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Medial occipital projections to the nucleus of Darkschewitsch of rhesus monkey.

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Medial Occipital Projections to the Nucleus of
Darkschewitsch of Rhesus Monkey
Neurological U n i t , Boston State Hospital, Boston, Massachusetts 02124
Projection from medial occipital cortex (area OB) to the nucleus
of Darkschewitsch is demonstrated in six Macaca mulatta hemispheres by the
technique of Fink and Heimer. Degeneration was present as well in the lateral
pons, nucleus lateralis dorsalis, nucleus lateralis posterior, lateral pulvinar and
nucleus parafascicularis. Centrum medianum, dorsal lateral geniculate body
and interstitial nucleus of Cajal were spared.
Lateral cortical projections to the mesencephalon are topographically organized
within tectal and tegmental structures. In
both mammals and sub-mammals cortical
efferents follow an orderly projection pattern to mesencephalic tegmentum (Kuypers and Lawrence, '67; Martin, '68). Thus,
granular frontal cortex projects to median
tegmentum, posterior frontal and anterior
parietal areas project to paramedian tegmentum, and occipital and posterior temporal cortex project to dorsolateral tegmentum. The topography of projections
from medial cortical areas is less well
known. Lesions of cingulate gyrus (Showers, '59) and superomedial frontal cortex
produce greater degeneration in the median
tegmentum than lesions farther laterally
(Kuypers and Lawrence, '67). Connections
between medial posterior frontal cortex
and the nucleus of Darkschewitsch have
been demonstrated (Black and Myers, '62).
Whether similar connections exist with the
medial wall of the occipital lobe is uncertain, Convexal occipital lesions (Spatz,
Tigges and Tigges, '70) as well as occipital
lobectomy (Black and Myers, '62; Myers,
'63) have been reported without mention
of connections to the nucleus of Darkschewitsch. It is known however that the upper
lip of calcarine fissure sends fibers not only
to the central grey and tegmentum of the
mesencephalon but also to field H2 (Mettler, '35) which is known to constitute an
important input to this nucleus (Woodbourne, Crosby and McCotter, '46). The
present study was undertaken to assess the
relationship between medial occipital corANAT. REC., 178: 667-670.
tex and the nucleus of Darkschewitsch.
Radio frequency lesions were placed in
medial OB cortex of six hemispheres of
Macaca mulatta. In all but one a small
amount of underlying white matter was included in the lesion (fig. 1). Following
fourteen days survival animals were sacrificed with an overdose of barbiturate anesthesia. The brains were perfused in situ
with saline and formol saline. Following
fixation and embedding, specimens were
sectioned in the stereotaxic coronal plane
at 35
and stained by the cresyl violet
technique and by the method of Fink and
Heimer (Heimer, '70). As expected, terminal degeneration was present in the lateral
pons; the more dorsal the cortical lesion,
the farther lateral was the pontine degeneration. In thalamus, degenerating fibers
were distributed to nucleus lateralis dorsalis, nucleus lateralis posterior, the lateral
pulvinar and the nucleus parafascicularis.
The nucleus centrum medianum was unaffected, as was the dorsal lateral geniculate
body. In contrast dense degeneration was
evident in the ventral lateral geniculate
nucleus. In all specimens striking degeneration was evident in the region of the
nucleus of Darkschewitsch (fig. 2). It was
present as well in the adjacent pericentral
grey and the pretectal nucleus. The interstitial nucleus of Cajal was conspicuously
spared. It is of interest that this nucleus,
which is known to project to the oculoReceived Mav. 29.
. '73. Accepted SePt. 11, '73.
1 Supported in part by PHS grant
R01 NS04131-11.
Dr. Wright is currently at the Department of
Neurosurgery, University of Vermont Medical School,
Burlington, Vermont.
Fig. 1 Diagrammatic representation of cortical lesions in sjx Macaca mulatta hemispheres. Degeneration illustrated i n plate 1 occurred homolateral to the lesion illustrated in column 5.
Cortical projections to the red nucleus and
motor complex (Carpenter, Harbison and
brain stem i n the Rhesus monkey. Brain Res.,
peter, ' 7 0 ) showed no terminal degenera4; 151-188.
medial Occipital lesions, Martin, G. F., Jr. 1968 The pattern of neocorwhile the nucleus of Dakschewitsch, altical projections to the mesencephalon. Brain
leged to inhibit extraocular muscles (SzenRes., 11: 593-610.
tagothai and Schab, ' 5 6 ) , shows profuse Mettler, F. A. 1935 Corticofugal fiber connecprojections. The current study adds antions of the cortex of Macaca mulatta: the occipital region. J. Comp. Neur., 61: 221-255.
Of Origin
Of fibers proMeyers, R. E. 1963 Cortical projections to mid.
jecting to the nucleus of Darkschewitsch.
brain i n monkey. Anat. Rec., 145; 339 (abLITERATURE CITED
Black, P., and R. E. Myers 1962 Connections of
occipital lobe i n the monkey. Anat. Rec., 142:
216 (abstract).
Carpenter, N. B., J. W. Harbison and P. Peter
1970 Accessory oculomotor nuclei in the monkey: Projections and effects of discrete lesions.
J. Comp. Neur., 140: 131-154.
Heimer, L. 1970 Selective silver-impregnation
of degenerating axoplasm. I n : Contemporary
Research Methods in Neuroanatomy. W. J. H.
Nauta and S. 0. E. Ebbesson, eds. Springer
Verlag, New York, pp. 106-132.
Kuypers, H. G. J. M., and D. G. Lawrence 1967
Showers, M. J. C. 1959 The cingulate gyrus:
Additional motor area and cortical autonomic
regulation. J. Comp. Neur., 112: 231-302.
Spatz, M. B., J. Tigges and M. Tigges 1970 Subcortical projections, cortical associations and
some intrinsic interlaminar connections of the
striate cortex in the squirrel monkey (Saimiri).
J. Comp. Neur., 140; 155-174.
Szenthgothai, J., and R. Schab 1956 A midbrain
inhibitory mechanism of oculomotor activity.
Acta Physiol. Acad. Sci. Hung., 9: 89-98.
Woodbourne, R. T., E. C. Crosby and R. E.
McCotter 1946 The mammalian midbrain and
isthmus regions. J. Comp. Neur., 85: 67-93.
Degeneration i n the region of the nucleus of Darkschewitsch. Above:
Topography of area i n low power Nissl stained section adjacent to the
sections illustrated below in Fink-Heimer technique. The nucleus of
Darkschewitsch and interstitial nucleus of Cajal are indicated. FinkHeimer preparations reveal conspicuous degeneration i n the nucleus
of Darkschewitsch (left column) at medium and high magnification,
i n contrast to the adjacent interstitial nucleus of Cajal (right column).
S. Wright, Jr., J. Hilsz and S. Locke
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darkschewitsch, occipital, monkey, rhesus, projections, media, nucleus
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