Beyin ve Bilinç

Transkript

Beyin ve Bilinç

Ses
Işık
Sinirbilime giriş...
Bilinçle ilişkisine de bir bakış...
Tuesday, October 26, 2010
1
e
ach revolution
ous paradigms
d view
PowerPoint Presentation
Temel kaynaklar
for
Physiology of Behavior
Tenth Edition
by
Neil R. Carlson
Prepared by Robert Flint, The College of Saint Rose
This multimedia product and its contents are protected under copyright law. The following are prohibited by law:
• any public performance or display, including transmission of any image over a network;
• preparation of any derivative work, including extraction, in whole or in part, of any images;
•any rental lease, or lending of the program.
Copyright © Allyn & Bacon 2010
2
Nerede kalmıştık
3
Nerede kalmıştık
•
„Siz“, neşeleriniz, üzüntüleriniz,
anılarınız, ihtiraslarınız, benlik ve özgür
irade duygularınız ile, aslında çok sayıda
nöron ve bunlarla ilişkili moleküllerin bir
arada davranışından ibaretsiniz (Crick,
1994)
3
Nerede kalmıştık
•
•
1994)
„Crickʻin varsayımını şaşır%cı kılan, ne
kadar şaşır%cı olmadığıdır“ (Noë, 2009)
3
Nerede kalmıştık
•
•
•
1994)
„Crickʻin varsayımını şaşır%cı kılan, ne
kadar şaşır%cı olmadığıdır“ (Noë, 2009)
Şimdi biraz geriye saralım
3
Konu başlıkları
4
Konu başlıkları
• Neden sinir sistemi?
4
Konu başlıkları
• Nöronlar ve işlevleri
4
Konu başlıkları
• İşlevsel parsellenme
4
Konu başlıkları
• Sinir sisteminin yapısı
4
Konu başlıkları
• Sinir sisteminin yapısı
• Eee?
4
Neden sinir sistemi?
5
• Dalai Lama’ya dert anlatmak
5
• Sinir sistemi - hareket bağlantısı
5
• Hareketten davranışa
5
• Amipe bakalım
5
• Amipe bakalım
5
• Amipe bakalım
5
Amip
6
Amip
6
Amip
• Duyu ve hareket yüzeyleri aynı hücrede
6
Amip
• Duyu ve hareket yüzeyleri aynı hücrede
• Gene de davranışsal tasvir oluyor
6
Ve sinir sistemi
7
Ve sinir sistemi
• Hidrada sinir hücresi, duyu ve hareket yüzeyleri
arasında katmanı görüyoruz
7
Ve sinir sistemi
•
Sinir sistemi duyu ve hareket yüzeylerini
birleştirici role sahip
7
Ve sinir sistemi
•
Sinir sistemi duyu ve hareket yüzeylerini
birleştirici role sahip
7
Figure 2-4 Neurons can be classified as
unipolar, bipolar, or multipolar according to the number of processes that
originate from the cell body.
Toplarsak....
A Unipolar cell
B Bipolar cell
A. Unipolar cells have a single process,
Periphe
with different segments serving as recepto s k n
tive surfaces or releasing terminals.
muscle
Unipolar cells are characteristic of the invertebrate nervous system.
B. Bipolar cells have two processes that
are functionally specialized: the dendrite
Snge
logy of Behavior
-Cell
body
proces
carries information to the cell, and the
axon transmits information to other cells.
Central
Axon
C. Certain neurons that carry sensory information, such as information about
touch or stretch, to the spinal cord belong
Invertebrate neuron
Bipolar cell of retina
Ganglion cell of dorsal root
to a subclass of bipolar cells designated
pseudo-unipolar.As such cells develop,
classified as as
the two processes of the embryonic bipoD Three types of multipolar cells
olar accord- lar cell become fused and emerge from
the A
cellUnipolar
body as acell
single process. This outsses that
B Bipolar cell
growth
then
splits
into
two
processes,
y.
both of which function as axons, one goe process, ing to peripheral skin or muscle, the other
Peripheral axon
ing as recep- going to the central spinal cord.
t o s k n and
D. Multipolar cells have an axon and many
minals.
muscle
dendrites.
They
are
the
most
common
tic of the intype of neuron in the mammalian nervous
system. Three examples illustrate the
cesses that large diversity of these cells. Spinal motor
neurons (left) innervate skeletal muscle
he dendrite fibers.
S n g e bifurcated
Pyramidal cells (middle) have a
-Cell
body
process
, and the
roughly triangular cell body; dendrites
o other cells. emerge from both the apex (the apical
Ax
Central
dendrite) and the base (the basal denAxon
sensory in- drites). Pyramidal cells are found in the
n about
hippocampus and throughout the cerebral
l cord belong cortex. Purkinje cells of the cerebellum
Motor
Purknje cell of cereb
Tuesday, October 26,(right)
2010 Invertebrate
8
Pyramidal
of
are characterized
ex- cell
neuronby the rich andBipolar
of neuron
retinaof
Ganglion
cell ofcell
dorsal
root
1-
1-
Toplarsak....
A Unipolar cell
B Bipolar cell
Periphe
muscle
Snge
logy of Behavior
-Cell
body
proces
Central
Axon
Invertebrate neuron
classified as as
the A
cellUnipolar
body as acell
B Bipolar cell
growth
then
splits
into
two
processes,
y.
Peripheral axon
t o s k n and
minals.
muscle
dendrites.
They
are
the
most
common
he dendrite fibers.
S n g e bifurcated
-Cell
body
process
, and the
Ax
Central
n about
Motor
2010 Invertebrate
8
Pyramidal
of
are characterized
ex- cell
of neuron
retinaof
Ganglion
cell ofcell
dorsal
root
• Duysal hücreler, hareket hücreleri, ve aralarında 1onları “birleştiren” sinir hücreleri (nöronlar)
1-
Toplarsak....
A Unipolar cell
B Bipolar cell
Periphe
muscle
Snge
logy of Behavior
-Cell
body
proces
Central
Axon
Invertebrate neuron
classified as as
the A
cellUnipolar
body as acell
B Bipolar cell
growth
then
splits
into
two
processes,
y.
Peripheral axon
t o s k n and
minals.
muscle
dendrites.
They
are
the
most
common
he dendrite fibers.
S n g e bifurcated
-Cell
body
process
, and the
Ax
Central
n about
Motor
2010 Invertebrate
8
Pyramidal
of
are characterized
ex- cell
of neuron
retinaof
Ganglion
cell ofcell
dorsal
root
• Nöron doktrini: Bireysel nöronlar, sinir
sisteminin iletişim birimleridir. (Cajal)
1-
Toplarsak....
A Unipolar cell
B Bipolar cell
Periphe
muscle
Snge
logy of Behavior
-Cell
body
proces
Central
Axon
Invertebrate neuron
classified as as
the A
cellUnipolar
body as acell
B Bipolar cell
growth
then
splits
into
two
processes,
y.
Peripheral axon
t o s k n and
minals.
muscle
dendrites.
They
are
the
most
common
he dendrite fibers.
S n g e bifurcated
-Cell
body
process
, and the
Ax
Central
n about
Motor
2010 Invertebrate
8
Pyramidal
of
are characterized
ex- cell
of neuron
retinaof
Ganglion
cell ofcell
dorsal
root
• Nöron doktrini: Bireysel nöronlar, sinir
sisteminin iletişim birimleridir. (Cajal)
1-
Nöronlar konuşurken...
• İki nöronun “konuştuğu” noktaya sinaps denir
• “Sinaptik benlik” hipotezi (Changeux)
9
İletişimin iki yüzü
10
• Elektriksel
10
• Elektriksel
10
• Elektriksel
• Kimyasal
10
• Elektriksel
• Kimyasal
Chapter 10 / Overview of Synaptic Transmission
Act~onpotenta n
nerve termnal
opens Ca2+channels
ca2+entry causes
vesicle fuson and
transmtter release
183
Receptor-channels open,
Nat enters the postsynaptic
cell and v e s c e s recycle
Presynaptic
acton potential
Excitatory
postsynaptic
@
e
e'
@
potential
Nai
Na+
NaT
cell
10
İletişim iki nörona özel değil
Eksi- nöral
etkileşimler
Artı+ nöral
etkileşimler
Eşiğe
ulaşıldığında
nöron ateş ediyor
Artılar eksileri
götürüyor, ateşleme
yok
11
Kurbağa ve sinek
12
Kurbağa ve sinek
• Sinek yakalamak gibi bir davranışı açıklamak için
beyinde bunu gerçekleştiren sinirsel devreleri bul
12
Kurbağa ve sinek
•
Sinirsel devreler bir program gibi davranırlar.
Nöron sineği tanır çünkü programının parçasıdır.
12
Kurbağa ve sinek
•
•
Nöral seçicilik
12
Kurbağa ve sinek
•
•
Nöral seçicilik
12
Kurbağa ve sinek
•
•
Nöral seçicilik
12
Kurbağa ve sinek
•
•
Nöral seçicilik
12
Kısaca görsel seçicilik
• V1
13
Kısaca görsel seçicilik
• IT
14
İşlevsel parselleme
grew, it purportedly caused the overlying skull to bulge,
creating a pattern of bumps and ridges on the skull that
indicated which brain regions were most developed
(Figure 1-1). Rather than looking within the brain, Gall
sought to establish an anatomical basis for describing
character traits by correlating the personality of individuals with the bumps on their skulls. His psychology,
based on the distribution of bumps on the outside of the
head, became known as phrenology.
In the late 1820s Gall's ideas were subjected to experimental analysis by the French physiologist Pierre
Flourens. By systematically removing Gall's functional
centers from the brains of experimental animals,
Flourens attempted to isolate the contributions of each
"cerebral organ" to behavior. From these experiments
he concluded that specific brain regions were not responsible for specific behaviors, but that all brain regions, especially the cerebral hemispheres of the forebrain, participated in every mental operation. Any part
of the cerebral hemisphere, he proposed, was able to
perform all the functions of the hemisphere. Injury to a
specific area of the cerebral hemisphere would therefore
affect all higher functions equally.
In 1823 Flourens wrote: "All perceptions, all volitions occupy the same seat in these (cerebral) organs; the
faculty of perceiving, ofNerede
conceiving, of willing merely
constitutes therefore a faculty which is essentially
one." The rapid acceptance of this belief (later called the
aggregate-field view of the brain) was based only partly on
Flourens's experimental work. It also represented a cultural reaction against the reductionist
view that the huNe
man mind has a biological basis, the notion that there
was no soul, that all mental processes could be reduced
to actions within different regions in the brain!
The aggregate-field view was first seriously challenged in the mid-nineteenth century by the British neurologist J. Hughlings Jackson. In his studies of focal
epilepsy, a disease characterized by convulsions that be-
• Erken 19. yüzyıl, Franz Joseph
•
Gall, frenoloji
Miskin & Ungerleider (1982)
Figure 1-1 According to the nineteenth-century doctrine of
phrenology, complex traits such as combativeness, spirituality, hope, and conscientiousness are controlled by specific areas in the brain, which expand as the traits develop.
This enlargement of local areas of the brain was thought to produce characteristic bumps and ridges on the overlying skull,
from which an individual's character could be determined. This
map, taken from a drawing of the early 1800s, purports to
show 35 intellectual and emotional faculties in distinct areas of
the skull and the cerebral cortex underneath.
analysis of how the brain produces language. Before we
consider the relevant clinical and anatomical studies
concerned with the localization of language, let us
briefly look at the overall structure of the brain. (The
anatomical organization of the nervous system is described in detail in Chapter 17.)
15
Parselleme
•
•
Brodmann mikroskopik gözlemlerle parselliyor
Diğer yöntemler:
'L
Anatomik bağlantılar
C
Topografik haritalar
Hücre tepki özellikleri
Alansal tepki özellikleri
Kaba anatomi
328
•
•
•
•
•
Part IV / The Neural Basis of Cognition
Prefrontal
association
cortex
Primary
motor
cortex
Parietal
association
cortex
Primary
visual
cortex
l1
IVC
I
Figure 17-7 The prominence o f particular cell layers of the cerebral cortex varies throughout the cortex.
Sensory cortices, such as the primary
visual cortex, tend to have very prominent internal granule cell layers. Motor
cortices, such as the primary motor
cortex, have a very meager layer IV but
prominent output layers, such as layer
V. These differences led Brodmann and
others working at the turn of the century to divide the brain into various cytoarchitectonic regions. The subdivision by Brodmann (1909) seen in the
b o t t o m half of this illustration is a classic analysis but was based on a single
human brain! (From Martin 1996.)
Lateral
16
Toplarsak...
17
Toplarsak...
1. “Beynin tüm tarihi tek bir temel nokta ile
alakalıdır: Hareket ilintili duysal-motorsal
korelasyonlar”
17
Toplarsak...
1. “Beynin tüm tarihi tek bir temel nokta ile
alakalıdır: Hareket ilintili duysal-motorsal
korelasyonlar”
2. Nöron sinir sisteminin işlevsel birimidir, çünkü
duysal-motorsal korelasyonlar nöronların
bağlantıları sayesinde mümkündür.
17
Sinirbilimin iki önfikri/inancı
Object representations
Same but different
Identify
will sub
frames
visual w
Contex
Figure 1 | Some of the intricate object relations that are accommodated in the brain.
Objects that look very similar can be represented and recognized as different objects, whereas
objects that look very different can be recognized as the same basic-level objects.
We seem
in our e
percept
based fa
previou
highligh
A ty
contextu
compar
violated
familiar
sistent
recogni
expecte
finding
18
recognit
• Beynin devre ve programları birlikte bütün
akılsal ve bilişsel olayların kaynağıdır
Same but different
Identify
will sub
frames
visual w
Contex
We seem
in our e
percept
based fa
previou
highligh
A ty
contextu
compar
violated
familiar
sistent
recogni
expecte
finding
18
recognit
• Beynin devre ve programları birlikte bütün
•
akılsal ve bilişsel olayların kaynağıdır
Bu program veya devreler iyi işlemektedir,
çünkü hayvanın içinde yaşadığı dünyayı iyi bir
şekilde temsil etmektedir.
Same but different
Identify
will sub
frames
visual w
Contex
We seem
in our e
percept
based fa
previou
highligh
A ty
contextu
compar
violated
familiar
sistent
recogni
expecte
finding
18
recognit
Sinir sisteminin yapısı
• Şu anda periferi ile uğraşmıyoruz
19
Beyin-kan bariyeri
• Kandaki çoğu madde, vücudun geri kalanının
tersine, beyine ulaşamaz
on of Cerebrospinal Fluid: Blood-Brain Barrier, Brain Edema, and Hydrocephalus
Beyin hariç vücuttaki
damar
General capillary
1289
Beyinde damar
Brain capillary
Kana madde giriş çıkışına izin veren
boşluklar
interceiular
Beyin hariç vücuttaki damar
Fen
Beyinde damar
20
Nereden başlasak?
• Ventrikül sistemi
• Descartes’a kadar ruh
•
buralarda
Beyin-omurilik sıvısı
21
Genel bakış
Önbeyin Ortabeyin
Arkabeyin
Serebral
yarıküre
Beyin
kökü
Beyincik
Omurilik
22
Önbeyin - telensefelon
• Korteks
• Geniş çaplı hasarlar uzun
Beyaz
madde
Serebral korteks
(gri madde)
23
Korteks bölgeleri
24
Korteks ve bilinç
• Hiyerarşide yukarıda
• Ne? geçişi
• Uzun mesafeli uyum
25
Önbeyin - telensefelon
• Limbik sistem
• Amygdala - duygular
(korku)
• Hippokampus - hafıza
yazımı
• Ampül hafıza
Beyincik
Omurilik
26
Önbeyin - diyensefelon
• Hipotalamus: Tür-tipik
•
•
•
davranışlar
Talamus / İstasyon
Hareketsel
Algısal
Korteksle karşılıklı
Beyin kökünün üstü
•
•
27
Chapter 38 / Voluntary Movement
•
•
•
Supplementary
761
Primary
motor cortex
davranışlar
Talamus / İstasyon
Hareketsel
Algısal
•
•
Figure 38-5
cerebellum
caudal portions of the ventrolateral nucleus; VPLo=oral portion
of the ventral posterolateral nucleus; X=nucleus X.
tactile stimuli applied to specific regions of the digits
and palms. These so-called transcortical circuits are
discussed later. Second, the primary motor cortex receives inputs from posterior parietal area 5. Posterior
parietal areas 5 and 7 are involved in integrating
multiple sensory modalities for motor planning (Figure
38-4A).
pears to have a unique pattern of cortical and subcortical input. Thus there are many cortico-subcortical loops,
each one making a different contribution to a motor behavior (Chapter 43).
The Somatotopic Organization of the Motor Cortex
27
Chapter 38 / Voluntary Movement
•
•
•
Supplementary
761
Primary
motor cortex
davranışlar
Talamus / İstasyon
Hareketsel
Algısal
•
•
Figure 38-5
cerebellum
caudal portions of the ventrolateral nucleus; VPLo=oral portion
of the ventral posterolateral nucleus; X=nucleus X.
23
tactile stimuli applied to specific regions of the digits
and palms. These so-called transcortical circuits are
discussed later. Second, the primary motor cortex receives inputs from posterior parietal area 5. Posterior
parietal areas 5 and 7 are involved in integrating
multiple sensory modalities for motor planning (Figure
38-4A).
pears to have a unique pattern of cortical and subcortical input. Thus there are many cortico-subcortical loops,
Copyright
& Bacon
2010
each one
making©a Allyn
different
contribution
to a motor behavior (Chapter 43).
The Somatotopic Organization of the Motor Cortex
27
not and the effect of the anaes
determined whether patients wo
somatosensory stimulation or no
to that found in the cortex at loss of consciousness until
5 minute after the patients were intubated. The middle graph, from a representative subject, shows (in red)
Talamus ve bilinç
•
Power spectrums
Raw EEG Tracings
SITE OF ACTION: CORTEX?
EEG (F3–C3)
ESCoG (p0–p3)
EEG (F3–C3)
12
ESCoG (p0–p3)
Baseline
Anestezi durumu, bitkisel
hayat örnekleri, ve
BOX 10.1
uykudaki
osilasyonlar
talamokortikalUNCONSCIOUSNESS
sistemlerin
NICOTINIC REVERSAL
OF ANAESTHETIC-INDUCED
bilinç için önemli olduğunuambulate,
gösteriyor.
as if immune to the consciousness suppressThe sequential pictures are from a representative video
ing action of anaesthesia (Figure 10.5E). This dramatic rethat shows an anaesthetized unconscious rat lying on
versal
of the unconsciousness
component of anaesthesia
Ama
rolü daha
öncül
olabilir
its back (Figure
10.5A).korteksin
Shortly after a microinfusion
of
lasts only a few minutes, a time consistent with the pharLoss of
consciousness
After
intubation
5 minute after
intubation
1
0
1
2
3
4
sec
0
15
30 Hz 0
15
30 Hz
Frequency
Dimensional Dimensional
activation
activation
How
to
Cortical (F3–C3)
28
20
12 Hz
4
reverse
anaesthetic-induced
Dimensional activation
(C)
10
8
6
4
macology of nicotine. The Thalamic
arousal
response generally did
(p0–p3)
28
10
not occur8if the microinfusion of nicotine did not involve
20
Hz
6
12
the CM thalamus
(the grey shaded region of the lower
4
4
(D)
(E)
16
20
24
26
30
0
4
8
12
rat brain anatomy
pictures).
The
histology
schematics
Time (minute)
show
the locations
of infusions and
theirvs.corresponding
Conscious
vs. unconscious
Movers
non-movers
behavioural responses.
The reversal of unconsciousness
Movers
Conscious
14
14
Non-movers
is a site-specific effectUnconscious
that depends upon changing
the
12
12
activity
of neurons within the intralaminar
CM thalamus.
Full arousal
No effect
10
10
Abbreviations:
CM: central medial8 thalamus, Dent: den8
tate gyrus
of the hippocampus, IMD:
intermediodorsal
6
6
nucleus,
MHb: medial habenular 4nucleus, nRt: thalamic
4
2
2
reticular
nucleus,
Re:reuniens thalamic
nucleus,
PVP:
ESCoG
ESCoG
EEG
EEG
Cortex
Thalamus
Cortex
Thalamus venparaventricular
thalamic nucleus (posterior),
Va/Vl:
tral anterior and ventral lateral thalamic nucleus. Rat atlas
FIGURE 10.6 Chicken or egg? Who is off first, the cortex or the thalamus?
image from Paxino’s and Watson [73] (with permission).
Dimensional activation
FIGURE
Tuesday,
October 26,10.5
2010
4
sec
Loss of Consciousness
nicotine into its central medial thalamus the rat begins
to arouse (Figure 10.5B–D). He turns over and begins to
(B)
3
Time
•
(A)
2
28
Beyin kökü
• Çıkan sinirler omuriliktekilerden farklı değil, yüz
Chapter 44 / Brain Stem, Reflexive Behavior, a n d the Cranial Nerves
877
ve kafa kasları ile içorgan çalışmalarını etkiliyorlar
Lateral genicuate body
lnfer~orcolliculus
44-2 A lateral v i e w o f t h e b r a i n
ustrating t h e location o f t h e craves. This view clearly shows the
nce of the trochlear (IV) nerve
e dorsal surface of the midbrain
facial (Vll) and vestibulocochlear
rves from the cerebellopontine
Trochlear nerve (IV)
Basis pedunculi
Cerebellar peduncles,
Superior
Pons
Abducens
Mddle
Inferior
Vestibulocochlear
nerve (VIII)
Glossopharyngeal (1x1
and vagus nerves (X)
glossal nerve (XII)
Spinal accessory
nerve (XI)
29
Beyin kökü ve bilinç
e spinal cord that modulate autonomic reflexes and pain
nsation. The A6 cell group, the locus ceuuleus, sits dorsally
d laterally in the periaqueductal and periventricular gray
atter (Figure 45-2), The locus ceruleus, which maintains vignce and responsiveness to unexpected environmental stim, has extensive projections to the cerebral cortex and cerellum, as well as descending projections to the brain stem
d spinal cord.
Adrenergic Cell Groups
Some neurons in the two columns of cells in the medulla identified as catecholaminergic were later found to synthesize epiPart VII
Arousal,
Emotion,
and extenBehavioral Homeostasis
892
nephrine. The C1
adrenergic
cell/group
forms
a rostral
sion from the A1 column in the rostral ventrolateral medulla
(Figure 45-1).
neurons project to the 'pinal
particularly to the sympathetic preganglionic column, where they
Box 45-1 The Major Modulatory Systems of the Brain (continued)
Chapter 45 / Brain Stem Modulation of Sensation, Movement, and Consciousness
893
• Talamus altı beyin kökü yapıları, yani ordaki
AGIlocus ceruleus
are thought to provide tonic excitatory input to vasomotor
Chapter 45 / Brain
Modulation of Sensation, Movement, and Consciousness
8
Dopaminergic
CellStem
Groups
neurons. Other C1 neurons terminate in the hypothalamus,
The dopaminergic cell groups in the midbrain and forebrain
where they modulate cardiovascular and endocrine responses.
were originally numbered as if they were a rostral continuaThe C2 adrenergic neurons, which are a component of the nution of the noradrenergic system because identification was
cleus of the solitary tract, contribute to the ascending pathway to
based
on histofluorescence, which does not distinguish
the parabrachial nucleus (Figure 45-I), which is thought to transdopamine
from norepinephrine very well.
Serotonergic Cell Groupsmit gastrointestinal information. The C3 adrenergic group is
The
AS-A10
cell groups include the substantia nigra pars
located near the midline at the rostral end of the medulla.
cornpacta
and
the
adjacent areas of the midbrain tegmentum
Most serotonergic neurons areNeurons
located along
the
midline
of
the
groups
provide
a major
mixed in with thethe
C3 spinal
and C1 cord
that
modulate
autonomic reflexes and pain
Adrenergic Cell Groups
45-3).
They
send the major ascending dopaminergic in(Figure
(from
French
forsensation.
seam).
brain stem in the vapke nucleiinput
to vapkd
the locus
ceruleus,
but most The
of the
A6cells
cellcontributing
group, the locus ceuuleus, sits dorsally
puts to the telencephalon, including
the nigrostriatal
pathway
Some neurons
in the two
columns of cells in the medulla ide
Raphe neurons in the B1-B3 cell
groups
along
of
to this
pathway
arethe
notmidline
adrenergic.
and laterally
in the periaqueductal and periventricular gray
tified
as
catecholaminergic
were later found to synthesize ep
the caudal medulla (Figure 45-4) send descending projections
matter (Figure 45-2), The locus ceruleus, which maintains vignephrine.
The
C1
adrenergic
cell group forms a rostral exte
to the motor and autonomic systems in the spinal cord.
The
ilance and responsiveness to unexpected environmental stimsion
from
the
A1
column
in
the
rostral ventrolateral medul
raphe magnus nucleus (B4) at the level of the rostra1 medulla
uli, has extensive projections to the cerebral cortex and cere(Figure
45-1).
neurons
project
to the 'pinal
pa
projects to the spinal dorsal horn and is thought to modulate
bellum, as wellAas descending projectionsCaudate
to the brain stem
Corpus ticularly to the sympathetic preganglionic column, where th
the perception of pain. The serotonergic groups in theand
pons
spinal cord.
nukleuslar, korteksin de takalumsun da bir çok
yerine modüle edici sinyaller gönderir.
Adrenerjik
Dopaminerjik
e striatum and is thought to be involved in
responses. Mesocortical and mesolimbic
hways arising from the A10 group innervate
mporal cortices and the limbic structures of
n. These pathways have been implicated in
and memory storage. The A l l and A13 cell
rsal hypothalamus, send major descending
hways to the spinal cord. These pathways
gulate sympathetic preganglionic neurons.
cell groups, along the wall of the third venents of the tuberoinfundibular hypothalamic
ystem. Dopaminergic neurons are also found
stem (A15 cells in the olfactory tubercle and
ry bulb) and in the retina (A17 cells).
and midbrain (B5-B9) include the pontine, dorsal, and median
raphe nuclei and project to virtually the whole of the forebrain.
Serotonergic pathways play important regulatory roles in
hypothalamic cardiovascular and thermoregulatory control
Figure 45-3 Dopaminergic neurons
and modulate the responsiveness
of brain
cortical
neurons.
in the
stem
and hypothalamus.
AGIlocus ceruleus
A. Dopaminergic neurons in the substantia nigra (A9 group) and the adjacent retrorubral field (A8 group) and
ventral tegmental area (A10 group) pro-
Serotonerjik
gure 45-2 Noradrenergic neurons in the pons.
Noradrenergic neurons are spread across the pons in three
ore or less distinct groups: the locus ceruleus (A6 group) in
e periaqueductal gray matter, the A7 group more ventrolaterly, and the A5 group along the ventrolateral margin of the
ontine tegmentum.
. The A5 and A7 neurons mainly innervate the brain stem and
pinal cord, whereas the locus ceruleus provides a major asending output to the thalamus and cerebral cortex as well as
~xteria~
capsule
tonergic neurons along the midline of the
ons in the B1-3 groups, corresponding to the
October
26, 2010
pheTuesday,
pallidus, and
raphe obscurus
nuclei in the
vide a major ascending pathway that
terminates in the striatum, the frontotemporal cortex, and the limbic sysdescending projections
to the brain
stem, cerebellum,
tem, including
the central
nucleus of and
~yriform
amygdala;
A 0and
= anterior
olfactory
nucleus;
spinal cord. A = the
amygdala
the lateral
septum.
cortex
Cerebellum
BS = brain
stem;B.CHypothalamic
= cingulate bundle;
CC = corpus
callosum;
dopaminergic
neurons
CT = central tegmental
tract;
CTX
=
cerebral
cortex;
DT
in the A1 Iand A13 cell groups, in the =
dorsal tegmental zona
bundle;
EC =provide
externallong
capsule;
F = fornix; H =
incerta,
descending
hypothalamus; Hpathways
F = hippocampal
formation;
LC
to the autonomic areas=oflocus
ceruleus; OB = olfactory
= pretectal
nuclei; RF =
the lowerbulb;
brainPT
stem
and the spinal
reticular formation;
S =Neurons
septum;
= A12
tectum;
in Tthe
and Th
A14= thalamus.
cord.
groups, located along the wall of the
Olfactory
third ventricle, are involved with enbulb
(continued)
docrine control. Some of them release
dopamine as a prolactin release inhibiting factor in the hypophysial portal circulation.
'Lateral
parabrachial
~eitral
~ntbrhinal ~ i c l e u s
nucleus
cortex
accumbens
iamygdala)
Noradrenerjik
Medial forebrain
bundle
-Serotonergic
innervation
raphe, and dorsal raphe nuclei, project to the upper brain stem,
Figure 45-2 Noradrenergic neurons in the pons.
hypothalamus, thalamus, and cerebral cortex. CD = caudate
A.ThNoradrenergic
neurons are spread across the pons in three
nucleus; HF = hippocampal formation; H = hypothalamus;
=
descending projections to the brain stem, cerebellum, and
spinal cord. A = amygdala; A 0 = anterior olfactory nucleus;
30
Bilinç kaybı
Chapter 45 / Brain Stem Mo
p
e
e
Figure 45-7 Injuries to the ascending arousal system, from
the rostra1 pons through the thalamus and hypothalamus
(purple area), can cause loss of consciousness.
bra1 cortex and thalamus increase wakefulness and vigilance, as well as the responsiveness of cortical and thalamic neurons to sensory stimuli, a state known as
arousal. These pathways are joined by ascending cholinergic inputs from the pedunculopontine and laterodorsal tegmental nuclei and by other cell groups from the
d
v
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31 a
Bilinç kaybı
•
Beyin kökü olma hali ile
ilişkili
p
e
e
d
v
u
o
s
W
m
a
o
in
b
w
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i
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31 a
Bilinç kaybı
•
•
ilişkili
Asıl mesele talamokortikal
gibi görünüyor
p
e
e
d
v
u
o
s
W
m
a
o
in
b
w
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i
m
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31 a
Bilinç kaybı
•
•
•
ilişkili
gibi görünüyor
Gerikalan bölgeler bir
uyanıklılık ve tahrik
edilebilirlik hali veriyor
p
e
e
d
v
u
o
s
W
m
a
o
in
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t
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u
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31 a
Bilinç kaybı
•
•
•
•
ilişkili
gibi görünüyor
Gerikalan bölgeler bir
uyanıklılık ve tahrik
edilebilirlik hali veriyor
Bitkisel hayattaki hastalarda
normal beyin kökü
aktivitesi, uyanık görünüş
p
e
e
d
v
u
o
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W
m
a
o
in
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31 a
Omurilik
• Hepsini göstermiş olmak için
• Gri ve beyaz iç ve dış farkı
32
Derken...
Serebral
yarıküre
• Korteks ve talamus şu
•
ana dek en ilginçleri
Ama temel sorulara
yaklaşmadık bile....
Beyin
kökü
Beyincik
Omurilik
33
Ses
Işık
34
“Eğer ‘kişi-lik’ bireysel bir kişi olmanın nitelik
ya da durumuna tekabül ediyorsa, ‘beyin-lik’ de
bir beyin olmanın nitelik ya da durumuna verilen
ad olabilir. Bu ontolojik nitelik ‘serebral özneyi’
tanımlar, ki bu özne, hiç olmazsa endüstrileşmiş
ve fazlasıyla tıbbileşmiş toplumlarda, kendisine
20. yüzyıl ortalarından beri birçok toplumsal atıf
edinmiştir”. (Fernando Vidal, 2009, “Brainhood,
anthropological figure of modernity”, History of
the Human Sciences)
35

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