CENTRAL NERVOUS SYSTEM Flashcards
1
Q
CNS
A
• BRAIN and SPINE
Its ‘neighbourhoods’ are collections of neuronal cell bodies called nuclei (the plural of nucleus).
• The ‘freeways’ of the CNS are made up of axons that travel together in bundles called fibre tracts or pathways.
2
Q
• BRAIN and SPINE
Its ‘neighbourhoods’ are collections of neuronal cell bodies called nuclei (the plural of nucleus).
• The ‘freeways’ of the CNS are made up of axons that travel together in bundles called fibre tracts or pathways.
A
CNS
3
Q
SPINAL CORD
A
- the part of the CNS within the spinal column that relays signals from peripheral senses to the brain and
- conveys messages from the brain to the rest of the body
- Neurons in the spinal cord also carry signals downwards, from the brain to the muscles
4
Q
- the part of the CNS within the spinal column that relays signals from peripheral senses to the brain and
- conveys messages from the brain to the rest of the body
- Neurons in the spinal cord also carry signals downwards, from the brain to the muscles
A
SPINAL CORD
5
Q
REFLEXES
A
- simple, involuntary, unlearned behaviours directed by the spinal cord without instructions from the brain
- they do send action potentials along fibre tracts going to the brain, however (you know you’ve been burned)
- sensory neurons = afferent neurons (towards)
- motor neurons = efferent (away)
6
Q
- simple, involuntary, unlearned behaviours directed by the spinal cord without instructions from the brain
- they do send action potentials along fibre tracts going to the brain, however (you know you’ve been burned)
- sensory neurons = afferent neurons (towards)
- motor neurons = efferent (away)
A
REFLEXES
7
Q
BRAIN
A
most complex part of CNS
8
Q
most complex part of CNS
A
BRAIN
9
Q
HINDBRAIN
A
- an extension of the spinal cord contained inside the skull where nuclei control blood pressure, heart rate, breathing and other vital functions
- signals coming from the spinal cord reach the hindbrain first
- malfunction = faint upon standing
10
Q
- an extension of the spinal cord contained inside the skull where nuclei control blood pressure, heart rate, breathing and other vital functions
- signals coming from the spinal cord reach the hindbrain first
- malfunction = faint upon standing
A
HINDBRAIN
11
Q
MEDULLA OBLONGATA
A
• an area in the hindbrain that controls blood pressure, heart rate, breathing and other vital (autonomic) functions
12
Q
• an area in the hindbrain that controls blood pressure, heart rate, breathing and other vital (autonomic) functions
A
MEDULLA OBLONGATA
13
Q
RETICULAR FORMATION
A
- a collection of cells and fibres in the hindbrain and midbrain that are involved in arousal and attention
- alters activity in rest of brain – arousal and attention
- malfunction = coma
14
Q
- a collection of cells and fibres in the hindbrain and midbrain that are involved in arousal and attention
- alters activity in rest of brain – arousal and attention
- malfunction = coma
A
RETICULAR FORMATION
15
Q
- ‘blue spot’
- a small nucleus in the reticular formation that is involved in directing attention particularly towards important stimuli in the environment
- malfunction = depression, ADHD, sleep disorder and PTSD
A
LOCUS COERULEUS
16
Q
LOCUS COERULEUS
A
- ‘blue spot’
- a small nucleus in the reticular formation that is involved in directing attention particularly towards important stimuli in the environment
- malfunction = depression, ADHD, sleep disorder and PTSD
17
Q
CEREBELLUM
A
- the part of the hindbrain whose main functions include controlling finely coordinated movements and storing memories about movement, but also
- activities not related to movement: memory, impulse control, pain, emotion and language etc.
- important in timing – timing speech and not stuttering
- disfunction = being mute, loss of balance & coordination when walking
18
Q
- the part of the hindbrain whose main functions include controlling finely coordinated movements and storing memories about movement, but also
- activities not related to movement: memory, impulse control, pain, emotion and language etc.
- important in timing – timing speech and not stuttering
- disfunction = being mute, loss of balance & coordination when walking
A
CEREBELLUM
19
Q
MIDBRAIN
A
- a small structure between the hindbrain and forebrain that relays information from the eyes, ears and skin and that controls certain types of automatic behaviour
- jumping rope, moving head without vision blurring
- important nucleus present there: substantia nigra, connected to striatum
20
Q
- a small structure between the hindbrain and forebrain that relays information from the eyes, ears and skin and that controls certain types of automatic behaviour
- jumping rope, moving head without vision blurring
- important nucleus present there: substantia nigra, connected to striatum
A
MIDBRAIN
21
Q
SUBSTANTIA NIGRA
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• an area of the midbrain involved in initiating smooth movements
22
Q
• an area of the midbrain involved in initiating smooth movements
A
SUBSTANTIA NIGRA
23
Q
STRIATUM
A
• a structure within the forebrain that is involved in the smooth beginning of movement
24
Q
• a structure within the forebrain that is involved in the smooth beginning of movement
A
STRIATUM
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FOREBRAIN
* covers rest of brain
* the most highly developed part of the brain;
* it is responsible for the most complex aspects of behaviour and mental life
* hypothalamus; corpus collosum; cerebral cortex; striatum. Thalamus; septum; amygdala; hippocampus
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* covers rest of brain
* the most highly developed part of the brain;
* it is responsible for the most complex aspects of behaviour and mental life
* hypothalamus; corpus collosum; cerebral cortex; striatum. Thalamus; septum; amygdala; hippocampus
FOREBRAIN
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THALAMUS
* a forebrain structure that relays signals from most sense organs to higher levels in the brain; and
* plays an important role in processing and making sense out of this information
* (interprets and relays sensory information)
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* a forebrain structure that relays signals from most sense organs to higher levels in the brain; and
* plays an important role in processing and making sense out of this information
* (interprets and relays sensory information)
THALAMUS
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HYPOTHALAMUS
* a structure in the forebrain that regulates hunger, thirst and sex drive
* connected to autonomic NS
* disfunction = urge to eat / sexual disfunction
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* a structure in the forebrain that regulates hunger, thirst and sex drive
* connected to autonomic NS
* disfunction = urge to eat / sexual disfunction
HYPOTHALAMUS
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SUPRACHAIASMATIC NUCLEI
* nuclei in the hypothalamus (24 hr clock) that generate biological rhythms – waking, sleeping, cycles of body temperature
* different energy levels at different times of day
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* nuclei in the hypothalamus (24 hr clock) that generate biological rhythms – waking, sleeping, cycles of body temperature
* different energy levels at different times of day
SUPRACHAIASMATIC NUCLEI
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AMYGDALA
* part of the LIMBIC SYSTEM
* a structure in the forebrain
* fear and reward learning
* associates features of stimuli from 2 different senses (connects sensation and emotion)
* Disfunction associated with PTSD
* Influences strength of reaction to facial expressions and ability to discriminate
34
* part of the LIMBIC SYSTEM
* a structure in the forebrain
* fear and reward learning
* associates features of stimuli from 2 different senses (connects sensation and emotion)
* Disfunction associated with PTSD
* Influences strength of reaction to facial expressions and ability to discriminate
AMYGDALA
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HIPPOCAMPUS
* a structure in the forebrain
* the formation of new memories,
* but not solely responsible for storing them
* damage = anterograde amnesia (inability to build new memories)
* its size and neuron activity determines memory efficiency
* trauma = loss of neurons = reduces volume of hippo.
* Assoc. btw. Depression/PTSD and damage
36
* a structure in the forebrain
* the formation of new memories,
* but not solely responsible for storing them
* damage = anterograde amnesia (inability to build new memories)
* its size and neuron activity determines memory efficiency
* trauma = loss of neurons = reduces volume of hippo.
* Assoc. btw. Depression/PTSD and damage
HIPPOCAMPUS
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LIMBIC SYSTEM
* hippocampus & amygdala
| * a set of brain structures that play important roles in regulating emotion and memory
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* hippocampus & amygdala
| * a set of brain structures that play important roles in regulating emotion and memory
LIMBIC SYSTEM
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DEMENTIA
• caused by Alzheimer’s: degeneration of neurons in regions of the hippocampus and other limbic and cortical structures
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• caused by Alzheimer’s: degeneration of neurons in regions of the hippocampus and other limbic and cortical structures
DEMENTIA
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CEREBRAL CORTEX
* outermost surface of brain
* consists of 2 cerebral hemispheres
* 2500 square cm., has folds
* Analyses sensory information; controls voluntary movements, abstract thinking and other complex cognitive activity
* ANATOMICAL AREAS: frontal, temporal, parietal, occipital lobes
* FUNCTIONAL AREAS: Association cortex; motor cortex; somatosensory cortex, association cortex; broca’s area; auditory cortex; wernicke’s area; visual cortex.
42
* outermost surface of brain
* consists of 2 cerebral hemispheres
* 2500 square cm., has folds
* Analyses sensory information; controls voluntary movements, abstract thinking and other complex cognitive activity
* ANATOMICAL AREAS: frontal, temporal, parietal, occipital lobes
* FUNCTIONAL AREAS: Association cortex; motor cortex; somatosensory cortex, association cortex; broca’s area; auditory cortex; wernicke’s area; visual cortex.
CEREBRAL CORTEX
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CEREBRAL CORTEX
* outermost surface of brain
* consists of 2 cerebral hemispheres
* 2500 square cm., has folds
* Analyses sensory information; controls voluntary movements, abstract thinking and other complex cognitive activity
* ANATOMICAL AREAS: frontal, temporal, parietal, occipital lobes
* FUNCTIONAL AREAS: Association cortex; motor cortex; somatosensory cortex, association cortex; broca’s area; auditory cortex; wernicke’s area; visual cortex.
44
* outermost surface of brain
* consists of 2 cerebral hemispheres
* 2500 square cm., has folds
* Analyses sensory information; controls voluntary movements, abstract thinking and other complex cognitive activity
* ANATOMICAL AREAS: frontal, temporal, parietal, occipital lobes
* FUNCTIONAL AREAS: Association cortex; motor cortex; somatosensory cortex, association cortex; broca’s area; auditory cortex; wernicke’s area; visual cortex.
CEREBRAL CORTEX
45
SENSORY CORTEX
* the parts of the cerebral cortex that receive stimulus information from the senses
* Visual cortex; auditory cortex; somatosensory cortex.
* The amount of sensory cortex that responds to particular sensory inputs can be changed by experience
* E.g. Practicing violin, more neurons in somatosensory cortex (finger touches); phantom limbs
46
* the parts of the cerebral cortex that receive stimulus information from the senses
* Visual cortex; auditory cortex; somatosensory cortex.
* The amount of sensory cortex that responds to particular sensory inputs can be changed by experience
* E.g. Practicing violin, more neurons in somatosensory cortex (finger touches); phantom limbs
SENSORY CORTEX
47
MOTOR CORTEX
* the part of the cerebral cortex whose neurons control voluntary movements in specific parts of the body
* frontal lobe
* specific muscles in those regions linked to patterned activity of many neurons (not specific neurons)
* m. cortex first translates an object’s location in space relates to the body
* then which muscles must be contracted
* then populations of neurons work together to produce just the right combination of direction and force in the particular muscle groups needed
48
* the part of the cerebral cortex whose neurons control voluntary movements in specific parts of the body
* frontal lobe
* specific muscles in those regions linked to patterned activity of many neurons (not specific neurons)
* m. cortex first translates an object’s location in space relates to the body
* then which muscles must be contracted
* then populations of neurons work together to produce just the right combination of direction and force in the particular muscle groups needed
MOTOR CORTEX
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ASSOCIATION CORTEX
* parts of the cerebral cortex that receive information from more than one sense or that combine sensory and motor information to perform complex cognitive tasks
* e.g. associating words with images
* Malfunction: aphasia, difficulty in understanding or producing speech
* Languages involves activity in different parts of cerebral cortex: auditory (comprehending spoken language), visual (written), motor (speaking). But association cortex also important
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* parts of the cerebral cortex that receive information from more than one sense or that combine sensory and motor information to perform complex cognitive tasks
* e.g. associating words with images
* Malfunction: aphasia, difficulty in understanding or producing speech
* Languages involves activity in different parts of cerebral cortex: auditory (comprehending spoken language), visual (written), motor (speaking). But association cortex also important
ASSOCIATION CORTEX
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DAMAGE TO ASSOCIATION CORTEX
* Broca’s aphasia = difficulty speaking ,slow speech, words come out incorrect
* Wernicke’s damage = interpretation of speech and written word. Can’t understand words or speak understandably (but can speak)
* Broca’s: halting and ungrammatical, but meaningful speech
* Wernicke’s: fluent speech without meaning.
* The particular areas of the association cortex that are activated depend on whether language is spoken or written and whether particular grammatical, conceptual categories are involved
* Foreign accent syndrome
52
* Broca’s aphasia = difficulty speaking ,slow speech, words come out incorrect
* Wernicke’s damage = interpretation of speech and written word. Can’t understand words or speak understandably (but can speak)
* Broca’s: halting and ungrammatical, but meaningful speech
* Wernicke’s: fluent speech without meaning.
* The particular areas of the association cortex that are activated depend on whether language is spoken or written and whether particular grammatical, conceptual categories are involved
* Foreign accent syndrome
DAMAGE TO ASSOCIATION CORTEX
53
PREFRONTAL CORTEX
* Complex processes nec. for conscious control of thoughts and actions for understanding the world
* Allow us to understand sarcasm/irony
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* Complex processes nec. for conscious control of thoughts and actions for understanding the world
* Allow us to understand sarcasm/irony
PREFRONTAL CORTEX
55
EEG
* Electroencephalography
* Charting electrical fields from activity of billions of neurons
* + Detects very rapid changes in electrical activity, allowing analysis of stages of cognitive processing
* -- Provides poor spatial resolution of the source of electrical activity; EEG is sometimes combined with magnetoencephalography (MEG), which localises electrical activity by measuring magnetic fields associated with it
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* Electroencephalography
* Charting electrical fields from activity of billions of neurons
* + Detects very rapid changes in electrical activity, allowing analysis of stages of cognitive processing
* -- Provides poor spatial resolution of the source of electrical activity; EEG is sometimes combined with magnetoencephalography (MEG), which localises electrical activity by measuring magnetic fields associated with it
EEG
57
PET
* position emission tomography scan
* can locate cell activity by recording where substances such as glucose or other cellular fuels become concentrated after being made radioactive and injected into the bloodstream
* used: neurotransmitters, drugs or tracer for blood flow or glucose use (indicating speicifc changes in neuronal activity)
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• position emission tomography scan
• can locate cell activity by recording where substances such as glucose or other cellular fuels become concentrated after being made radioactive and injected into the bloodstream
• used: neurotransmitters, drugs or tracer for blood flow or glucose use (indicating speicifc changes in neuronal activity)
•
PET
59
PET DIS/ADVANTAGES
+ Allows functional and biochemical studies 1 Provides visual image corresponding to anatomy 2 Requires exposure to low levels of radioactivity 2 Provides spatial resolution better than that of EEG but poorer than that of MRI
• -- Cannot follow rapid changes (those faster than 30 seconds
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* + Allows functional and biochemical studies 1 Provides visual image corresponding to anatomy 2 Requires exposure to low levels of radioactivity 2 Provides spatial resolution better than that of EEG but poorer than that of MRI
* -- Cannot follow rapid changes (those faster than 30 seconds
PET DIS/ADVANTAGES
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MRI
* magnetic resonance imaging
* exposes the brain to a magnetic field and measures the resulting radio frequency waves to get amazingly clear pictures of the brain’s anatomical details
* detects changes in blood flow that reflect ongoing changes in activity of neurons – ‘moving picture’ of brain
* Traditional MRI provides high-resolution image of brain anatomy.
* Functional MRI (fMRI) provides images of changes in blood flow (which indicate specific changes in neural activity).
* A newer variant, diffusion tensor imaging (DTI), shows water flow in neural fibres (axon pathways), thus revealing the ‘wiring diagram’ of neural connections in the brain
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* magnetic resonance imaging
* exposes the brain to a magnetic field and measures the resulting radio frequency waves to get amazingly clear pictures of the brain’s anatomical details
* detects changes in blood flow that reflect ongoing changes in activity of neurons – ‘moving picture’ of brain
* Traditional MRI provides high-resolution image of brain anatomy.
* Functional MRI (fMRI) provides images of changes in blood flow (which indicate specific changes in neural activity).
* A newer variant, diffusion tensor imaging (DTI), shows water flow in neural fibres (axon pathways), thus revealing the ‘wiring diagram’ of neural connections in the brain
MRI
63
MRI DIS/ADVANTAGES
* + Requires no exposure to radioactivity
* + Provides high spatial resolution of anatomical details (smaller than 1 millimetre)
* -- fMRI is currently very expensive and therefore not always practical for extensive research
* -- Traditional MRI provides only spatial information (i.e., anatomy only), and although fMRI provides some temporal information (i.e., about neural activity over time), it cannot follow rapid change
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* + Requires no exposure to radioactivity
* + Provides high spatial resolution of anatomical details (smaller than 1 millimetre)
* -- fMRI is currently very expensive and therefore not always practical for extensive research
* -- Traditional MRI provides only spatial information (i.e., anatomy only), and although fMRI provides some temporal information (i.e., about neural activity over time), it cannot follow rapid change
MRI DIS/ADVANTAGES
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TMS
* transcranial magnetic stimulation
* variation on fMRI
* uses strong magnetic fields to temporarily stimulate or disrupt the activity of neurons in a particular region of the brain
* Normal function of a particular brain region can be studied by observing changes after TMS is applied to a specific location
* two techniques can be combined, so if one region is stimulated by TMS and fMRI shows changes occurring in another region, this indicates that the functions occurring in the two regions are connected
* + Shows which brain regions are necessary for given tasks
* -- Long-term safety not well established
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* transcranial magnetic stimulation
* variation on fMRI
* uses strong magnetic fields to temporarily stimulate or disrupt the activity of neurons in a particular region of the brain
* Normal function of a particular brain region can be studied by observing changes after TMS is applied to a specific location
* two techniques can be combined, so if one region is stimulated by TMS and fMRI shows changes occurring in another region, this indicates that the functions occurring in the two regions are connected
* + Shows which brain regions are necessary for given tasks
* -- Long-term safety not well established
TMS
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MIRROR NEURON MECHANISMS
* Neurons in area called F5 are activated not only when a monkey plans to reach for an object, such as a peanut, but also if the monkey sees an experimenter reach for one
* Broca’s area contains a mirroring mechanism: brain lights up when guitar student watches someone play guitar
* Another area =emotions. Brain lights up when you see someone experiencing disgust, in the same area of your brain
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* Neurons in area called F5 are activated not only when a monkey plans to reach for an object, such as a peanut, but also if the monkey sees an experimenter reach for one
* Broca’s area contains a mirroring mechanism: brain lights up when guitar student watches someone play guitar
* Another area =emotions. Brain lights up when you see someone experiencing disgust, in the same area of your brain
MIRROR NEURON MECHANISMS
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DIVIDED BRAIN
• Left hemisphere contains right side of body and vice versa
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• Left hemisphere contains right side of body and vice versa
DIVIDED BRAIN
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LATERAL DOMINANCE
• the tendency for one cerebral hemisphere to excel at a particular function or skill compared with the other hemisphere
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• the tendency for one cerebral hemisphere to excel at a particular function or skill compared with the other hemisphere
LATERAL DOMINANCE
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CORPUS CALLOSUM
* a massive bundle of fibres that connects the right and left cerebral hemispheres and allows them to communicate with each other (transfers info btw. them)
* usually integrates the functions of the ‘two brains’
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* a massive bundle of fibres that connects the right and left cerebral hemispheres and allows them to communicate with each other (transfers info btw. them)
* usually integrates the functions of the ‘two brains’
CORPUS CALLOSUM
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RIGHT HEMISPHERE
* self-awareness and normal learning abilities
* it is superior to the left hemisphere on tasks dealing with spatial relations (especially drawing three-dimensional shapes) and at recognising human faces.
* better spatial, artistic and musical abilities
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* self-awareness and normal learning abilities
* it is superior to the left hemisphere on tasks dealing with spatial relations (especially drawing three-dimensional shapes) and at recognising human faces.
* better spatial, artistic and musical abilities
RIGHT HEMISPHERE
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LEFT HEMISPHERE
* better logical and language abilities
* the language abilities of the left hemisphere are not specifically related to auditory information
* The precise nature and degree of lateralisation vary quite a bit among individuals.
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* better logical and language abilities
* the language abilities of the left hemisphere are not specifically related to auditory information
* The precise nature and degree of lateralisation vary quite a bit among individuals.
LEFT HEMISPHERE
79
SEX DIFFERENCES IN LATERALISATION
* sex differences tend to be quite small
| * Damage to just one side of the brain is more disabling to men than to women, esp. language
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* sex differences tend to be quite small
| * Damage to just one side of the brain is more disabling to men than to women, esp. language
SEX DIFFERENCES IN LATERALISATION
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NEURAL PLASTICITY IN THE CNS
* the ability of the CNS to create new synapses and to change the strength of synapses
* depends on neurons and glial cells
* provides basis for learning & memory
* brain scanning tech means you can chart it
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* the ability of the CNS to create new synapses and to change the strength of synapses
* depends on neurons and glial cells
* provides basis for learning & memory
* brain scanning tech means you can chart it
NEURAL PLASTICITY IN THE CNS
83
NEURAL PLASTICITY IN THE CNS
* the ability of the CNS to create new synapses and to change the strength of synapses
* depends on neurons and glial cells
* provides basis for learning & memory
* brain scanning tech means you can chart it
84
* the ability of the CNS to create new synapses and to change the strength of synapses
* depends on neurons and glial cells
* provides basis for learning & memory
* brain scanning tech means you can chart it
NEURAL PLASTICITY IN THE CNS
85
REPAIRING BRAIN DAMAGE
* Undamaged neurons may take over for damaged ones, partly by changing their own function and partly by sprouting axons whose connections help neighbouring regions take on new functions
* These changes rarely result in complete restoration of lost functions tho
86
* Undamaged neurons may take over for damaged ones, partly by changing their own function and partly by sprouting axons whose connections help neighbouring regions take on new functions
* These changes rarely result in complete restoration of lost functions tho
REPAIRING BRAIN DAMAGE
87
TRANSPLANTS
* Scientists are searching for ways to help a damaged central nervous system heal some of its own wounds. One approach has been to transplant, or graft, tissue from a still-developing foetal animal brain (aborted foetuses) into the brain of an adult animal (person)
* Mixed results, even using pigs for people
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* Scientists are searching for ways to help a damaged central nervous system heal some of its own wounds. One approach has been to transplant, or graft, tissue from a still-developing foetal animal brain (aborted foetuses) into the brain of an adult animal (person)
* Mixed results, even using pigs for people
TRANSPLANTS
89
REGROWING NEURONS
* The most promising source of new neurons now appears to be an individual’s own body, whose cells would not be rejected.
* cell division takes place in the adult central nervous systems of humans
* process of creating new neurons is called neurogenesis
90
* The most promising source of new neurons now appears to be an individual’s own body, whose cells would not be rejected.
* cell division takes place in the adult central nervous systems of humans
* process of creating new neurons is called neurogenesis
REGROWING NEURONS
91
NEURAL STEM CELLS
* special GLIAL cells in the nervous system that are capable of dividing to form new tissue, including new neurons
* stem cells can come from the patient – their bones etc.. still not regular practice tho
92
* special GLIAL cells in the nervous system that are capable of dividing to form new tissue, including new neurons
* stem cells can come from the patient – their bones etc.. still not regular practice tho
NEURAL STEM CELLS
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PROMOTING NEURAL PLASTICITY
• Special mental and physical exercise programs appear useful in ‘rewiring’ the brain
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• Special mental and physical exercise programs appear useful in ‘rewiring’ the brain
PROMOTING NEURAL PLASTICITY
95
HUMAN DEVELOPMENT & THE CHANGING BRAIN
* as we reach adulthood, we develop more brainpower with less brain
* the brain retains its neural plasticity, rewiring itself to form new connections and to eliminate connections too
* the details of the connections depend on experience, including the amount of complexity and stimulation in the environment.
96
* as we reach adulthood, we develop more brainpower with less brain
* the brain retains its neural plasticity, rewiring itself to form new connections and to eliminate connections too
* the details of the connections depend on experience, including the amount of complexity and stimulation in the environment.
HUMAN DEVELOPMENT & THE CHANGING BRAIN
