Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Telencephalon”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1984

An electrosensory area in the telencephalon of the little skate, Raja erinacea.

On the basis of evoked potential and multiple unit responses we identified a pallial electrosensory area that extends throughout the central one-third of the skate telencephalon. This electrosensory area coincides in its mediolateral and rostrocaudal extent with an area of visual responsiveness. Throughout the area peak visual activity is 250-500 micrometers superficial to the maximum electrosensory responses. However, both electrosensory and visual areas appear to be located within the same pallial cell group. The depth and proximity of this pallial area to the lateral ventricle and medial forebrain bundle suggest that it is a subdivision of the medial pallium. Injection of HRP into the area from a glass microelectrode following recordings revealed retrogradely labeled cells in 3 separate diencephalic nuclei, the largest of which, the lateral posterior nucleus, also is responsive to electrosensory stimuli.

Animals↗
PubMed1986

Percentage of relay and intrinsic neurons in two sensory thalamic nuclei projecting to the non-cortical telencephalon in reptiles Caiman crocodilus.

Large injections of horseradish peroxidase were placed in the non-cortical telencephalon in a reptile, Caiman crocodilus. The number of retrogradely labeled and unlabeled neurons in two sensory thalamic nuclei, nucleus rotundus (vision) and nucleus reuniens pars centralis (audition) were counted. The percentage of unlabeled cells in each nucleus was less than 1%. These data suggest that each of these thalamic nuclei contain few, if any, intrinsic or local circuit neurons.

Alligators and Crocodiles↗
PubMed1986

Anatomical identification of an auditory pathway from a nucleus of the lateral lemniscal system to the frontal telencephalon (nucleus basalis) of the pigeon.

Anterograde and retrograde tracing experiments employing WGA-HRP were used to identify an auditory projection area within the frontal telencephalon of the pigeon. The projection originates in a nucleus of the lateral lemniscus, travels with the quintofrontal tract and terminates within nucleus basalis. The location of the projection area and the absence of a thalamic relay in its pathway are consistent with previous reports of short-latency auditory potentials evoked in the vicinity of the nucleus basalis in several avian species.

Animals↗
PubMed1990

Acetylcholine stimulates the secretion of corticotropin-releasing factor from primary dissociated cell cultures of the rat telencephalon and diencephalon.

Corticotropin-releasing factor (CRF-41) immunoreactive neurones in the CNS are widely distributed; although the major concentration is in the parvocellular division of the paraventricular nucleus, there are also large clusters of CRF-containing neurones in the brainstem, limbic system and cerebral cortex. In this study, we sought to determine whether dispersed rat brain cells cultured in vitro are capable of secreting CRF immunoreactivity. In both telencephalic and diencephalic cultures CRF content of the cells increased from day 7 to 28. This effect was greatest in cells raised in media containing 10% fetal calf serum and 10% heat inactivated horse serum as compared with media containing 10% fetal calf serum and 10% NuSerum. Exposure of the cells to 56 mM K+ or to 10(-9) M acetylcholine caused a release of CRF which was calcium dependent. The effect of acetylcholine was antagonised by atropine (10(-6) M). The CRF immunoreactivity in both types of cell produced two peaks on gel chromatography; one of which eluted with the void volume and the other of which co-eluted with standard CRF-41. However, only the mature peptide was detected in media from cells stimulated with potassium. We conclude that cell cultures of the rat diencephalon and telencephalon produce immunoreactive CRF-41 and that immunoreactive CRF-41 secretion in both diencephalic and telencephalic cells is regulated by acetylcholine.

Acetylcholine↗
PubMed1992

A second auditory area in the non-cortical telencephalon of a reptile.

Injections of horseradish peroxidase (HRP) into a caudocentral portion of the non-cortical telencephalon of Caiman known as the dorsolateral area (dorsal ventricular ridge) resulted in retrogradely labeled neurons throughout the entire extent of the ipsilateral nucleus reuniens. HRP-positive cells were most numerous in nucleus reuniens pars diffusa with only sparse labeling of neurons in nucleus reuniens pars centralis. The results of the present experiment, when compared with those of a prior study that determined the telencephalic connections of nucleus reuniens pars centralis, suggested that these two forebrain areas are separate. Staining with succinate dehydrogenase and acetylcholinesterase revealed that nucleus reuniens pars centralis and pars diffusa and their respective telencephalic projection areas can be differentiated on the basis of histochemical features. These findings in Caiman suggest that certain thalamic and telencephalic auditory areas in birds and crocodilians are most likely the result of common ancestry rather than examples of parallel evolution.

Acetylcholinesterase↗
PubMed1993

Age-related changes in neural cell adhesion molecule (NCAM) isoforms in the mouse telencephalon.

The concentrations of different polypeptide isoforms of the neural cell adhesion molecule NCAM were examined in telencephalic and brainstem-cerebellar tissue from groups of young (3 months) and old (25 months) mice. Antibodies against chick brain NCAM were used in immunoblot analyses to quantify 180 (NCAM180) and 140 (NCAM140) kDa NCAM forms in mouse brain samples containing equal amounts of protein. Telencephalic homogenates from the older group exhibited 37% and 31% less NCAM180 and NCAM140 immunoreactivity, respectively, when compared with homogenates from the younger animals. Brainstem-cerebellar homogenates, however, did not express such age-related changes in the two NCAM isoforms. Age-related changes in isoforms labeled by the anti-NCAM antibodies were not evident in synaptic plasma membranes. NCAM180:NCAM140 ratios were 2- to 3-fold greater in the synaptic membranes vs. homogenates for both age groups. These data suggest that expression levels of NCAM180 and NCAM140 are selectively impaired with aging in the telencephalon, whereas the synaptic contents of these molecules appear to be stably regulated.

Aging↗
PubMed1994

Concordance of quantitative damage within the diencephalon and telencephalon following systemic pilocarpine (380 mg/kg) or lithium (3 mEq/kg)/pilocarpine (30 mg/kg) induced seizures.

We tested the hypothesis that a single systemic injection of 380 mg/kg of the muscarinic agonist pilocarpine would produce more diffuse and severe seizure-induced brain damage than a single injection of lithium (3 mEq/kg) followed 4 h later by < 1/10 the dosage of pilocarpine. The hypothesis was not supported; the pattern of quantitative brain damage 50-60 days after the seizures were elicited by either treatment was comparable within the limits of measurement error. Within the diencephalon and subcortical telencephalon the same structures were either damaged in a similar quantitative manner or were spared. Only five of the 119 damaged structures exhibited statistically significant treatment differences at P < 0.01. The results are compatible with the explanation that lithium may enhance the excitotoxic effects of subsequent muscarinic stimulation.

Acepromazine↗
PubMed1983

Hypothalamic self-stimulation in rats with one hemisphere isolated anterior to the midbrain and the other hemisphere devoid of the telencephalon.

The telencephalon was removed unilaterally in rats. In addition, the forebrain of the other hemisphere was isolated from its brain stem by a precollicular transverse cut. This preparation was then tested for self-stimulation via electrodes implanted in the region of the lateral hypothalamus and medial forebrain bundle (LH-MFB) of either hemisphere. Self-stimulation was found to be intact in both hemispheres. Possible pathways connecting the LH-MFB region of one hemisphere to the contralateral diencephalon were also investigated in the bilaterally detelencephalized rat. The technique of retrograde transport of horseradish peroxidase was used for this purpose. Some fibers from the LH-MFB of one hemisphere were found to decussate to the other hemisphere by way of the thalamic commissure. The supraoptic decussation as well as diffusely organized interdiencephalic connections provide additional routes for interhemispheric LH-MFB projections.

Animals↗
PubMed1976

Endotoxin leucoencephalopathy in the telencephalon of the newborn kitten.

Prolonged exposure of the neonatal kitten to a lipopolysaccharide results in a telencephalic leucoencephalopathy characterized by astrogliosis and necrosis. The visceral organs of neonatal kittens and the telencephalon of mature cats are relatively resistent to the adverse effects of this lipopolysaccharide.

Age Factors↗
PubMed1995

Ontogenic expression of the erythroid-type glucose transporter (Glut 1) in the telencephalon of the mouse: correlation to the tightening of the blood-brain barrier.

Since Glut 1 was shown to be highly abundant in brain microvessels, its distribution during early developmental stages seems of importance in respect to the timing of blood-brain barrier (bbb) formation in the developing CNS. Here we have followed the temporal expression of the erythroid-type glucose transporter Glut 1 in the telencephalon of the embryonic and newborn mouse, beginning at the 9th intrauterine day. Glut 1 immunofluorescence staining was done on cryosections using a rabbit polyclonal antiserum to purified human erythrocyte glucose transporter. Endothelial cells resp. capillaries were detected by staining with a rhodamin-coupled Bandeiraea simplicifolia lectin (BSL). In parallel, the developmental tightening of the embryonic bbb was assessed by perfusion of mouse embryos with Trypan blue and horse radish-peroxidase. At E9, prior to the onset of intraneural neovascularization, strong Glut 1 immunoreactivity was found in the whole neuroectoderm but only minor staining was seen in the perineural domain. Glut 1 expression remained uniformly distributed in the intraneural tissue at E10, the beginning of intraneural neovascularization in the mouse. From E11 onwards, Glut 1 immunoreactivity was invisible in neuroepithelial cells, but appeared tightly associated with intraneural capillaries. Perfusion of E12 embryos using trypan blue solution and HRP revealed that most parts of the CNS and spinal cord were impermeable to the tracer substances at that stage. Thus, we suggest that the bbb is established very early in CNS development, probably in the course of intraneural neovascularization. In addition, our data indicate that the restriction of Glut 1 expression to the intraneural capillaries reflects the onset of bbb function in the mouse embryo.

Animals↗
PubMed1996

The prepubertal ontogeny of luteinizing hormone releasing hormone-like immunoreactivity in the diencephalon and telencephalon of the male Meishan pig brain.

Luteinizing hormone releasing hormone (LHRH) is a decapeptide that regulates reproductive function and behaviors in mammalian species. Because of the importance of proper reproductive function and efficiency in agricultural species, we have investigated the prepubertal ontogeny of LHRH-like immunoreactivity (IR) in the male Meishan pig. The Meishan is a Chinese breed known for reproductive traits including increased litter size and precocious puberty, but slow growth and obesity. Brains of animals from gestational day (g) 30, 50, 70, 90 and 110 and postnatal day (pn) 1, 10, 20 and 50 (duration of pregnancy averaged 114 days) were processed using a standard immunohistochemical technique utilizing a commercially available rabbit anti-LHRH antibody. LHRH-IR in cell bodies and fibers was detected at g30 entering the brain via the terminal nerve and in the septal region of the basal telencephalon. The number of immunoreactive cells increased at g50 and cells were localized primarily to the septum, organum vasculosum of the lamina terminalis, preoptic area and lateral hypothalamus, whereas immunoreactive fibers were present throughout the septum and hypothalamus and had reached the median eminence. The density and distribution of immunoreactive fibers increased by g70 and g90, but did not change dramatically from g90 to pn50. These results indicate that LHRH may be present in the Meishan brain earlier during development and fibers containing LHRH-IR appear to reach the median eminence earlier than previously reported for the domestic pig. These results suggest a breed difference in the ontogeny of reproductive control systems in the pig. Future studies utilizing direct comparisons between domestic and Chinese breeds will be required to investigate the apparent differences in the ontogeny of LHRH-containing systems in the pig.

Animals↗
PubMed1980

Removal of the telencephalon spares turning induced by injection of GABA agonists and antagonists into the substantia nigra.

Unilateral injections into the substantia nigra of GABA agonists or the GABA-related agents muscimol (5-50 ng), baclofen (10-50 ng) or B-aminobutyric acid (25-50 ug) induced intensive turning in the direction contralateral to the injected hemisphere. Intranigral injection of the GABA antagonist picrotoxin (100-500 ng) led to ipsiversive turning. Surgical removal of the whole telencephalon (including the neocortex, hippocampus, striatum, septal nuclei and amygdalae) influenced neither direction nor magnitude of the turning responses induced by these various drugs. A GABAergic system in the substantia nigra can, therefore, cause turning independent of telencephalic structures.

Aminobutyrates↗
PubMed1986

Size-threshold changes after lesions of the visual telencephalon in pigeons.

Fifteen pigeons were tested in a psychophysical procedure that determined the limits of their ability to detect differences in the sizes of stimuli. The results indicated that intact pigeons can reliably discriminate an annulus 3.0 mm in diameter from one that is 3.9 mm in diameter. In the first experiment, pigeons with lesions of the ectostriatum that spared the medial 15% were unimpaired in their size-discrimination ability. Those cases in which the lesions involved both the medial and lateral regions of the ectostriatum were greatly impaired. In a second experiment, these findings were replicated. In some cases, the electrode trajectory was varied to rule out possible effects from non-ectostriatal structures. In addition, the second study indicated that destruction of the medial ectostriatum with the lateral regions intact had no measurable effect on size-difference thresholds. The medial region of ectostriatum is part of the termination field of a second tectofugal pathway to the telencephalon. This pathway passes from the optic tectum to nucleus dorsolateralis posterior thalami and then to the neostriatum intermedium, including the medial ectostriatum. An examination of the data of the present experiment and those of other behavioral studies of the ectostriatum suggest that the medial ectostriatum may be involved in the processing of visual information with low spatial-frequency components and the lateral ectostriatum may be processing information about the high-frequency composition of stimuli.

Animals↗
PubMed1991

Ultrastructural localization of telencephalin, a telencephalon-specific membrane glycoprotein, in rabbit olfactory bulb.

Localization of a telencephalon-specific glycoprotein, telencephalin (TCLN), in the olfactory bulb of the rabbit was studied with an electron microscope. Anti-TCLN antisera appeared to stain plasma membrane, Golgi apparatus and multivesicular bodies of granule cells which are local circuit interneurons in the bulb. Principal neurons, mitral and tufted cells, were not immunoreactive. No glial cells showed immunoreactivity. Thus, expression of telencephalin is specific not only to the telencephalic segment of the brain, but also to the neuronal types.

Animals↗
PubMed1992

Distribution of cells containing progesterone receptor mRNA in the female rat di- and telencephalon: an in situ hybridization study.

In an attempt to examine regional synthesis of the progesterone receptor (PR) in the brain, the distribution of mRNA encoding PR was investigated in the female adult rat di- and telencephalon by in situ hybridization using T7 RNA polymerase transcripts of a 320 base pair rat PR cDNA clone. The rat PR cDNA had been partially cloned and sequenced by using the reverse transcription-polymerase chain reaction (RT-PCR) method. The primer set corresponds to a part of the progesterone binding domain of human PR cDNA. Large numbers of strong labeling were observed in the arcuate nucleus, medial preoptic nucleus, and ventrolateral part of the ventromedial nucleus which are relative to sexual behavior. Moderate labeling was found in layers II and IV of the isocortex, in the pyramidal layer of the CA1 and CA3 fields of the hippocampal formation, in the cortical nucleus of the amygdala, in the nucleus of the diagonal band, and in the anterior periventricular nucleus. Weak labeling was found in many other regions. These results were largely in agreement with the distribution of PR previously reported by ligand binding assay and autoradiographic studies. This present in situ hybridization study may provide a useful tool for the analysis of the regional regulation of PR synthesis in the rat brain.

Animals↗
PubMed1995

Cellular distribution in the rat telencephalon of mRNAs encoding for the alpha 3 and alpha 4 subunits of the nicotinic acetylcholine receptor.

Pharmacological and electrophysiological studies provide evidence for the involvement of different nicotinic acetylcholine receptor isoforms in rat neocortical and hippocampal signal transduction. Yet, rather little is known on the cellular localization of these isoforms. With the availability of isoform specific nucleic acid probes and sensitive non-isotopic detection systems, nicotinic receptors can be studied on the mRNA level in individual neurons. In this way, we have paradigmatically studied the distribution of the alpha 3 and alpha 4 isoform mRNAs of the nicotinic receptor in the rat telencephalon. In the cerebral cortex, alpha 3 transcripts were mainly located in pyramidal neurons of layers V and VI and in some non-pyramidal cells in layer IV, while alpha 4 mRNA was detected in different types of neurons located in almost all layers. In the hippocampus, local distribution of both transcripts was comparable. Only very few labeled neurons were observed in the dentate gyrus. In the CA region, the specific mRNAs were detected in pyramidal perikarya and individual neurons in the strata oriens and lacunosum-moleculare. Our data show that the applied method is sufficiently sensitive and isoform-selective in order to study the differential expression of nicotinic receptors on the cellular level in the mammalian brain.

Animals↗
PubMed1989

Electrosensory activity in the telencephalon of the axolotl.

Electrical shock of the anterior lateral line nerve evokes slow wave potentials in the contralateral corpus striatum and bilaterally in the medial pallium of the telencephalon of axolotls. The onset latency of the evoked response in the medial pallium (70 ms) is considerably longer than that of the corpus striatum (46 ms). Quasi-natural stimuli, such as weak uniform electric fields (100 microV/cm) or water drops striking the surface of the water surrounding the axolotls elicited evoked potentials or multiple unit activity in the corpus striatum but not in the medial pallium. Striatal responses to weak electric fields have a threshold of approximately 50 microV/cm and habituate at rates higher than 1 every 10 s. Multiple-unit responses in the medial pallium were elicited only by gentle strokes to the snout with a brush, and it is possible that trigeminal fibers were inadvertently stimulated in the nerve shock cases. The discovery that the corpus striatum is a major telencephalic target of electrosensory information rather than the medial pallium as reported in elasmobranch fishes, suggests that there are additional electrosensory telencephalic centers in elasmobranchs and/or that homologous nuclei of the midbrain or thalamus have evolved different projections.

Action Potentials↗