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Neuronal correlates of material discrimination in the first somatosensory cortex (SI) of the conscious monkey
$167 NEURONAL (SI)
CORRELATES
YOSHIAKI
IWAMURA,
Department In the contact piece were
not
thus
we
activated interpreted
materials. with
and quick
contact
of the
t o the
themas
a piece
with,
latter
was
sufficiently
in t h e s e
neurons
activated
hand with
brush
hairs.
two additional
neurons which
of the
monkey's
responses
in
fluffiness
fingers
or b a r k ,
these
latter
a n d we
any par%
suggested
c a u s e d by the
the
same
by the c o n t a c t of the m o n k e y ' s
two c a t e g o r i e s
subtle
of a c t i v e
and solid ob]ecns
Conversely
inhibited
and
of the
also that
This observation hairs
neurons
or r e l a t e d
contact
We n o t i c e d
inter-
three
or bark,
of b r u s h e s
with hard
neurons.
were
s u c h as a
Another
sandpaper
of b r u s h
by the
of t h e n e u r o n s
at t h e v e r y m o m e h t
vigorously.
hand with
these
Three
stationary
effective.
The contact
activated
The contact
of
with
light
by the m o v e m e n t
activity
did not evoke
of s a n d p a p e r
to the
Tokyo
preferentially
of t h e m a t e r i a l s .
neurons,
SAKAMOTO*,
Ota-ku,
or r e l a t e d m a t e r i a l s
or r u b b i n g
of t h e e x p e r i m e n t e r ' s
were
activated
of t o i l e t p a p e r .
roughness
responding
these
hairs
piece
the background
skin
SOMA'TOSENSORY C O R T E X
and MASAHIRO
Omori-Nishi,
found neurons
inhibited
hairs.
IN T H E F I R S T
HIKOSAKA*
Med.,
hand with brush
these materials
neurons
we
by the contact
evoked responses these
SI,
Sch.
by rubbing with
To a c t i v a t e
movements
OKIHIDE
Univ.
or a c r i n k l e d
t h e m as r e s p o n d i n g
were
that
monkey
fur,
activated
TANAKA*, Toho
of the m o n k e y ' s
also
touch
MICHIO
conscious
DISCRIMINATION
MONKEY
of P h y s i o l . ,
of r a b b i t
preted
hand
OF M A T E R I A L
OF T H E C O N S C I O U S
of
stimulus
with brushes own hairy
neurons.
CORTICAL AND THALAMIC PROJECTIONS TO THE FIFTH SOMATIC SENSORY CORTEX
AKIO MORI*, KIMISATO NAITO*, TAMIKO SEKI*, KOKO KAGAYA*, NOBUHITO MATSUUP#~* and RHYUJI SUMINO. Department o f Physiology, School o f D e n t i s t r y , Nihon U n i v e r s i t y , I - 8 - 1 3 Kandasurugadai, Chiyoda-ku, Tokyo I01, Japan. We have reported (Mori e t a l . Abstr. 15, 1985) t h a t a new and complete somatic sensory area in cat c o r t e x was found in the medial bank o f the a n t e r i o r suprasylvian sulcus (ASSS). Cells with r e c e p t i v e f i e l d s on the face formed the r o s t r a l aspects of the medial bank o f the ASSS, which is the SV r e p r e s e n t a t i o n . The t a i l and hindlimb areas are s i t u a t e d in the caudal aspects o f the ASSS. The trunk area was located in the medial bank o f the ASSS, between t h e f o r e - and hindlimb regions. The face area was located in the most r o s t r a l region in the medial bank o f the ASSS. We have designated t h i s area as the F i f t h Somatic Sensory Cortex (SV). In the present study we examined proj e c t i o n s from the d i f f e r e n t c o r t i c a l areas and the thalamus to the SV using HRP as a t r a c e r . Under halothane anesthesia, the a n t e r i o r e c t o s y l v i a n ~ r u s (AESG), and the a n t e r i o r suprasylvian gyrus were exposed and a chamber was i n s t a l l e d ober the s k u l l . The experiments were c a r r i e d out on a d u l t cats w i t h a sedative dose o f Ketamine (2mg/Kg). A s i n g l e microelectrode was inserted through a chamber i n t o SV. The spikes were monitored on the o s c i l l o s c o p e and also fed i n t o a speaker through a window d i s c r i m i n a t o r . The s i t e s o f p e n e t r a t i o n were recorded on photographic p r i n t s o f the cort i c a l surface taken through a d i s s e c t i n g microscope. A f t e r t h a t , HRP was i n j e c t e d at the s i t e where the SV neuron was a c t i v i t e d by using natural somesthetic s t i m u l a t i o n . When HRP i n ~ e c t i o n was done in the face region o f the SV, labeled c e l l s were located i p s i l a t e r a l l y in the primary somatic sensory area ( S I ) , the secondary somatic sensory area ( S l I ) , the t h i r d somatic sensory area ( S i l l ) , the f o r t h somatic sensory area (SIV) and the motor c o r t e x (MCx), and the SI and SlV o f the contral a t e r a l c o r t e x . In a d d i t i o n , HRP-labeled c e l l s were obtained in the VPM and Pom. When HRP i n j e c t i o n was done i n t o the hindlimb and trunk regions o f the SV, labeled c e l l s were located i p s i l a t e r a l l y in the SI, S l l , SIV and MCx, and S I , S l l and SV of the c o n t r a l a t e r a l c o r t e x . In a d d i t i o n , HRP-labeled c e l l s were obtained in the VL, CL, VPL, Pom and Pol. The e x t e n t o f these interconnections suggests t h a t SV receives m u l t i p l e sensory i n f o r m a t i o n and may function to i n t e g r a t e these inputs.
CORRELATES
YOSHIAKI
IWAMURA,
Department In the contact piece were
not
thus
we
activated interpreted
materials. with
and quick
contact
of the
t o the
themas
a piece
with,
latter
was
sufficiently
in t h e s e
neurons
activated
hand with
brush
hairs.
two additional
neurons which
of the
monkey's
responses
in
fluffiness
fingers
or b a r k ,
these
latter
a n d we
any par%
suggested
c a u s e d by the
the
same
by the c o n t a c t of the m o n k e y ' s
two c a t e g o r i e s
subtle
of a c t i v e
and solid ob]ecns
Conversely
inhibited
and
of the
also that
This observation hairs
neurons
or r e l a t e d
contact
We n o t i c e d
inter-
three
or bark,
of b r u s h e s
with hard
neurons.
were
s u c h as a
Another
sandpaper
of b r u s h
by the
of t h e n e u r o n s
at t h e v e r y m o m e h t
vigorously.
hand with
these
Three
stationary
effective.
The contact
activated
The contact
of
with
light
by the m o v e m e n t
activity
did not evoke
of s a n d p a p e r
to the
Tokyo
preferentially
of t h e m a t e r i a l s .
neurons,
SAKAMOTO*,
Ota-ku,
or r e l a t e d m a t e r i a l s
or r u b b i n g
of t h e e x p e r i m e n t e r ' s
were
activated
of t o i l e t p a p e r .
roughness
responding
these
hairs
piece
the background
skin
SOMA'TOSENSORY C O R T E X
and MASAHIRO
Omori-Nishi,
found neurons
inhibited
hairs.
IN T H E F I R S T
HIKOSAKA*
Med.,
hand with brush
these materials
neurons
we
by the contact
evoked responses these
SI,
Sch.
by rubbing with
To a c t i v a t e
movements
OKIHIDE
Univ.
or a c r i n k l e d
t h e m as r e s p o n d i n g
were
that
monkey
fur,
activated
TANAKA*, Toho
of the m o n k e y ' s
also
touch
MICHIO
conscious
DISCRIMINATION
MONKEY
of P h y s i o l . ,
of r a b b i t
preted
hand
OF M A T E R I A L
OF T H E C O N S C I O U S
of
stimulus
with brushes own hairy
neurons.
CORTICAL AND THALAMIC PROJECTIONS TO THE FIFTH SOMATIC SENSORY CORTEX
AKIO MORI*, KIMISATO NAITO*, TAMIKO SEKI*, KOKO KAGAYA*, NOBUHITO MATSUUP#~* and RHYUJI SUMINO. Department o f Physiology, School o f D e n t i s t r y , Nihon U n i v e r s i t y , I - 8 - 1 3 Kandasurugadai, Chiyoda-ku, Tokyo I01, Japan. We have reported (Mori e t a l . Abstr. 15, 1985) t h a t a new and complete somatic sensory area in cat c o r t e x was found in the medial bank o f the a n t e r i o r suprasylvian sulcus (ASSS). Cells with r e c e p t i v e f i e l d s on the face formed the r o s t r a l aspects of the medial bank o f the ASSS, which is the SV r e p r e s e n t a t i o n . The t a i l and hindlimb areas are s i t u a t e d in the caudal aspects o f the ASSS. The trunk area was located in the medial bank o f the ASSS, between t h e f o r e - and hindlimb regions. The face area was located in the most r o s t r a l region in the medial bank o f the ASSS. We have designated t h i s area as the F i f t h Somatic Sensory Cortex (SV). In the present study we examined proj e c t i o n s from the d i f f e r e n t c o r t i c a l areas and the thalamus to the SV using HRP as a t r a c e r . Under halothane anesthesia, the a n t e r i o r e c t o s y l v i a n ~ r u s (AESG), and the a n t e r i o r suprasylvian gyrus were exposed and a chamber was i n s t a l l e d ober the s k u l l . The experiments were c a r r i e d out on a d u l t cats w i t h a sedative dose o f Ketamine (2mg/Kg). A s i n g l e microelectrode was inserted through a chamber i n t o SV. The spikes were monitored on the o s c i l l o s c o p e and also fed i n t o a speaker through a window d i s c r i m i n a t o r . The s i t e s o f p e n e t r a t i o n were recorded on photographic p r i n t s o f the cort i c a l surface taken through a d i s s e c t i n g microscope. A f t e r t h a t , HRP was i n j e c t e d at the s i t e where the SV neuron was a c t i v i t e d by using natural somesthetic s t i m u l a t i o n . When HRP i n ~ e c t i o n was done in the face region o f the SV, labeled c e l l s were located i p s i l a t e r a l l y in the primary somatic sensory area ( S I ) , the secondary somatic sensory area ( S l I ) , the t h i r d somatic sensory area ( S i l l ) , the f o r t h somatic sensory area (SIV) and the motor c o r t e x (MCx), and the SI and SlV o f the contral a t e r a l c o r t e x . In a d d i t i o n , HRP-labeled c e l l s were obtained in the VPM and Pom. When HRP i n j e c t i o n was done i n t o the hindlimb and trunk regions o f the SV, labeled c e l l s were located i p s i l a t e r a l l y in the SI, S l l , SIV and MCx, and S I , S l l and SV of the c o n t r a l a t e r a l c o r t e x . In a d d i t i o n , HRP-labeled c e l l s were obtained in the VL, CL, VPL, Pom and Pol. The e x t e n t o f these interconnections suggests t h a t SV receives m u l t i p l e sensory i n f o r m a t i o n and may function to i n t e g r a t e these inputs.