemical info throughout th ebody
CNS
central nervous system, composed of brain and spinal cord
PNS
peripheral nervous system, conenects the CNS to body’s organs and muscles
subdivisions of PNS
somatic and autonomic nervous sytems
somatic nervous system
conveys info between voluntary muslces and CNS
autonomic nervous system
carries involuntary and automatic commads that control blood vessels, body organs, and glands
subdivisions of ANS
sympathetic and parasympathetic
sympathetic nervous system
set of nerves that prepares body for action in challneging or threatenng situations
paraympathetic nervous systme
helps body return to normal resting state
Spinal reflexes
simple pathways in nervous systems that repidly generate muscle contractons
Hindbrain
area of brain that coordinates info coming in and out of spinal cord, control sbasic function of life like breathing, alterness, and motor skills
Medulla
extension of the spinal cord into the skull that coordinates heart rate circulation, and repsiration
reticular fomation,
regulates sleep, wakefulness and levels of arousal
cerebellum
a large structure of the hindbrain that controls fine motor skills
pons
a structure that relays information from the cerebellum to the rest of the brain (means bridge in Latin)
Midbrain (and parts of)
relatively small in humans, tetum and tegmentum
tectum
orinets an organism in the environment. recieves stimulus input from eyes, ear, skin and moves the organism in coordinated way towards the stimulus (turning towards a door when you hear the door click)
tementum
involved in movement and arousal, also helps orinet an organism toward sensory stimuli
Can you live with only the hind and mid brain?
yes. hindbrain = bodily functions necessary to sustain life, midbrain would orient you toward/away pleasurable/threatening stimuli in environment
forebrain
highest leel of brain, conrtols complex cognitive, emotional, sensory, and motor functions
divisions of forebrain
cerebral cortex and subcortical structures
cerebral cortext
outermost layer of brain, visible to the naked eye, and divided into two hemispheres
subcortical structures
areeas of the forebrain housed under the cerebral cortex near the center of the brain
Thalamus
relays and filters information from the senses and transmits the information to the cerebral cortex
Hypothalamus
(hypo = under in Greek) regultes body temp, hunger, thirst, sexual beahiour. small in size
pituitary gland
msater gland of the body’s hormone producing system, which releases hormons that direct the dunctions of many other glands in the body
subcoritcal structures
[thalamus, hypothalamus, pituitary] [limbic system] [basal ganglia]
limbic system
a group of forebrain structures including the hypothalamus, hippocampus, amygdala, which are involved in motivation, emtion, learning, and memory
hippocampus
(latin for sea horse, due to its shape), critical for creating new memories and integrating them into a network of knowledge so that they can be storied indefinitely in other parts of the cervral cortex
amygdala
(latin for almond, due to its shape), located at the tip of each horn of the hippocampus, plays a central role in many emotional processes, particularily the formation of emotional memories
basal ganglia
set of subcortical structures that directs intentional movements.
striatum
involved in control of posture and movement
gyrus
smooth surgaces of the cortext - the raised part (gyri = pl)
sulcus
indentations or fissures of the cortex (sulci = pl)
Newspaper analogy
more surface area fits in small space in crumpled newspaper vs flat newspaper
contralteral control
right cerebral hemisphere perceives stimuli from and control movements on left side of body, vice versa
commissures
bundles of axons that make possible communivation between parallel areas of the cortex in each hald
corpus callosum
largest commissures, connects large areas of the cerebral cortex on each side of the brain and supports communication of information across the hemispheres
occipital lobe
located at back of cerebreal corex, processes visual info
parietal lobe
in front of occipital lobe, carries out functions that include processing information about touch
somatosensory cortex
strip of brain tissues running from the top of brain down to side in the parietal lobe, each part maps onto a particular part of the body. body area = more sensitive, then more somatosensory cortex is devoted to it
homunculus
(little man), bdoy parts renderd according to how much of the somatosnsory cortex is deovted to them
motor cortex
parallel strip of brain tissue directly in front of the somatosensory cortex in frontal lobe, initiates voluntary moevements and sends messages to the basal ganglia, cerebellum, and spinal cord. like somatrosensory cortex,, certain areas corespond with different body parts
temporal lobe
lower side of hemisphere, responsible for hearing and language
primary auditory cortex
temporal lobe, analogous to somatosensory cortex in parietal lobe and the primary visual areas of occipital lobe. recieves senosry info from ears based on frequencies of sounds.
frontal lobe
sits behind forehead, specialized areas for movement, abstract thinking, planning, memory, and judgement
association areas
composed of neurons that help provide sense and meaning to information registered in the cortex
mirror neurons
active when an animal performs a behaviour such as reaching for or manipulating an object, and are also activated when another animal observes that animal performing the same behaviour
plasticity
the capacity of the sensory cortices for adaption to changes in senosry inputs
Broca’s area and Wernicke’s area
Broca - patient lost capacity to produce spoken language (but not understand it) due to damage to small area in left frontal lobe
Wenicke - impairment in language comprehension (but to production of) due to damage to area in upper-left temporal lobe
provided earliest evidence that brain locations for speech production and comprehension are separate, and that for most people, the left hemisphere is crtical to producing and understanding language
Phineas Gage
Rod through lower left jaw, exit through middle of top of head. Before accident, had been mild, quiet, conscientious, hard worker
After accident, irritable, irresponsible, indecisive, prone to profanity
Allowed researchers to investigate the hypothesis that the frontal lobe is involved in emoiton regulation, planning, and deciision making
Better able to understand how the amyfdala, hippocampus, and related brain structures interacted with the cerebral cortex
Seizures
one hemisphere cross the corpus callosum to the opposite hemisphere and starts a feedback loop that results in a kind of firestorm in the brain
Split brain procedure
cutting the corpus callosum, thereby isolating each hemisphere; produces some unusual behaviours
EEG
electroencephalograph, used to record electrical activity in the brain
feature dectecotrs
selectively respond to certain aspects of a visual image
Structural brain imaging
provides information about the basic structure of the brain, allows clinicians or researchers to see abnormalities in the brain structure
functional brain imaging
provides information baout the activity of the brain when people perform various kinds of cognitive or motor tasks
CT
computerized axial tomography scan; scanner rotates a device around head and takes series of Xray photos from different angles, usually used to locate lesions or tumours
MRI
magnetic resonance imaging; strong magnetic field to line up the nuclei of specific moleculres in the brain tissue. pulses of radio waves cause the nuclei to rotate out of alignment. When pulse ends, nclei snaps back in line with mgnetic field and gives off small amount of energy. can produce better pictures of soft tissue, gives picture of strucutre of brain and localize brain damae, but revelas nothng about the function so fbrain
DTI
Diffusion tensor imaging; type of MRI used to visualize white matter pathways, which are fibre bundles that connect both nearby and sitant brain regions to one another. Measures the rate and direction of diffusion or movement of water molecules along white matter pathways. Diffusion of water molecules follows direction of pathway. can also measure the rate and direction of diffusion to asses integrity of white matter pathway
PET
positron emission tomography; radioactive substance is inhected into bloodstream, brain is scanned by raiation detectors while person performs perceptual or cognitive tasks such as reading or speaking. areas of brain that are activated during these tasks demand more energy and greater blood flower, resulting in a hgher amount of radioactivity
fMRI
functional magnetic resonance imaging; detcts the differencebetween oxygenated hemoglobin and deoxygenated hemoglobin when exposed to magnetic pulses. shows level of activation in each brain area.
advantages of fMRI vs PET
does not require any exposure to radioactive substance, can localize changes in brain activity across briefer periods, which means it is more useful when analyzing quicker processes like reading a word or recognizing a face
resting state functional connectivity
measures the extent to which spontaneous activity in different brain regions is correlated over time. brain regions whose activity is highly correlated to each other are thought to be functionally connected with one another
brain networks
sets of brain regions that are closely connected to one another
default network
a group of interconnected regions in the frontal, temporal, and parietal lobes that is involved in internally focused cognitive activities like remembering past events, imagining future ones, daydreaming, and mind wandering
TMS
transcranial megnetic stimulation; mimics brain damage with benign technique. delivers magnetic pulse that passes through skill and deactivates neurons in cerebral cortex for short period
