Download Primary motor cortex

Brain, The Final Frontier
Kiminobu Sugaya, Ph.D.
[email protected]
Http://www.uic.edu/labs/sugaya/
Homeostasis
Response to
Outside and
Inside Environment
I. G eneral comparis on of the b odyХs 2 major controlsys tems
A. Gen eralc omparison
Properties
Anato my
Nervo us Sys tem
Sys tem of neu rona l
pathw ays highly
organized into CNS and
PNS. Each nervous c ell
terminates directlyo n its
target cell.
General functions
Coordinate s the rapid,
precis e responses.
Specifici ty of action
Depends on clos e
physic alass ociation
between th e nervous and
target cell.
Route of chemic al
mess enger
Neurotransmitter is
released into synaptic
cl eft and diffuses a very
short d istanc e to target
cell.
Rapid (millis econds).
Speed of resp onse
Duration of action
Brief (millis econds):
Neurotransmitter is ta ken
back u p to nervous
termina l or i na ctivate by
enzym es wi th in syn aptic
cl eft.
Endocrine Sys tem
In cl udes a number of
structura lly u nre lated
organs, which are wi dely
dispersed throughout
the body. Not
anatomically li nked to
target cells .
Primarilyc ontrols
metabolis m and the
activi ties that require
duration, not speed.
Determine d by presence
of speci fic receptors o n t
target cells . Hormones
bind to receptors i n a
lock-and keyf ashion.
Hormones a re released
into the b lood and
the refore can circ ulate
throughout th e body.
Slow (minute to hours):
Complex mechanism of
action.
Long (minutes to days
or even longer):
ho rmone mayr emain
bound to receptor.
Nervous System
•• Central
Nervous
System
Peripheral
Nervous
system
(CNS)
(PNS)
–
–
–
–
–
–
Brain
Autonomic Nervous System
Spinal Cord
Sympathetic
Olfactory Parasympathetic
Somatic
Optic nerves
Cranial Nerves (3-12)
no
• Almost
Some regeneration
regeneration?????
Afferent Division
Efferent Division
What are the components of
CNS ?
• Neuron
• Glia
Neurons
CELL BODY
Dendrites
Nucleus
Myelin sheath
AXON
Schwann cell
Node of Ranvier
Synaptic terminals
Cells that specialized for transmitted chemical and
electrical signals from one part of the body to another.
Synapses
Impulse
Presynaptic neuron
Vesicle
Transmitters
Synaptic cleft
Postsynaptic
neuron
Receptors
Postsynaptic activity
Classifying Neurons
• Number of axons and
dendrites
• unipolar, bipolar,
multipolar
• Type of connections
• sensory, motor,
interneurons
• Type of
neurotransmitter
• Acetylcholin,
Dopamine
Glia Cells
•
•
•
•
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
Possible Roles of Glia Cells
•
•
•
•
•
•
supporting element
producing myelin
scavengers - removing debris
buffer
guide migration in course of development
help to form special lining in the capillaries - Blood Brain
Barrier (BBB)
Anyone touched human brain?
bumps = gyri
grooves =sulci
(fissures)
Is the brain hard or soft?
The brain is soft.
How it is protected?
QuickTi me™ a nd a
de com press or
are need ed to se e th is p icture.
CSF
QuickTime™ and a
Cinepak decompressor
are needed to see this picture.
Ventricles
QuickTime™ and a
Video decompressor
are needed to see this picture.
QuickTime™ and a
Video decompressor
are needed to see this picture.
Blood-Brain barrier
Cortical layer
I
II
III
Blood vessel
IV
V
Neuron
VI
Mapping the brain function
How much % of the brain are we using?
10%
50%
100%
Frontal
lobe
Parietal lobe
Occipital
lobe
Temporal
lobe
Cerebellum
Primary motor cortex (M1)
Primary motor cortex
(M1)parietal cortex
Posterior
Supplementary
Hip
motor cortex
(SMA)
Trunk
Arm
Hand
Foot
Face
Tongue
Premotor cortex
(PMA)
Larynx
Motor cortex
Somatosensory cortex
Sensory
associative
cortex
Pars
opercularis
Visual
associative
cortex
Broca’s
area
Visual
cortex
Primary
Auditory cortex
Wernicke’s
area
Evidence for localization
• Broca
Wernicke
(1861)
(1876)
ExpressiveAphsia
Receptive
Aphsia
can speak but
can understand
cannot
but cannot
understand
speak
Phenomena in
Environment
Sensory
Stimuli
Excitation in
Sensory Nerve
Integration in
Sensory CNS
Sensation
Perception
Speech
QuickTime™ and a
decompressor
are needed to see this picture.
Quic kTime™ and a
dec ompres sor
are needed to see this picture.
Left
Auditory
cortex
Right
Auditory
cortex
Medial geniculate nucleus
Cochlea
Inferior colliculus
Auditory
nerve fiber
Ipsilateral
Cochlear
nucleus
Superior
Olivary
nucleus
Optic nerve
Optic chiasm
Optic tract
Lateral geniculate nucleus
Optic radiation
Primary visual cortex
What you see, what you get
Line
Retina
Lateral
geniculate
nucleus
Primary
Visual
Cortex (V1)
QuickTime™ and a
GIF decompressor
are needed to see this picture.
QuickTime™ and a
GIF decompressor
are needed to see this picture.
QuickTime™ and a
GIF decompressor
are needed to see this picture.
QuickTime™ and a
GIF dec ompres sor
are needed to s ee this pic ture.
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Processing of sound
QuickTime™ and a
Video decompressor
are needed to see this picture.
QuickTime™ and a
Video decompressor
are needed to see this picture.
Hippocampus
Amygdala
QuickTime™ and a
Animation decompressor
are needed to see this picture.
Coordination and control of voluntary movement.
Nerve pathway of cerebral hemispheres.
Auditory and Visual reflex centers.
Cranial Nerves:
CN III - Oculomotor (Related to eye movement), [motor].
CN IV - Trochlear (Superior oblique muscle of the eye which rotates the eye
down and out), [motor].
Respiratory Center.
Cranial Nerves:
CN V - Trigeminal (Skin of face, tongue, teeth; muscle of mastication), [motor
and sensory].
CN VI - Abducens (Lateral rectus muscle of eye which rotates eye outward),
[motor].
CN VII - Facial (Muscles of expression), [motor and sensory].
CN VIII - Acoustic (Internal auditory passage), [sensory].
Crossing of motor tracts.
Cardiac Center.
Respiratory Center.
Vasomotor (nerves having muscular control of the blood
vessel walls) Centerﾊ
Centers for cough, gag, swallow, and vomit.
Cranial Nerves:
*
CN IX - Glossopharyneal (Muscles and mucous membranes of
pharynx, the constricted openings from the mouth and the oral pharynx and the
posterior third of tongue.), [mixed].
*
CN X - Vagus (Pharynx, larynx, heart, lungs, stomach), [mixed].
*
CN XI - Accessory (Rotation of the head and shoulder), [motor].
*
CN XII - Hypoglossal (Intrinsic muscles of the tongue), [motor].
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Positron Emission Tomography
The PET scan on the left shows two areas of the brain (red and yellow) that become particularly active
when volunteers read words on a video screen: the primary visual cortex and an additional part of the
visual system, both in the back of the left hemisphere.
Other brain regions become especially active when subjects hear words through ear-phones, as seen in
the PET scan on the right.
To create these images, researchers gave volunteers injections of radioactive water and then placed
them, head first, into a doughnut-shaped PET scanner. Since brain activity involves an increase in
blood flow, more blood and radioactive water streamed into the areas of the volunteers' brains that
were most active while they saw or heard words.
fMRI
Very mild activity (blue to red areas) is recorded in certain regions of a volunteer's brain as he hears a
series of sharp but meaningless clicks (see the white box on the left of the first picture.)
When he listened to instrumental music, the same region of the man's brain became much more active
(orange to yellow areas), as shown in the white box on the left of the second picture. But in addition,
several new areas of his brain were activated. This increase in activity reflected the richer meaning of
the sounds.
Magnetoencephalography (MEG)
and MRI
Electroencephalography (EEG)
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Brain, The Final Frontier
Kiminobu Sugaya, Ph.D.
[email protected]
Http://www.uic.edu/labs/sugaya/