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Brain ventricle is one of the biomarkers for detecting neurological disorders. Studying the shape of the ventricles will aid in the diagnosis process of atrophy and other CSF-related neurological disorders, as ventricles are filled with CSF. This paper introduces a spectral analysis algorithm based on wave kernel signature. This shape signature was used for studying the shape of segmented ventricles from the brain images. Based on the shape signature, the study groups were classified as normal subjects and atrophy subjects. The proposed algorithm is simple, effective, automated, and less time consuming. The proposed method performed better than the other methods heat kernel signature, scale invariant heat kernel signature, wave kernel signature, and spectral graph wavelet signature, which were used for validation purpose, by producing 94-95% classification accuracy by classifying normal and atrophy subjects correctly for CT, MR, and OASIS datasets.

Although the central canal is an integral component of the cerebral ventricular system, central canal dilation has not been examined adequately during the progression of subarachnoid hemorrhage-related hydrocephalus (SAH-H). Central canal dilation-associated ependymal cell desquamation or subependymal membrane rupture has been rarely reported. Herein, we try to describe possible mechanisms of central canal dilation "Hydromyelia," developing after SAH. A total of 25 New Zealand hybrid female rabbits were recruited. Five served as controls, and five received sham operations. In the remaining animals (n = 15), 0.5 mL/kg of autologous blood was injected into the cisterna magna twice on 0 and 2nd days. Five of these animals died within a few days. A total of 10 survivor animals decapitated 3 weeks later, and the brains and cervical spinal cords were histologically examined. Central canal volumes, ependymal cell numbers on the canal surfaces, and the Evans' indices of the ventricles were compared. On histological examination, central canal occlusion with desquamated ependymal cells and basement membrane rupture were evident. The mean Evans' index of the brain ventricles was 0.31, the mean central canal volume was 1.054 mm3, and the normal ependymal cell density was 4.210/mm2 in control animals; the respective values were 0.34, 1.287 mm3, and 3.602/mm2 for sham-operated animals, and 0.41, 1.776 mm3, and 2.923/mm2 in the study group. The differences were statistically significant (p < 0.05). Hydromyelia, an ignored complication of SAH-H, features ependymal cell desquamation, subependymal basement membrane destruction, blood cell accumulation on the subependymal cell basement membrane, and increased CSF pressure. Hydromyelia may be a significant complication following SAH.

The ependymal lining of the walls of the human brain third ventricle (3v), fourth ventricle (4v) and aqueductus cerebri (A) was studied. For a better localization of different ependymal areas, they were labelled by periventricular structures that represent a basic and stable part of brain nerve tissue and they are localized most closely to ventricle walls. Labelling of individual ependymal areas of the ventricle walls was composed of the number of a brain ventricle, letters: E – ependyma and abbreviation of a Latin name of the periventricular structure, e.g., the corpus mammillare is “CM“. Labelling of ependyma over the corpus mammillare is” 3vE – CM “Results of labelling of ependymal areas were arranged in the form of tables called “ependymal table “(ET), i.e., ET for 3v; ET for 4v; ET for A. It is believed that labelling of individual ependymal areas according to periventricular structures could be useful for unambiguous labelling of ependyma of the ventricle walls and will help to a mutual comparison of the same types of ependymal areas studied by various authors.

Although the central canal is an integral component of the cerebral ventricular system, central canal dilation has not been examined adequately during the progression of subarachnoid hemorrhage–related hydrocephalus (SAH-H). Central canal dilation–associated ependymal cell desquamation or subependymal membrane rupture has been rarely reported. Herein, we try to describe possible mechanisms of central canal dilation “Hydromyelia,” developing after SAH. A total of 25 New Zealand hybrid female rabbits were recruited. Five served as controls, and five received sham operations. In the remaining animals (n = 15), 0.5 mL/kg of autologous blood was injected into the cisterna magna twice on 0 and 2nd days. Five of these animals died within a few days. A total of 10 survivor animals decapitated 3 weeks later, and the brains and cervical spinal cords were histologically examined. Central canal volumes, ependymal cell numbers on the canal surfaces, and the Evans’ indices of the ventricles were compared. On histological examination, central canal occlusion with desquamated ependymal cells and basement membrane rupture were evident. The mean Evans’ index of the brain ventricles was 0.31, the mean central canal volume was 1.054 mm3, and the normal ependymal cell density was 4.210/mm2 in control animals; the respective values were 0.34, 1.287 mm3, and 3.602/mm2 for sham-operated animals, and 0.41, 1.776 mm3, and 2.923/mm2 in the study group. The differences were statistically significant (p < 0.05). Hydromyelia, an ignored complication of SAH-H, features ependymal cell desquamation, subependymal basement membrane destruction, blood cell accumulation on the subependymal cell basement membrane, and increased CSF pressure. Hydromyelia may be a significant complication following SAH.

The accumulation of cerebrospinal fluid (CSF) in brain ventricles and subarachnoid space is known as hydrocephalus. Hydrocephalus is a result of disturbances in the secretion or absorption process of CSF. A hydrocephalus shunt is an effective method for the treatment of hydrocephalus. In this paper, at first, the procedures of secretion, circulation, and absorption of CSF are studied and subsequently, the mathematical relations governing the pressures in different interacting compartments of the brain are considered. A mechanical-electrical model is suggested based on the brain physiology and blood circulation. In the proposed model, hydrocephalus is modeled with an incremental resistance (Ro) and hydrocephalus shunt, which is a low resistance path to drain the accumulated CSF in the brain ventricles, is modeled with a resistance in series with a diode. At the end, the simulation results are shown. The simulation results can be used to predict the shunt efficiency in reducing CSF pressure and before a real shunt implementation surgery is carried out in a patient’s body.

Cerebrospinal fluid (CSF) flow in the brain ventricles is critical for brain development. Altered CSF flow dynamics have been implicated in congenital hydrocephalus (CH) characterized by the potentially lethal expansion of cerebral ventricles if not treated. CH is the most common neurosurgical indication in children effecting 1 per 1000 infants. Current treatment modalities are limited to antiquated brain surgery techniques, mostly because of our poor understanding of the CH pathophysiology. We lack model systems where the interplay between ependymal cilia, embryonic CSF flow dynamics and brain development can be analyzed in depth. This is in part due to the poor accessibility of the vertebrate ventricular system to in vivo investigation. Here, we show that the genetically tractable frog Xenopus tropicalis, paired with optical coherence tomography imaging, provides new insights into CSF flow dynamics and role of ciliary dysfunction in hydrocephalus pathogenesis. We can visualize CSF flow within the multi-chambered ventricular system and detect multiple distinct polarized CSF flow fields. Using CRISPR/Cas9 gene editing, we modeled human L1CAM and CRB2 mediated aqueductal stenosis. We propose that our high-throughput platform can prove invaluable for testing candidate human CH genes to understand CH pathophysiology.

CDKL3 has an important role in regulating cell growth and/or differentiation, and its inactivation is recently reported to be related to non-syndromic mild mental retardation (MR). MR is a common neurological disorder, predominantly characterized by impaired cognitive function. Though genetic factors play a very important role in the pathogenesis of MR, to date, only few genes linked to MR have been characterized and understood very well. Here, we investigated the role of the CDKL3 in the proliferation of cells surrounding the brain ventricle, and the results showed down-regulating CDKL3 by the method of RNAi in the cells surrounding the brain ventricle of the mouse embryo at E15 may inhibit their proliferation. As our previous study had shown that Cdkl3 mRNA expression is developmentally regulated in the central nervous system, peaking during late embryonic and early postnatal stages which are the key stages of neurite formation and maturation, furtherly, the present findings indicated that CDKL3 may be involved in proliferation of cells surrounding the brain ventricle where neuronal progenitor cells are enriched during the late embryo stage, supporting the notion that CDKL3 inactivation contributes to non-syndromic mild MR.

Ependymal areas were studied in the lateral brain ventricles of the rat central nervous system and were labelled with a code. The presented suggestion using the coding for individual ependymal areas in rat ventricle may solve the significant problem in experimental studies, i.e. how to secure the mutual comparison of the same type of ependymal areas or ependymal cells. The periventricular structures represent a basic and stable part of brain nerve tissue and they are localized most closely to the studied part of the ventricle wall. For this quality they were chosen as reference nerve tissue for the labelling of the ependymal areas and they were used for the creation of the code. The code is composed from letters “Lv” (lateral ventricle) and “E” (ependymal area) followed by the abbreviation of the latin name of the periventricular structure, e.g., the corpus callosum abbreviation is “cc”. The code of the ependymal area over the corpus callosum is thus “LvE-cc”. The proposed labelling of the ependymal areas may offer several advantages, such as: (i) better characterization of ependymal areas in the future; (ii) preventing the interchange of different types of ependymal areas or ependymal cells; and (iii) avoiding a false interpretation in experiments.

Multiciliated ependymal (E1) cells line the brain ventricles and are essential for brain homeostasis. We previously identified in the lateral ventricles a rare ependymal subpopulation (E2) with only two cilia and unique basal bodies. Here we show that E2 cells form a distinct biciliated epithelium extending along the ventral third into the fourth ventricle. In the third ventricle floor, apical profiles with only primary cilia define an additional uniciliated (E3) epithelium. E2 and E3 cells' ultrastructure, marker expression and basal processes indicate that they correspond to subtypes of tanycytes. Using sonic hedgehog lineage tracing, we show that the third and fourth ventricle E2 and E3 epithelia originate from the anterior floor plate. E2 and E3 cells complete their differentiation 2–3 weeks after birth, suggesting a link to postnatal maturation. These data reveal discrete bands of E2 and E3 cells that may relay information from the CSF to underlying neural circuits along the ventral midline., Ependymal cells lining the adult brain ventricles are comprised of multiciliated cells and a rare subpopulation with two cilia (E2 cells) whose origin and function remain unknown. Here the authors find E2 cells in the 3rd ventricle of mice and humans, along with a third ependymal cell type with only a primary cilium, and provide details of their marker profile and developmental origins.

The size of brain ventricles is especially relevant in some brain diseases such as epilepsy, schizophrenia and other neurodegenerative diseases. Many studies have been conducted to assess the brain ventricles. To the best of our knowledge, however, there is no fourth, third and lateral ventricles volume study evaluating the efficiency and accuracy of point-counting and planimetry methods of the Cavalieri principle in the literature. In the current study, we estimated the volume of intracerebral ventricles in normal subjects using stereological methods. The volumes of fourth, third and lateral ventricle were estimated in 14 young Turkish volunteers ( 7 males and 7 females), aged between 18 and 36 years and free of any neurological symptoms and signs, using serial magnetic resonance imaging (MRI). Volumes of intracerebral ventricles were determined on MRIs using the point-counting and planimetry methods. The mean results of the point-counting method were 14.7 +/- 4.2, 8.7 +/- 3.0 and 131.8 +/- 33.1 mm(3) for the fourth, third and lateral ventricles, respectively. The mean results of the planimetry method were 15.4 +/- 3.4, 8.6 +/- 3.5 and 153.7 +/- 34.6 mm(3) for the fourth, third and lateral ventricles, respectively. Ventricle volumes obtained by the two different methods were not statistically different ( p > 0.05) and they correlated well with each other. Good agreement was found between results obtained with the point-counting and planimetry techniques. The findings of the present study using stereological methods could provide data for the evaluation of normal and pathological volumes of intracerebral ventricles., The size of brain ventricles is especially relevant in some brain diseases such as epilepsy, schizophrenia and other neurodegenerative diseases. Many studies have been conducted to assess the brain ventricles. To the best of our knowledge, however, there is no fourth, third and lateral ventricles volume study evaluating the efficiency and accuracy of point-counting and planimetry methods of the Cavalieri principle in the literature. In the current study, we estimated the volume of intracerebral ventricles in normal subjects using stereological methods. The volumes of fourth, third and lateral ventricle were estimated in 14 young Turkish volunteers (7 males and 7 females), aged between 18 and 36 years and free of any neurological symptoms and signs, using serial magnetic resonance imaging (MRI). Volumes of intracerebral ventricles were determined on MRIs using the point-counting and planimetry methods. The mean results of the point-counting method were 14.7 +/- 4.2, 8.7 +/- 3.0 and 131.8 +/- 33.1 mm(3) for the fourth, third and lateral ventricles, respectively. The mean results of the planimetry method were 15.4 +/- 3.4, 8.6 +/- 3.5 and 153.7 +/- 34.6 mm(3) for the fourth, third and lateral ventricles, respectively. Ventricle volumes obtained by the two different methods were not statistically different (p > 0.05) and they correlated well with each other. Good agreement was found between results obtained with the point-counting and planimetry techniques. The findings of the present study using stereological methods could provide data for the evaluation of normal and pathological volumes of intracerebral ventricles.

Introduction Intraparenchymal, multimodality sensors are commonly used in the management of patients with severe traumatic brain injury (TBI). The ‘gold standard’, based on accuracy, reliability and cost for intracranial pressure (ICP) monitoring is within the cerebral ventricle (external strain gauge). There are no standards yet for intracerebral temperature monitoring and little is known of temperature differences between brain tissue and ventricle. The aim of the study therefore was to determine pressure and temperature differences at intraparenchymal and ventricular sites during five days of continuous neuromonitoring. Methods Patients with severe TBI requiring emergency surgery. Inclusion criteria: patients who required ICP monitoring were eligible for recruitment. Two intracerebral probe types were used: a) intraventricular, dual parameter sensor (measuring pressure, temperature) with inbuilt catheter for CSF drainage: b) multiparameter intraparenchymal sensor measuring pressure, temperature and oxygen partial pressure. All sensors were inserted during surgery and under aseptic conditions. Results Seventeen patients, 12 undergoing neurosurgery (decompressive craniectomy n = 8, craniotomy n = 4) aged 21–78 years were studied. Agreement of measures for 9540 brain tissue-ventricular temperature ‘pairs’ and 10,291 brain tissue-ventricular pressure ‘pairs’ were determined using mixed model to compare mean temperature and pressure for longitudinal data. There was no significant overall difference for mean temperature (p = 0.92) or mean pressure readings (p = 0.379) between tissue and ventricular sites. With 95.8 % of paired temperature readings within 2SD (−0.4 to 0.4 °C) differences in temperature between brain tissue and ventricle were clinically insignificant. For pressure, 93.5 % of readings pairs fell within the 2SD range (−9.4756 to 7.8112 mmHg). However, for individual patients, agreement for mean tissue-ventricular pressure differences was poor on occasions. Conclusions There is good overall agreement between paired temperature measurements obtained from deep white matter and brain ventricle in patients with and without early neurosurgery. For paired ICP measurements, 93.5 % of readings were within 2SD of mean difference. Whilst the majority of paired readings were comparable (within 10 mmHg) clinically relevant tissue-ventricular dissociations were noted. Further work is required to unravel the events responsible for short intervals of pressure dissociation before tissue pressure readings can be definitively accepted as a reliable surrogate for ventricular pressure.

We studied modifications in the mass electrical activity of the cortex (ECoG) induced by injections of thyrotropin-releasing hormone (TRH) into the left or right lateral brain ventricle in rats kept under conditions close to free behavior. It was found that these effects are characterized by a significant interhemisphere asymmetry. We postulate that the pharmacological (in particular, antidepressive) effects of TRH are related to its ability to intensify inhibitory processes in the left cerebral hemisphere and activating processes in the right hemisphere.

There were studied effects of administration into brain ventricle of Wistar rats of the 1–10 kDa fractions (BAF) isolated from the brain of the black bear Ursus arctos caught in winter at exit from the den after the provoked awakening. Injection of BAF at a doze of 0.1 mg decreased motor activity and produced a sleep-like state of rats. Phases of the slow-wave EEG activity, with an enhancement of δ- and suppression of α- and β-frequencies, alternated with θ-rhythm periods. An intranasal BAF injection to white breedless mice previously cooled to 17–19°C under conditions of hypoxia-hypercapnia decelerated the exit of the mice from the hypothermia state.

The subcommissural organ (SCO) and the floor plate (FP) secrete high molecular weight glycoproteins that polymerize in the form of the Reissner's fiber (RF). To study to what extent the absence of the FP affects the expression of these glycoproteins, we have investigated the brain and spinal cord of 48-h and 72-h wildtype and cyclops (cyc) mutant zebrafish larvae by using a polyclonal antiserum against bovine RF. Wildtype larvae showed immunoreactivity in the SCO at the dorsal forebrain-midbrain boundary. In the ventricle, over the SCO surface, thin immunoreactive fibers aggregated into an RF that ran along the third and fourth ventricles and the central canal of the spinal cord until, at its caudal end, the fiber disintegrated and formed a strongly immunoreactive massa caudalis that left the neural tube and invaded the surrounding tissues of the tail fin. The rostral end of the FP, lining the pontine flexure, was also strongly immunoreactive, as was the caudal third of the FP. Cyc mutants showed an immunoreactive SCO and fibrous material in the ventricle, but an RF was missing. There was no label in the ventral midline of the neural tube except in some specimens in which the caudal FP persisted and was immunoreactive. It is concluded that the product of the cyc gene is not required for the expression of SCO glycoproteins but for their polymerization into an RF in the brain ventricles.

The neuroanatomical correlates of temperament in human have been examined extensively but not comprehensively. Most studies have focused on certain brain regions of gray and white matter, such as prefrontal cortex, amygdala, anterior cingulate cortex, etc, however, less is known about the contribution of other areas to human temperament [1-4]. Previous studies have shown that brain ventricle is related to psychiatric diseases, which exemplify problems in self-control, here we sought to explore whether the size of brain ventricle is associated with individual differences in temperament in healthy college students. Thirty-eight subjects (21 males, 17 females, age 18-23 years) were selected randomly, and scanned using a three-dimensional T1-weighted magnetization-prepared gradient echo (MPRAGE) sequence on a Siemens 3T Allegra scanner to acquire anatomic data, which were then segmented by FreeSufer and calculated for volume. Individual temperament was assessed using the Adult Temperament Questionnaire (ATQ)[5], and scores of each scale were then correlated with the ventricular volume. We found a positive correlation between the volume of fourth ventricle and effortful control (one of the four core temperament dimensions in ATQ) in males (r=0.485, p=0.026), suggesting that males with larger fourth ventricle volume, have great capacity to focus and direct attention, and inhibit inappropriate behavior. However, no significant correlation was detected in females.

Background It has long been known that cerebrospinal fluid (CSF), its composition and flow, play an important part in normal brain development, and ependymal cell ciliary beating as a possible driver of CSF flow has previously been studied in mammalian fetuses in vitro. Lower vertebrate animals are potential models for analysis of CSF flow during development because they are oviparous. Albino Xenopus laevis larvae are nearly transparent and have a straight, translucent brain that facilitates the observation of fluid flow within the ventricles. The aim of these experiments was to study CSF flow and circulation in vivo in the developing brain of living embryos, larvae and tadpoles of Xenopus laevis using a microinjection technique. Methods The development of Xenopus larval brain ventricles and the patterns of CSF flow were visualised after injection of quantum dot nanocrystals and polystyrene beads (3.1 or 5.8 μm in diameter) into the fourth cerebral ventricle at embryonic/larval stages 30-53. Results The fluorescent nanocrystals showed the normal development of the cerebral ventricles from embryonic/larval stages 38 to 53. The polystyrene beads injected into stage 47-49 larvae revealed three CSF flow patterns, left-handed, right-handed and non-biased, in movement of the beads into the third ventricle from the cerebral aqueduct (aqueduct of Sylvius). In the lateral ventricles, anterior to the third ventricle, CSF flow moved anteriorly along the outer wall of the ventricle to the inner wall and then posteriorly, creating a semicircle. In the cerebral aqueduct, connecting the third and fourth cerebral ventricles, CSF flow moved rostrally in the dorsal region and caudally in the ventral region. Also in the fourth ventricle, clear dorso-ventral differences in fluid flow pattern were observed. Conclusions This is the first visualisation of the orchestrated CSF flow pattern in developing vertebrates using a live animal imaging approach. CSF flow in Xenopus albino larvae showed a largely consistent pattern, with the exception of individual differences in left-right asymmetrical flow in the third ventricle.

Experimental results are presented which describe induction and pathogenesis of the hydro-micrencephaly in NMRI-mice after single X-irradiation with 0.9 Gy or 1.9 Gy on gestation day (gd) 12. The ultrastructural alterations in the ventricular walls are sequentially investigated up to gross developmental damage. The ventricular zone is the most sensitive region in the developing brain. Its constituting undifferentiated and proliferating cells lose their palisade like orientation and fail subsequently to differentiate into primitive neurons, glia cells, or ependymal cells. Structurally this results in the thinning of ventricular walls by more than 50% associated with periventricular oedema and a dilation of the brain ventricles by 20–60%. Damage is clearly more pronounced with the higher dose. Repair processes originate from regions with intact Zonulae adherentes which give also rise to typical globular or cylindrical heterotopic structures; these are known as rosettes and made up from undifferentiated proliferating ventricular cells. Perinatally in these rosettes cell replication persists, at a time when cell production in the ventricular zone has ceased. Histological changes are most prominent in and around the telencephalic roof consisting in replacement of the ependymal lining by a felt of glial fibers, faulty myelinisation, and periventricular oedema; postnatally these structural alterations lead to hydro-micrencephaly. Results from this animal model can be translated to the human situation because the fundamental developmental processes in the brain of mammals are similar despite species related differences of the time scale.

Agonists of κ1-opiate receptors injected in brain ventricle potentiate arrhythmogenic effect of adrenaline. Antagonist of κ1-opiate receptors norbinaltorphimine or ganglioblocker hexamethonium completely abolish proarrythmic effects of κ1-agonists. Norbinaltorphimine possesses intrinsic antiarrhythmic activity.

The structure of vascular plexuses of brain ventricles in newborns developed under hypoxic conditions does not correspond to gestational age. Chronic hypoxia decreases activity of succinate dehydrogenase and iron content in vascular plexuses of brain ventricles.

Two methods were used to induce a model of experimental hydrocephalus and hydrosyringomyelia in the cat: a) injection of kaolin into the cisterna magna and b) closure of the lateral apertures of the fourth ventricle with cotton swabs. The pathological changes in the brain ventricles and the central canal of the spinal cord were monitored and documented at regular intervals by computed tomography (CT). The CT method is particularly advantageous for studies of this kind because the animals can be examined frequently without risking disturbances in cerebro-spinal fluid dynamics or tissue damage that would result from introduction of contrast media into the ventricular system. Our results and others reported earlier suggest that the dilated central canal acts as a kind of spontaneous CSF deviation route from the ventricles to the subarachnoid space. In spite of the tendency of the animals to recover in a clinical sense, the internal CSF space continued to expand; in cats the disease is progressive, a fact that is readily evident in follow-up CTs. This characteristic indicates that the spontaneous "shunt system" from the fourth ventricle through the dilated central canal to the spinal CSF spaces does not function well enough. Possible explanations for hydrocephalus compensation and the development of hydrosyringomyelia in experimental animals are discussed.

In 6 years 26 adult patients with chronic communicating or non-communicating hydrocephalus underwent ventricular fluid pressure (VFP) recording, including intraventricular steady-state and bolus infusion tests. Patients were treated with a shunt when steady-state infusion yielded a csf outflow resistance (Rcsfs) greater than 10 mm Hg/ml/min; the success rate was 83%. The main purpose of the study was to compare Rcsfs with outflow resistance obtained by bolus infusions (Rcsfb), pressure-volume index (PVI) and VFP. Rcsfs was higher than Rcsfb, particularly when resistance was high and the degree of disturbance of csf dynamics was reflected by Rcsfs better than by Rcsfb. The PVI showed a roughly inverse relationship with the Rcsfs but was not helpful in differentiating arrested from non-arrested hydrocephalus. Rcsfs and VFP correlated better than expected. A high Rcsfs was associated with an elevated VFP and a normal Rcsfs with a normal VFP. VFP only varied when Rcsfs exhibited a mild to moderate increase. It is concluded that steady-state infusion remains the most reliable method for the prediction of the result of shunting. We recommend shunting when Rcsfs is greater than 10 mm Hg/ml/min. Bolus infusions provide valuable data on brain elastance and additional information on csf outflow resistance. VFP recording is certainly worthwhile because infusion tests can be omitted when VFP is clearly elevated and useful information is obtained when Rcsf is borderline.

An unusual cell type consisting of free elements widely scattered over the marginal epithelium of the rat pituitary cleft is revealed by SEM. Most of these supramarginal cells characteristically have irregularly shaped cell bodies from which thin branched processes extend. Supramarginal cells bear resemblances to Kolmer (epiplexus) cells and to supraependymal cells of the brain ventricles. Their ultrastructural features make it probable that supramarginal cells are phagocytes, and can be regarded as scavengers of the cleft. Considering the close topographical association between the hypophysial cleft and the floor or the 3rd ventricle, supramarginal cells may be members of the motile macrophagic Kolmer cells populating the ventricular surfaces of the brain.

1. A shivering-like state of tremor was induced, in steroid-anesthetized cats, by perfusing the brain ventricles with a solution of d-tubocurarine in artificial spinal fluid. The behaviour of spinal α- and γ-motor systems and of muscle spindle afferents, belonging to hindlimb extensor and flexor muscles, was investigated by electrophysiological methods.

Unter etwa 3000 encephalographierten Kranken mit den verschiedensten nervosen und psychischen Erkrankungen boten 31 im Encephalogramm das Gegenteil eines Hydrops ventriculorum, namlich eine erheblich von der Norm abweichende Verkleinerung der Ventrikel („Mikroventrikulie“).

The behavioural effects of NA injected without narcosis into the lateral brain ventricle of the rats were studied with two different techniques. Rats were classified according their normal level of exploratory activity into three groups: high, medium and low. It was shown that NA in a dose of 10 μg increased locomotor activity only in animals of low activity; a dose of 50 μg increased locomotor activity in all the animals; and a dose of 200 μg induced a complete abolition of locomotor activity and a stuporose syndrome lasting 2 hours. The evidence that NA in some experimental conditions increases locomotor activity of rats supports the hypothesis that NA regulates processes in the central nervous system which stimulate behaviour.

Ein Netzwerk aus Axonen, Nervenzellen und Gliazellen breitet sich auf der Liquorseite der Ependymzellauskleidung der Apertura lateralis des Gehirns vom Kaninchen aus. Axone verschiedenen Kalibers treten durch das Ependym der Ventrikelwand und verlaufen zwischen den Kinozilien parallel zur Ventrikeloberflache. Zum Teil verbleiben sie an der apikalen Oberflache des Ependyms, zum Teil flottieren sie einzeln oder in Bundeln, die einander rechtwinklig kreuzen konnen, offenbar frei im Liquor. Die Axone zeigen Endkolben und spindelformige Verdickungen ihres Querschnitts, die wegen ihres Reichtums an Mitochondrien fur Rezeptoren gehalten werden konnen. An Stellen, an denen Axone einander oder Ependymzellen beruhren, werden synapsenartige Strukturen gefunden. Die meisten Axone sind markscheidenfrei, werden aber teilweise von Gliazellen umscheidet, die die Mehrzahl der supraependymalen Zellen ausmachen. Wenige Nervenzellen — sie sind erheblich groser als die Gliazellen — haben Anteil an dieser Organisation.

Mit der Perjodsaure-Bisulfit-Aldehydthionin-Farbung (Specht) lassen sich am ganzen Ventrikelsystem des Rattengehirns sub- und interependymale Strukturen lichtmikroskopisch nachweisen, die elektronenmikroskopisch als Basalmembranlabyrinthe (BML) identifiziert werden konnen. Verschiedene Formen dieser BML lassen sich unterscheiden. Sie stehen in Verbindung mit subependymalen Kapillaren. Die Verteilung der BML wird in Ventrikelkarten dokumentiert.

The pineal complex of the coelacanth, Latimeria chalumnae was studied light and electron microscopically. It consists of two vesicles representing parapineal and pineal organs. Both occur intracranially and openly communicate with each other and the brain ventricle. The entire complex shows a striking photoreceptor morphology with sensory, ependymal and nerve cells. The last cell type is more abundant in the parapineal vesicle than in the pineal organ. The following ultrastructural details of the parapineal are noteworthy: 1. The sensory cells possess large inner and outer segments protruding freely in the vesicular cavity. The outer segments measure 8-10 mum in length and consist of as many as 275 lamellae. The basal processes of these cells terminate in neuropil-like regions. Occasionally, dense granules (500-1000 A) of uncertain identity occur in the perinuclear and inner segment cytoplasm of the cells. 2. The supporting cells are of the ependymal type. Their cytoplasm contains a filamentous feltwork and pinocytotic vesicles, but lacks secretory granules. Cytosomes are particularly abundant in cell processes in the neuropil-like zones. The basal end-feet of these cells isolate the receptor and nerve cells from the perivascular space. 3. In the neuropil-like regions, terminals of sensory cells make synaptic contacts with neuronal dendrites. Synaptic ribbon-like profiles in the terminals characterize the contact zones. Only unmyelinated nerve fibers could be observed in the small area of the tissue examined. The results are discussed with regard to photoreceptive and secretory functions of the pineal complex and its evolution in lower vertebrates.

The scanning electron microscope was used to survey the brain ventricular system of the female armadille (Dasypus novemcinctus) with emphasis on the third ventricle. The walls of the lateral ventricles, aqueduct, and fourth ventricle are covered by long cilia. In the lateral ventricle, the cilia are arranged in groups; but in the aqueduct and fourth ventricle, they are evenly placed over the cellular surfaces. The ependymal cells of the third ventricle are densely ciliated except for the organum vasculosum and infundibular recess. The non-ciliated luminal surface of these areas has a pebblestone appearance punctuated by numerous microvilli and two types of supraependymal cells.