Atrial diverticula in severe hydrocephalus.

Massive ventricular dilatation causes stretching and dehiscence of the fornix with formation of unilateral or bilateral pial pulsion diverticula of the inferior medial wall of the atrium. Enlargement of the pial pouch creates a dramatic subarachnoid cyst that may herniate downward through the incisura into the lateral mesencephalic, precentral cerebellar, and superior vermian cisterns where it displaces the brain stem, vermis, and fourth ventricle. Lateral ventricular diverticula may be identified and distinguished from the dilated fourth ventricle and dilated suprapineal recess, with which they are so commonly confused, when all of the following signs are apparent on computed tomography (CT): (1) marked unilateral or bilateral atrial dilatation; (2) focal dehiscence of the medial atrial wall; (3) ipsilateral shortening of the tentorial band in axial section; (4) focal defect in the tentorial band in coronal section; (5) draping of the medial atrial wall over the free margin of tentorium, with continuity of cerebrospinal fluid density around the edge of tentorium in axial and/or coronal sections; (6) bowing of the crus (or crura) of fornix; (7) separation of fornix from splenium, with visualization of the hernia ostium; (8) asymmetrical position of the choroid plexi, which attach to and define the lateral borders of the fornices; (9) contralateral displacement of the internal cerebral veins; and (10) septa separating diverticulum from third ventricle

A double constriction micropipette for the quantitative injection of tracer substance.

A glass, double constriction injector micropipette ('micropet') has been designed to overcome problems associated with commercial microliter syringes. These problems include: inconsistent volume delivery, inability to view tracer during filling or injection, and the relatively large size of the needle supplied. 'Micropets' of different volumes are easily made from inexpensive, commercially available Drummond 100 microliter glass tubes (bores) fitted with teflon plungers.

Functional anatomy of the cerebral cortex by computed tomography.

The authors describe the morphological characteristics that allow recognition of the individual computed tomography slice and determine its sequence in the series. In addition, each slices is "assembled" by defining the different cortical gyri, sulci, and cortical functional areas (based on Brodmann's maps). This work lays the foundation for correlative studies of location of lesions and the clinical picture.

Synaptic fine structure and the termination of corticospinal fibers in the lateral basal region of the cat spinal cord.

The lateral basal region (LBR) of the spinal cord gray matter (Rexed's laminae IV-VII) by physiologic and anatomic criteria is the major terminal zone for the corticospinal (CS) tract in the cat. The neurons in this area are medium-sized with abundant spines on their dendrites. Axon terminals on the dendrites and somata of these neurons form synapses easily classified as asymmetric with spheroid vesicles and symmetric with flattened vesicles.

Fine structure of the rubrospinal terminals in the cervical cord of the cat.

Rubrospinal fibers in cat do not terminate on anterior motor horn cells in the spinal cord but on the interneurons, mostly in the lateral portion of Rexed's lamina of V-VII, the so-called Lateral Basal Region. The ultrastructure of rubrospinal terminals at the cervical cord level (C8) was investigated in 8 adult cats with partial or complete stereotaxic lesions of the red nuclei. Animals were sacrificed from 1 to 7 days after the lesions were made and the earliest forms of degeneration found were infrequent dense preterminal axon changes and clumping and coalescing of synaptic vesicles in the terminals.

Intracranial bleeding associated with urokinase therapy for acute ischemic hemispheral stroke.

Four patients undergoing urokinase infusion therapy for acute occlusive cerebrovascular disease had intracerebral hemorrhage in the ischemic hemisphere. Three patients died during the acute phase of their illness and an autopsy was performed on two. The pathogenesis of cerebral bleeding in these case reports is discussed.

Lysergic acid diethylamide: effects on the developing mouse lens.

High doses (5 x 10-(6) gram) of LSD-25 given to Swiss-Webster females on gestation days 6, 7, 8, or 9 caused a high incidence of anterior subcapsular lens abnormalities. Accompanying this, the lens epithelium was often hyperplastic, and the lens bow was widened posteriorly in a fashion similar to cataracts induced by x-radiation. Confirmation of this effect of LSD-25 was obtained by a (duplicate) experiment 1 year after the observations reported.