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At least 253 records · Page 14Linked to original sources
PubMed2000

Patterns of calretinin, calbindin, and tyrosine-hydroxylase expression are consistent with the prosomeric map of the frog diencephalon.

This paper re-examines a previously published segmental map of the frog diencephalon (Puelles et al. [1996] Brain Behav.Evol. 47:279-310) by means of immunocytochemical mapping of calretinin, calbindin, and tyrosine hydroxylase. The distribution of neuronal populations, axon tracts, and neuropils immunoreactive for these markers was studied in adult specimens of Rana perezi and Xenopus laevis sectioned sagittally or horizontally. Emphasis was placed on study of the relationship of observed chemoarchitectural boundaries with the postulated overall prosomeric organization and the schema of nuclear subdivisions we reported previously, based on acetylcholinesterase histochemistry and Nissl pattern in Rana. The data reveal a large-scale correspondence with the segmental map in both species, although some differences were noted between Rana and Xenopus. Notably, retinorecipient neuropils were generally immunoreactive for calretinin only in Rana. Importantly, calretinin immunostaining underlines particularly well the transverse prosomeric boundaries of the dorsal thalamus. A number of nuclear subdivisions noted before with AChE were corroborated, and some novel subdivisions became apparent, particularly in the anterior nucleus of the dorsal thalamus and in the habenular complex. The mapping of tyrosine hydroxylase clarified the segmental distribution of the catecholaminergic cell groups in the frog forebrain, which is comparable to that observed in other vertebrates.

Animals↗
PubMedDate not supplied

[Dopamine receptors of the diencephalon associated with the endocrine function of the hypophyseal-testicular system].

One hour after local administration of 1 gamma of dopamine into the medial portion of the subthalamus or into the central grey matter of the caudal portion of the thalamus of male Wister rats testosterone level (determined fluorimetrically) more than doubled in the peripheral blood plasma. A similar effect was produced by apomorphine (2 gamma), stimulant of dopamine receptors, administered into the same areas of the diencepalon. No increase in testosterone content followed local administration of dopamine into the arcuate nuclei of the hypothalamus. A conclusion was drawn that dopamine receptors of the diencephalon associated with the endocrine function of the male gonad were located in the medial portion of the subthalamus and in the area of the central grey matter of the posterior portion of the thalamus. At the same time, dopamine neurons of the arcuate nuclei of the hypothalamus apparently took no part in the regulation of the endocrine function of the hypophysio-testicular system.

Animals↗
PubMed1976

Chemo-architectonic studies in a submammalian brain. Adenosine triphosphatase and simple esterase in the diencephalon and mesencephalon.

The present report deals with the histo-enzymological mapping of adenosine triphosphatase and simple esterase in the diencephalon and mesencephalon of Uromastix hardwickii. The enzymatic make-up, in both cases, does not differ markedly in the various nuclei; few variations, of course, occur in some midbrain areas like pretectal nuclei. The latter are intensely positive for ATPase, while these nuclei are moderate to simple esterase. Nevertheless, one of the most interesting results pertaining to simple esterase activity is of a high order in the fiber tracts in comparison to ATPase. The other interesting feature relates to the fact that generally intensely positive nuclei, in ATPase preparations, are those which have extensive efferent fibres. The metabolic significance of high degree of ATPase activity vis-a-vis extensive efferent connections has been exhaustively discussed, besides the possible significance of the general data obtained.

Adenosine Triphosphatases↗
PubMed1990

[Retinal projections into the diencephalon in the fowl (Gallus gallus domesticus)].

The localization of the primary visual centers in the hen diencephalon was determined by anterograde transport horseradish peroxidase (HRP) techniques. Twelve fowls (Gallus gallus domesticus) were used for HRP study and four were used for cytoarchitectural study (Nissl and Klüver-Barrera stained preparation). One-hundred microliter of 30% HRP solution in physiological saline was injected into the vitreous body of one eye of each hen under anesthesia of sodium pentobarbital (30 mg/kg body wt). After a postoperative period of 48 hours, the animals were deeply anesthetized and perfused with an injection of 1,000 ml of Ringer solution which was followed by 2,000 ml of 1% paraformaldehyde and 1.25% glutaraldehyde in a 0.1 M phosphate buffer (pH 7.4) which was then followed by 1,000 ml of 10% sucrose in the same buffer. The brain was cut into serial transverse sections of 60 microns on freezing microtome. Every section was treated with tetramethylbenzidine (TMB). Retinal projections were found in the hypothalamic area, lateral geniculate nucleus (GL), lateral part of dorsolateral thalamus (DLL), medial part of dorsolateral thalamus (DLM), ventrolateral thalamus (VLT), rostrolateral part of dorsolateral anterior thalamus (DLAlr), magnocellular part of dorsolateral anterior thalamus (DLAmc), lateral anterior thalamus (LA), ectomammillary nucleus (EM), external nucleus (NE), and nucleus superficial synencephalica (SS), contralaterally. No labeled terminals were found in the ipsilateral brain stem. In the hypothalamic region, terminals were found to be just lateral to the rostral part of the third ventriculus and the bottom of the lateral margins of the hypothalamus, which we termed medial (MRH) and lateral (LRH) retinorecipient hypothalamic nucleus. LRH had high density terminals compared with MRH and caudal MRH continued into rostral LRH so that there was no boundary between MRH and LRH in HRP preparation. MRH is contained large cells (25-35 microns in diameter) and occupied rostral 1/4 of retinorecipient of hypothalamus (RH), whereas LRH contained small type cells (about 15 microns in diameter) and occupied caudal 3/4 of RH. In the retinorecipient nuclei of the thalamus, high density terminals were found in GL, LA, DLAlr, NE, SS and EM. In DLAlr and EM, granulae of HRP product were bigger than in other terminal nuclei and also the density of those terminals was high. GL and LA have large nuclei which receive retinal afferents. Labeled terminals of those nuclei were distributed homogeneously throughout the whole nucleus except for the inner layer of GL. Cytoarchitectonically, GL was divided into two layers.

Animals↗
PubMed1975

Effects of electrical stimulation of the mesencephalon and diencephalon on the paradoxical phase of sleep.

During paradoxical sleep electrical stimulation of the mesencephalic reticular formation and emotiogenic structures in the mesencephalon and diencephalon produced depression or an increase in the theta rhythm of the hippocampal and entorhinal electrical activity. However, stimulation not involving behavioral arousal did not cause a transition from paradoxical phase into slow wave sleep. The cessation of stimulation restored the normal structure of the paradoxical phase. Stimulation of the reticular formation causing the depression of the hippocampal and entorhinal theta rhythm without behavioral arousal did not affect duration of the paradoxical phase, which was shortened, however, by electrical stimulation of the emotiogenic structures evoking an increase in the hippocampal and entorhinal theta rhythms. Stimulation of ventromedial hypothalamus or septum (during wakefulness inhibiting motivational behavior and emotional stress) caused transition from the paradoxical into slow wave sleep. This is probably caused by a decrease in emotiogenic stress, which during the paradoxical phase is usually on a high level.

Animals↗
PubMed1991

Two locomotor strips in the diencephalon of thalamic cats.

Electrical stimulation of the subthalamic locomotor region (SLR) can induce locomotor movements in thalamic cats. The possibility of inducing locomotor movements from other structures in the diencephalon, using electrical stimulation, was investigated in acute thalamic cats. It was found that the area from which locomotor movements could be elicited, extended caudally to the SLR and formed two strips: (1) the dorsal strip, located at the border of the ventral thalamus and dorsal hypothalamus, and (2) the ventral strip, extending ventrally beneath the red nucleus.

Animals↗
PubMed1988

Immunocytochemical study of substance P-like fibres and cell bodies in the cat diencephalon.

The distribution of fibres and cell bodies containing substance P in the diencephalon of the cat was studied using an indirect immunoperoxidase technique. A high density of both immunoreactive fibres and perikarya was observed in the nuclei habenularis lateralis, periventricularis anterior, arcuatus, supraopticus and supra chiasmaticus, whereas the area hypothalamica dorsalis, the nucleus periventricularis hypothalami and the hypothalamus ventromedialis showed dense plexuses of fibres and moderate concentrations of cell bodies. In the hypothalamus lateralis a low number of fibres and perikarya was found, whereas a rich cluster of substance P cell bodies and scarse fibres were observed in the hypothalamus posterior. Moreover, a dense network of immunoreactive fibres was located in the nuclei lateralis dorsalis, medialis dorsalis, centralis medialis (caudal part) and parataenialis, whereas a moderate number was observed in the nuclei centralis medialis (rostral part), anterior dorsalis, rhomboidens, reuniens, interanteromedialis and filiformis. The hypothalamus anterior had a low density. Finally, a large population of perikarya was observed in the median eminence and regio praeoptica. In the nuclei habenularis medialis, parafascicularis and centrum medianum scarse cell bodies were found.

Animals↗
PubMed1989

[Changes in carbohydrate metabolism before and after the development of focal cerebral ischemia. III. Function of the diencephalon].

The purpose of the investigation was to assess whether the mechanism of reduced glucose tolerance in focal ischaemia of the brain can be considered a functional disorder of the regulatory brain centres or a manifestation of inadequate glucose utilization due to impaired insulin secretion. The function of centres regulating metabolic processes was tested by the i.v. administration of Pyrifer. It was revealed that after Pyrifer administration a parallel rise of the investigated values does not occur (i.e. number of leucocytes, body temperature, pulse, systolic and diastolic pressure, blood sugar level), the maximum values do not reach the levels of the control group, their rise is retarded, persists twice as long as in the control group and does not return to baseline values in the appropriate time. A pathological constellation of responses was recorded in 85.71% of the cases. A similar trend of changes was found also in a group of arteriosclerotic and hypertonic patients although in a lower percentage. The results confirmed the assumption that in the mechanism of reduced glucose tolerance in the periphery an important part is played by the impaired function of regulating centres in the diencephalon.

Adult↗
PubMed1986

[Catecholaminergic centers of the sheep encephalon. Immunocytochemistry. II. Mesencephalon and diencephalon].

In the sheep, the structures exhibiting the whole of catecholaminergic containing perikarya of the sheep myelencephalon and metencephalon were studied in a previous work using tyrosine hydroxylase immunocytochemistry. Mesencephalon and diencephalon were investigated in the same way here. As seen in the precedent paper, catecholaminergic perikarya were more scattered in homologue structures of the sheep, as compared with the rat. Immunocytochemistry revealed more labeled structures than did the histochemical fluorescence method, suggesting a possible lack of dopadecarboxylase in these structures, that are not marked by the Falck technique.

Animals↗
PubMed1986

Specific somatic sensory relays in the mammalian diencephalon.

There are five major domains within the diencephalon that receive input from ascending somatic sensory pathways serving the limbs, trunk and viscera. These domains include the ventroposterolateral nucleus (VPL), the posterior group complex (PO), the zona incerta (ZI), the intralaminar complex and the thalamic reticular nucleus. Of these five domains, VPL is commonly considered a "specific" somatic "relay". The reasons for this view are that VPL receives dense, synaptically secure and precisely organized input from the equally precisely organized dorsal column nuclei (DCN), that most of VPL's neurons have small, unimodal cutaneous receptive fields which reflect their input from DCN, and that these neurons project this information in a precise way to the somatic sensory cortex. Several lines of evidence suggest that this rather simple view of VPL be modified. First, not only does VPL receive complex patterns of partially converging input from other ascending somatic pathways besides the DCN, but the pattern of its input from DCN appears to be more complex than once thought. Second, such input convergence and complex connective patterns also occur within PO and ZI (although the characteristics of the patterns differ between the three domains). Third, the response properties of neurons within VPL differ in its different parts and are not necessarily precise mirrors of the response properties of neurons within DCN. Fourth, although the responses of neurons in PO on the whole differ from those in VPL, there are some similarities. The same conclusion may prove true for neurons in the DCN-recipient portion of ZI.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMedDate not supplied

[The low-frequency EEG component in the healthy subject and its changes as affected by acutely developing foci at the level of the diencephalon and brain stem structures].

The data are given of the analysis of the low-frequency EEG component (LF EEG--0.2--2.0 Hz) of 34 healthy subjects and 36 patients examined in dynamics in the acute period after operations: ablation of a tumour localized at the level of the diencephalon and the level of the brainstem. The LF EEGs were analyzed by a special program: auto- and crosscorrelation functions and power spectra were estimated. In the norm LF EEGs were characterized by mosaics, various frequencies and periodicity in various cortical areas, they appeared with interhemispheric asymmetry, depended on the EEG type--dominance or lack of the alpha-rhythm. In patients in the post-operative period the LF EEGs were changed; in favourable terminations, at first the period of oscillations and the coefficient of correlation increased, then they tended to normalization. In unfavourable terminations, with gross pathological foci in these areas, the LF EEGs acquired a synchronized character, with a higher frequency than in the norm.

Acute Disease↗
PubMed1986

Immunohistochemical study of the distribution of vasotocin reacting neurons in avian diencephalon.

Vasotocin (VT)- and neurophysin (NPH)-containing neurons were immunocytochemically demonstrated in the diencephalon of the Japanese quail (Coturnix coturnix japonica), domestic fowl (Gallus gallus), and Pekin duck (Anas platyrhynchos). In these three avian species, the immunoreactive cells are similarly distributed into three different diencephalic regions: lateral (L), periventricular (P), and dorsal diencephalic (DD). A different number of cell clusters can be easily identified in each region according to its topographical location. Interspecific differences depend on the total number of immunoreactive cells, the cell sizes and the density in each cell cluster. Present results show that the nomenclature of the VT-system originally proposed for the pigeon can be easily applied to all the avian species so far topographically studied. The group nomenclature based only upon the location of immunoreactive elements may avoid potentially inaccurate mammalian homologies, and makes easier the comparison between studies performed in different birds.

Animals↗
PubMed1979

Effects of intraventricular and intra-aquaductal 6-hydroxydopamine on monoamine containing neurons of the fowl paleostriatum, diencephalon and mesencephalon.

The effects of a single intraventricular or intra-aquaductal infusion of 6-hydroxydopamine (6-OHDA) on monoamine fluorescence in the paleostriatum augmentatum, diencephalon and mesencephalon were studied. Present experiments have enable us to better characterize the distribution of catecholaminegic axons in the paleostriatum augmentatum, preoptic area, hypothalamus, median eminence, periventricular areas as well as of cell-bodies and axons exbiting green fluorescence in the n. mesencephalicus properties and other mesencephalic nuclei.

Animals↗
PubMed1984

Histochemical mapping of ATPase and 5'-nucleotidase in the telencephalon and diencephalon of mouse.

The paper deals with a detailed histochemical mapping of adenosine triphosphatase (ATPase) and 5'-Nucleotidase (5'-N) in the telencephalon and diencephalon of mouse. The majority of brain matter nuclei demonstrated high activity for ATPase while, in contrast, only a few nuclei revealed high intensity of 5'-N. In general, the neuronal population dominated in ATPase activity as compared to the neuropil. The highest ATPase activity was observed in the cerebral cortex, nucleus caudatus-putamen, hippocampus, habenular complex and hypothalamus as compared to the thalamus, subthalamus and metathalamus. The motor dominating regions have indicated, invariably, intense ATPase activity than the sensory dominating or sensory-motor nuclei. The highest 5'-N activity was observed in nucleus caudatusputamen, globus pallidus, induseum griseum, nucleus amygdaloideus anterior, nucleus amygdaloideus centralis and nucleus accumbens. The heterogeneous distribution of 5'-N activity was observed in the different regions of hippocampus ranging from mild through moderate to very intense. The brain matter nuclei which dominated with the myelinated fibers demonstrated very intense 5'-N activity. The significance of ATPase and 5'-N has been discussed in relation to the nature of brain matter nuclei and fiber tracts.

5'-Nucleotidase↗
PubMed1982

[Spectrofluorometric determination of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in rat diencephalon (author's transl)].

A spectrofluorometric method to determine 5-HT and 5-HIAA in rat diencephalon has been developed, following the criterion of unifying the methodology in determining biogenic amines and their metabolites. Linearity in the method remains in the interval between 0.01 microgram and 0.05 microgram. Recovery is about 70% for amine and about 80% for the metabolite. Highest concentrations of 5-HT appear in one month old female animals, and are significantly higher than those found in the male population of the same age. Concentrations in two month old animals decrease, without significant differences between males and females. Values found for 5-HIAA seem not to change so significantly, although a slight decrease is observed in the elder males.

Age Factors↗
PubMed1980

Distributive patterns of 5'-nucleotidase and simple esterase in the diencephalon and mesencephalon of the garden lizard (Calotes versicolor).

Different enzymatic patterns of 5'-nucleotidase and simple esterase have been observed in the diencephalon and mesencephalon of the garden lizard, Calotes versicolor. Most of the brain centers have shown the enzyme activities, ranging from negligible through very strong, in the neurons and neuropil. However, two brain centers, the DLH and NM, were found negative to 5'-nucleotidase. On the other hand, no brain center showed negative picture in the preparations of simple esterase. In general, it has been observed that the enzyme activity dominates in the neurons than the neuropil both for 5'-nucleotidase and simple esterase. The major fiber tracts have shown mild reaction product of 5'-nucleotidase except a solitary fiber bundle, the lateral forebrain bundle, which demonstrated, invariably, strong to very strong enzyme activity; the commissura colliculi superioris was, however, negative for the enzyme activity. On contrary, most of the fiber tracts showed strong to very strong activity of simple esterase. The significance of the distributive patterns of the two enzymes in relation to various brain centers and fiber tracts has been discussed.

5'-Nucleotidase↗
PubMed1982

Germ-cell tumors of the diencephalon.

Germ-cell tumors arising in the neuraxis have similar histopathological characteristics to those germ-cell tumors occurring in the gonads and other midline body sites. As a rare cause of intracranial neoplasm, germ-cell tumors affect predominantly the diencephalon and in particular the pineal region and suprasellar structures. Clinical features are due to local infiltration of these areas by tumor and hydrocephalus. Germinomas or mixed-cell tumors with a germinoma component make up the majority of these tumors and are very responsive to irradiation and chemotherapy. Early clinical recognition of a diencephalic tumor and determination of the specific tumor-cell type may result in curative treatment by surgery, irradiation and chemotherapy.

Brain Neoplasms↗
PubMed1983

Forward locomotion elicited by electrical stimulation in the diencephalon and mesencephalon of the awake rat.

Stimulation electrodes were implanted in 63 rats at a total of 208 sites in the diencephalon and midbrain. The sites were tested for elicited forward locomotion, i.e., alternate stepping of the forelimbs and/or hindlimbs, while the rats stood on a treadmill belt in a 27 X 9 X 24-cm chamber. Current levels of 50-300 microA and pulse frequencies of 50, 100 and 154 Hz were presented as single 5-sec trains and as 20 repetitive trains of 1-sec duration with a 3-sec intertrain interval. Locomotion was elicited with low current (50 or 100 microA) single trains at 28% of the sites. Of the regions sufficiently well sampled to warrent comparisons, two showed high densities of locomotion-positive sites with single low current trains. They were the medial hypothalamus (the dorsomedial and the posterior nuclei) and the ventral tegmental area. The medial forebrain bundle and the zona incerta were generally positive but many sites in these regions required repetitive trains. Among the regions with few locomotion-positive sites were the subthalamic nucleus, the fields of Forel and the habenular complex. In the dorsal midbrain, in and around the central gray, low current single trains elicited leaping. The results are discussed in terms of the existence of a delimited subthalamic locomotor region and a ventral midbrain locomotor system independent of a dorsal midbrain system.

Animals↗