50
JERALD J. BERNSTEIN
icles, etc. ) are transported from the perikaryon. However, other studies
on transected Mauthner cell axons have shown that a portion of protein
synthesis can be derived from axonal and perhaps glial metabolism
( Edstrom, 1964a,b, 1966).
VI. CEREBELLUM
A. Anatomy
In fish, as in most other vertebrates, the cerebellum is the most
variable structure within the nervous system. In the Mormyrids the
valvula cerebelli is hypertrophied and extends over the dorsal surface of
the telencephalon ( Aronson, 1963; Nieuwenhuys, 1967a; Nieuwenhuys
and Nicholson, 1967). In contrast, in Bdellostoma, a myxinid, the cerebellum is represented by a small commissure which consists of eighth
nerve and lateral line nerve fibers, the octavo-lateralis system (Bone,
1963; Larsell, 1967; Nieuwenhuys, 1967a).
Larsell (1967) demonstrated that in most groups of fishes the cerebellum is comprised of two fundamental divisions, a cortical basal lobe
(vestibulo-lateralis ) which receives vestibular and lateral line nerve
fibers and a more rostrally situated body of the cerebellum (corpus
cerebelli, often convoluted) which receives afferent nerve fibers from the
spinal cord, fifth nerve, optic tectum, as well as other systems. The vestibulo-lateralis lobe in the majority of fishes consists of a small intermediate
portion with occasionally enlarged lateral auricles ( auriculae cerebelli ) .
The auricles are largest in those animals that possess extensive latcral
line systems: Chondrichthyes, Polypteriformes, and Crossopterygi ( Nieuwenhuys, 19674, In the actinopterygians dense neural centers situated
lateral to the corpus cerebelli, the eminentiae grmulares, represent vestibular and lateral line nerve centers. In these fish the cerebellum also
possesses a bilateral rostral subtectal projection, known as the valvula
cerebelli. The developnicnt of this rostral outgrowth is concomitant with
the extensive development of the lateral line.
The structure of the cerebellum appears to be generally similar
throughout the vertebrate kingdom. It is comprised of an internal
stratum albium containing both the afferent axonal inflow from lower
and higher centers and the efferent axonal outflow to lower and higher
neural centers. The next layer is the stratum granulosuni which is an
area of granular cells. This layer is followed by the Purkinje ccll layer.
JERALD J. BERNSTEIN
icles, etc. ) are transported from the perikaryon. However, other studies
on transected Mauthner cell axons have shown that a portion of protein
synthesis can be derived from axonal and perhaps glial metabolism
( Edstrom, 1964a,b, 1966).
VI. CEREBELLUM
A. Anatomy
In fish, as in most other vertebrates, the cerebellum is the most
variable structure within the nervous system. In the Mormyrids the
valvula cerebelli is hypertrophied and extends over the dorsal surface of
the telencephalon ( Aronson, 1963; Nieuwenhuys, 1967a; Nieuwenhuys
and Nicholson, 1967). In contrast, in Bdellostoma, a myxinid, the cerebellum is represented by a small commissure which consists of eighth
nerve and lateral line nerve fibers, the octavo-lateralis system (Bone,
1963; Larsell, 1967; Nieuwenhuys, 1967a).
Larsell (1967) demonstrated that in most groups of fishes the cerebellum is comprised of two fundamental divisions, a cortical basal lobe
(vestibulo-lateralis ) which receives vestibular and lateral line nerve
fibers and a more rostrally situated body of the cerebellum (corpus
cerebelli, often convoluted) which receives afferent nerve fibers from the
spinal cord, fifth nerve, optic tectum, as well as other systems. The vestibulo-lateralis lobe in the majority of fishes consists of a small intermediate
portion with occasionally enlarged lateral auricles ( auriculae cerebelli ) .
The auricles are largest in those animals that possess extensive latcral
line systems: Chondrichthyes, Polypteriformes, and Crossopterygi ( Nieuwenhuys, 19674, In the actinopterygians dense neural centers situated
lateral to the corpus cerebelli, the eminentiae grmulares, represent vestibular and lateral line nerve centers. In these fish the cerebellum also
possesses a bilateral rostral subtectal projection, known as the valvula
cerebelli. The developnicnt of this rostral outgrowth is concomitant with
the extensive development of the lateral line.
The structure of the cerebellum appears to be generally similar
throughout the vertebrate kingdom. It is comprised of an internal
stratum albium containing both the afferent axonal inflow from lower
and higher centers and the efferent axonal outflow to lower and higher
neural centers. The next layer is the stratum granulosuni which is an
area of granular cells. This layer is followed by the Purkinje ccll layer.