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A variety of experimental evidence has implicated the mesencephalic raphe complex of nuclei and the locus coeruleus in the regulation of slow-wave sleep and REM sleep, respectively, and in the maintenance of diencephalic and telencephalic levels of serotonin and norepinephrine. The present study defines further the critical loci subserving brain stem control of fore-brain monoamine levels and electrographic indicators of these two states of sleep. After baseline sleep profiles were determined, lesions were placed in the dorsal and ventral tegmentum of the medbrain in cats. Following these lesions, fluorometric assay of various brain regions revealed widespread depletion of serotonin and norepinephrine although few differences in the pattern of regional reduction of monoamines were noted between the cats with dorsal and ventral tegmental lesions. However, comparison of sleep-waking profiles of the animals taken 2 wk after the lesion with profiles taken before yielded no consistent alterations in waking, slow-wave sleep of REM sleep. These results indicate no clear-cut correlation between regional levels of brain amines and sleep-waking profiles.

Temporal bone findings in a 75-year-old man with a 34-year history of unilateral Meniere syndrome showed severe subepithelial fibrosis of the intermediate endolymphatic sac, bilaterally. The nonhydropic side showed narrow patency of the utriculoendolymphatic valve together with questionable "fullness" of the saccule duct and slight bulging of the adjacent free wall of the saccule. The vein of the vestibular aqueduct, on the same side, drained spontaneously into a large vascular channel within bone marrow, in its course toward the posterior fossa, before joining with the tissue of the vestibular aqueduct. This was not present on the hydropic, Meniere side. The collateral drainage of the vein of the vestibular aqueduct may have acted as a spontaneous shunt, compensating the fluid mechanics to an extent where incipient hydrops, only, was present.

An experiment was performed to determine the origin of the projection from the hippocampus to the septal area in the subrimate mammalian nervous system. Lesions were made by aspiration or by radio frequency in 4 gerbils, 17 rats, 8 rabbits, and 7 cats. Survival times varied from 2–5 days. Tissues were stained principally with the Fink Heimer I method for identification of degenerating axons and their terminals. Following lesions destroying any one or more of the fields of the dorsal hippocampus of the gerbil, rat, rabbit, or cat, terminal degeneration was observed only in the medial septal area, olfactory tubercle, and adjacent portions of the diagonal band. In addition, lesions producing total destruction of all dorsal hippocampal fields also resulted in the presence of terminal degeneration restricted to the medial septal area. In contrast, superficial lesions of field CA1 of the ventral hippocampus produced terminal degeneration in the lateral septal area, nucleus accumbens, olfactory tubercle, and adjacent portions of the diagonal band. Similar findings were also observed following more widespread lesions of the ventral hippocampus which produced damage to other CA fields as well. Superficial lesions of the posterior crus of the hippocampus (i.e., a position midway between dorsal and ventral hippocampus) resulted in terminal degeneration localized to an intermediolateral region of the septum. Combined lesions of the dorsal hippocampus and fimbria produced widespread terminal degeneration in both the lateral and medial septum indicating that the axons contained within the fimbria arise only from the ventral hippocampus. Finally, lesions of the medial and lateral segments of the fornix of the cat produced terminal degeneration in the medial and lateral regions of the septum, respectively. These findings, collectively, indicate that the origin of the topographical projection to the medial and lateral septum are the dorsal and ventral hippocampus, respectively. This projection is unrelated to cytoarchitectonic fields within the hippocampus and is also invariant among the species considered in this study.

The relationships of the standard ten-twenty electrode placement system to the infant cerebral cortex were studied in seven cadavers at the time of autopsy. In contradistinction to previous studies, the average location of our central electrode (C 3,4) was over the postcentral gyrus. In addition, our entire temporal line of electrodes (F 7, 8: T 3, 4: T 5, 6) was more inferiorly placed than that of a previous study. The inferior frontal electrode actually lay inferior to the frontal lobe in most instances. Despite meticulous measurement of electrode positions, a discrete but definite variability of anatomic correlation between brains and between hemispheres of the same brain was found for most electrode positions.

The fine structure of the blood vessels of an apparently primary intracerebral malignant lymphoma was compared with those in another malignant lymphoma in a retroperitoneal lymph node. The essential features of the blood vessels in both cases were the same. They resembled the blood vessels found in normal lymph nodes and were both distinctly different from those seen in normal brain. It was concluded that the direction of differentiation of the blood vessels which arise to nourish the neoplastic tissue is determined by the nature of the tumor rather than the vessels from which they originate.

Patients with unilateral removals from the right or left temporal lobes, two amnesic patients with bilateral mesial temporal-lobe damage, and normal control subjects were taught to use visual imagery as an aid in the recall of verbal material. The results showed that, on a paired-associate learning task, patients with left temporal-lobe lesions could partially compensate for their verbal memory defects by using imagery, whereas amnesic patients derived no benefit from such a mnemonic. Patients with right temporal lobectomy performed similarly to normal subjects.

Five free-ranging rhesus monkeys underwent resections of prefrontal cortex anterior to the frontal eyefields. Four others sustained bilateral ablations of the cingulate gyrus. Four of the 5 prefrontal animals failed to rejoin their social group on release and remained solitary until their deaths. The one animal to rejoin the social group was a yearling. All prefrontal animals except the yearling exhibited increased levels of aimless pacing activity. Three of the 4 animals with bilateral cingulate lesions returned to the social group and appeared largely unchanged by the extensive cerebral lesions. The fourth animal, a 5-year-old male, remained solitary until his early death 2–3 days later. However, abandonment of social group and adoption of a temporary solitary state occurs frequently among males of this age group on Cayo Santiago. Ten control animals trapped from the group all returned to the social group and appeared unaffected. The present results support the hypothesis that the prefrontal and the anterior temporal cortical regions both contribute importantly to the control and regulation of social behavior in the subhuman primate.

Publisher Summary This chapter discusses problems related to interpretation in the chemical pathology of schizophrenia. Researchers believe that all of the changes noted in schizophrenic brains must be considered nonspecific or artifactual either on the basis of inadequate criteria for normative ranges of histological appearances, or as the result of age changes or other somatic influences of the many kinds prevalent in a chronic schizophrenic population, or to inadequate standardization of fixation and histological preparative procedures. The first and the most important problem is the nosology of mental disease, the assignments of subjects to class and subclass representing publicly verifiable and operationally or ostensivly definable ensembles. This is absolutely essential for establishment of meaningful correlations between psychopathology and biological phenomena. The second problem (already alluded to) is that of biological variability that, in the case of the nervous system, is a two-dimensional problem. Intraspecies ranges of normative data values, particularly for metabolic indices, are very great and especially so in an outbred species.

Five monkeys were individually trained to emit a relatively prolonged call of specified loudness in order to obtain a preferred food. At the completion of training each animal gave the required call in response to a signal cue light and withheld calls during periods in which no cue light was present. Sequential bilateral removal of the homolog of Broca's area, transitional parieto-occipital cortex, and temporal association cortex in 3 monkeys had no influence on performance of the discriminative call. There was no change in sound spectral properties of the call as a result of surgery. Bilateral removal of anterior cingulate/subcallosal gyrus in the remaining two monkeys was accompanied by loss of phonatory performance. Postoperative calls given by each of these animals in the test situation were weak and infrequent. The data indicate that control over learned, discriminative phonation in monkeys is not mediated by neorcortical regions homologous to human ‘speech’ areas.

A case of TGA is presented in which the clinical and EEG data suggest that in certain cases discharges from mesial temporal lobe structures may be important in the pathophysiology of this syndrome. The possibility of a postictal state was also discussed. Sleep recordings with nasopharyngeal electrodes are recommended in evaluating this syndrome.

Over a 30-month period, subtemporal subdural hematoma was diagnosed arteriographically and verified surgically in 14 patients. It is not a rare lesion and usually occurs in the anterior portion of the middle fossa. When carotid angiography is performed, the submentovertical projection is added to standard views of trauma patients with a suspected middle fossa mass. Routine projections will not demonstrate most subtemporal subdural hematomas, because of the anatomical features of the fossa. When intratemporal injury and subtemporal subdural hematoma occur together, arteriography facilitates accurate diagnosis of both lesions as well as an understanding of their relative proportions.

Clinical EEGs from six patients are studied to show the usefulness of computer calculated ratios in lateralizing focal abnormalities. Ratios related to electrode recording position were calculated, using all channels of the normal clinical EEG recording. This study of six patients was part of a larger study of which these six were the only ones to show focal lesions. The results suggest that these objective measures from the EEG should be useful to cliniciana as an aid in the diagnosis of focal lesions.

Association fibers, degenerating as a result of laminar heat lesions in area 18 of Saimiri, were traced to their respective cortical terminal sites. A strong intrinsic fiber system connected the supragranular cell layers with the underlying layer V of area 18. In addition, the supragranular layers of area 18 projected ipsilaterally to area 17, the territory of area 19 and area MT in the posterior bank of the superior temporal sulcus. Sparse fibers were traced to the cortex in the intraparietal sulcus and to area 8. The projection upon area 17 was strictly topographical; the termination of these fibers was restricted to layer I of area 17. The projection upon area 18 also showed signs of a topographical organization, though less distinct. The evidence for the existence of Brodmann's classic area 19 or its possible replacement as suggested by Allman and coworkers is discussed. Callosal fibers terminated in a topographically organized manner in a strip of cortex posterior in area 18, i.e., the OBg of von Bonin, and in a strip of cortex probably in anterior area 18. A sparse projection connected area 18 with the contralateral area MT.

Previous studies have shown that treeshrews without striate cortex can easily discriminate between two simple patterns presented simultaneously. It has been suggested that these animals cannot actually ''identify'' patterns without striate cortex, but simply detect differences between two stimuli by scanning. The present study showed that tree shrews with damage to striate cortex, including complete removal, can discriminate horizontal from vertical stripes when presented either simultaneously or successively. This result supports the view that tree shrews do have the capacity to identify patterns in the absence of striate cortex. The present study also showed that tree shrews can perform the same discrimination following damage to the temporal cortex. However, if the lesion included all of the striate cortex plus a large amount of temporal cortex, the animals failed to discriminate the orientation of stripes even when they were displayed simultaneously.

In learning experiments novel and familiar sentences were presented acoustically to human subjects during EEG slow wave sleep. Frequency spectra of parieto-occipital and temporo-occipital EEGs were analyzed 25 sec before and 5–30, 30–55 and 55–80 sec after presentation. Statistical comparisons between spectra were performed, using the distribution means. Three qualities of learning were distinguished in tests after the termination of sleep: “spontaneous recall”, “recognition” and “no recall-no recognition”. The presentation caused EEG activations of different level and durations. The cases of “no recall-no recognition” were associated with the lowest EEG activations. Significantly higher and longer activations were found when learning was successful, indicating a systematic relationship between level of EEG activation after presentation of the material, and quality of learning. Further, for the same quality of learning, significantly higher activations were associated with novel than with familiar learning material. Thus, the EEG pattern which exists after the input of learning material to the brain reflects the brain functional state whose level (as characterized by EEG wave frequency) and duration (in conjunction with the factors: interference and difficulty of the learning task) determines the possibility of later recall.