motor roots innervate in brachial muscles in the anterior
Most of these cells, after receiving impulses from primary
.
sensory nuclei, send their axons to somatic motor nuclei_
)r(egnl :rnve innervates widely over the body in the same way as Furthermore, in the specialized ones among these elements,
in other animals, namely, in taste buds of the mouth, lateral
extremely large Mauthner cells are observed in the medial
line organs, tactile organs of the skin, and visceral sense
part Of the same level (*Hemiramphus sajorz‘, *Gadus
organs and the motor nerves innervate in branchial muscles
macrocephalus, *1Wystm‘ophz‘s porphyreus).
These cells, after
and other numerous visceral organs.
having received various kinds of sensory impulses through
The motor nuclei of VII, IX and X which are the centers of
numerous
dendrites, participate chiey in the movement of
:
visceral motor function, in general, form the visceral motor
the tail through a thick axon which is situated in a portion
column at dorso-lateral of fasciculus Iongitudinalis medialis
of fasciculus Iongitudinalis medialis.
As already stated, in
as
in the case with the nucleus ambiguus of higher animals.
teleosts, nerves homologous to the llth and 12th nerves of
There are exceptions in motor nucleus of VII, however, it
higher animals are absent.
ln many cases, the 15t spinal
seems that the nucleus ambiguus of the sh does not form
nerves
are
deformed and the dorsal roots of which are
a
lateral column separately as is observed in higher animals.
dierently located, while below the 2nd spinal nerves the
The medulla oblongata is united with the optio tectum
nerves
are
arranged in the dorsal and ventral position.
As
mainly by tractus tecto-bulbaris, with cerebellum by tractus
already stated, the arrangement of the spinal nerves of the
cerebelIo—spinalis and tractus cerebello-motorius as well as
cervical cord greatly varies according to the shape of
it is connected with the acoustico—lateralis area by tractus
the skulls and the musculature in the cervical trunk of
octave-motorius.
And, in sh in which the visceral sensory
respective sh.
ln some sh, several lobes are observed in
lobe is well-developed, the secondary gustatory tract coming
dorsal area covering caudal portion of the medulla and
out from the said lobe reaches the mesencephalon
cervical cord.
The formation of these lobes is most
(*Upeneus be1zsasi, *Chaeturichthys hexanema, *Gadus
remarkable in sh, the n rays of which are transformed
macrocephalus).
Main bers coming from the
into leg—like appendages (*Chelz‘donichthys kumu, *Lepz‘d0trigla
acoustico-lateralis area form lateral lemniscus and connect
77zz‘croptera).
It is considered that these lobes perform
acoustico-lateralis area with torus semicircularis of the
somatic sensory function which receive bers from the
mesencephalon.
tactile organs of the appendages, and this is due to the
Fasciculus Iongitudinalis medialis originating at the dorsal
enormous
enlargement of the dorsal hom.
thalamus and mesencephalic tegmentum, forms an important
This phenomenon is remarkable in sea robins in which there
ber tract of somatic nature which extends from the medulla
are
six lobes (C. J. Herrick, 1899).
On the outer side of the
oblongata to the spinal cord, and receives principally
cervical cord in some sh, a group of enormously large cells
reticular elements which are present extensively in the
exist dorsally.
These cells were found long ago (Fritsch,
tegmentum and medulla oblongata as well as bers coming
1886) and are called supramedullary ganglion cells (*Fugu
from the acoustico-lateral area.
Fibers of Mauthner cells,
rubripeS, *L0phius Etalon).
Their function has not been
described above, are positioned on the dorsal of fasciculus
determined.
It is regarded by some scientists as being
Iongitudinalis medialis.
The fasciculus Iongitudinalis
proprioceptive, and by others as neurosecretory
Large cells
medialis sends bers to the adjacent somatic motor column.
of this kind are sometimes present even in the inner portion
In sh, the fasciculus Iongitudinalis medialis plays an
of the cord (intramedullary ganglion cells).
They may be
important role in reex action of eye movement and
homologous to large glandular cells observed in the caudal
locomotion.
Generally, reticular elements of sh brain are
portion of the cord in some sh.
best developed at the level of lateral area. Müller cells
?
forming part of the reticular elements are Iarge-sized and
scattered widely from the ventral part of acoustico—lateral
March, 1965
area to the medial and sometimes even to part of the raphe.
TUGE, Hideomi
%
l
ll
12—13
Il
Most of these cells, after receiving impulses from primary
.
sensory nuclei, send their axons to somatic motor nuclei_
)r(egnl :rnve innervates widely over the body in the same way as Furthermore, in the specialized ones among these elements,
in other animals, namely, in taste buds of the mouth, lateral
extremely large Mauthner cells are observed in the medial
line organs, tactile organs of the skin, and visceral sense
part Of the same level (*Hemiramphus sajorz‘, *Gadus
organs and the motor nerves innervate in branchial muscles
macrocephalus, *1Wystm‘ophz‘s porphyreus).
These cells, after
and other numerous visceral organs.
having received various kinds of sensory impulses through
The motor nuclei of VII, IX and X which are the centers of
numerous
dendrites, participate chiey in the movement of
:
visceral motor function, in general, form the visceral motor
the tail through a thick axon which is situated in a portion
column at dorso-lateral of fasciculus Iongitudinalis medialis
of fasciculus Iongitudinalis medialis.
As already stated, in
as
in the case with the nucleus ambiguus of higher animals.
teleosts, nerves homologous to the llth and 12th nerves of
There are exceptions in motor nucleus of VII, however, it
higher animals are absent.
ln many cases, the 15t spinal
seems that the nucleus ambiguus of the sh does not form
nerves
are
deformed and the dorsal roots of which are
a
lateral column separately as is observed in higher animals.
dierently located, while below the 2nd spinal nerves the
The medulla oblongata is united with the optio tectum
nerves
are
arranged in the dorsal and ventral position.
As
mainly by tractus tecto-bulbaris, with cerebellum by tractus
already stated, the arrangement of the spinal nerves of the
cerebelIo—spinalis and tractus cerebello-motorius as well as
cervical cord greatly varies according to the shape of
it is connected with the acoustico—lateralis area by tractus
the skulls and the musculature in the cervical trunk of
octave-motorius.
And, in sh in which the visceral sensory
respective sh.
ln some sh, several lobes are observed in
lobe is well-developed, the secondary gustatory tract coming
dorsal area covering caudal portion of the medulla and
out from the said lobe reaches the mesencephalon
cervical cord.
The formation of these lobes is most
(*Upeneus be1zsasi, *Chaeturichthys hexanema, *Gadus
remarkable in sh, the n rays of which are transformed
macrocephalus).
Main bers coming from the
into leg—like appendages (*Chelz‘donichthys kumu, *Lepz‘d0trigla
acoustico-lateralis area form lateral lemniscus and connect
77zz‘croptera).
It is considered that these lobes perform
acoustico-lateralis area with torus semicircularis of the
somatic sensory function which receive bers from the
mesencephalon.
tactile organs of the appendages, and this is due to the
Fasciculus Iongitudinalis medialis originating at the dorsal
enormous
enlargement of the dorsal hom.
thalamus and mesencephalic tegmentum, forms an important
This phenomenon is remarkable in sea robins in which there
ber tract of somatic nature which extends from the medulla
are
six lobes (C. J. Herrick, 1899).
On the outer side of the
oblongata to the spinal cord, and receives principally
cervical cord in some sh, a group of enormously large cells
reticular elements which are present extensively in the
exist dorsally.
These cells were found long ago (Fritsch,
tegmentum and medulla oblongata as well as bers coming
1886) and are called supramedullary ganglion cells (*Fugu
from the acoustico-lateral area.
Fibers of Mauthner cells,
rubripeS, *L0phius Etalon).
Their function has not been
described above, are positioned on the dorsal of fasciculus
determined.
It is regarded by some scientists as being
Iongitudinalis medialis.
The fasciculus Iongitudinalis
proprioceptive, and by others as neurosecretory
Large cells
medialis sends bers to the adjacent somatic motor column.
of this kind are sometimes present even in the inner portion
In sh, the fasciculus Iongitudinalis medialis plays an
of the cord (intramedullary ganglion cells).
They may be
important role in reex action of eye movement and
homologous to large glandular cells observed in the caudal
locomotion.
Generally, reticular elements of sh brain are
portion of the cord in some sh.
best developed at the level of lateral area. Müller cells
?
forming part of the reticular elements are Iarge-sized and
scattered widely from the ventral part of acoustico—lateral
March, 1965
area to the medial and sometimes even to part of the raphe.
TUGE, Hideomi
%
l
ll
12—13
Il