Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new type of neuron was recognized in the olfactory bulb of the goldfish (Carassius auratus) by means of light and high voltage electron microscopy of Golgi-impregnated material, combined Golgi-electron microscopy, and electron microscopy of serial thin sections. The neuron is located in the layer between the olfactory nerve layer and the anterior olfactory nucleus. It has a spherical cell body, about 10--20 microns in diameter, and several dendrites which form a spherical dendritic field, about 70--100 microns in diameter, in the vicinity of the cell body. The most remarkable structural feature of this neuron is that its initial unmyelinated portion of the axon (IP) has elaborate protrusions with many synapses. The IP can be divided into three parts, parts 1, 2 and 3, based on its structural features. Part 1 is the initial part of the IP, about 20--40 microns in length. Many elaborate protrusions arise from the shaft and intermingle with one another to constitute a spherical field, about 20--40 microns in diameter, around the shaft. Part 2 is the middle part of the IP, about 10--20 microns in length. There are several collateral-like protrusions, which are scattered along the shaft and extended laterally about 5--15 microns. Part 3 is the last part of the IP, and is cylindrical without protrusions. The length of part 3 varies from 20 to more than 100 microns. The axon acquires a myelin sheath at distance of 70--250 microns from its origin. Protrusions make synaptic contacts mainly with granule cell dendrites. Some of them are of the reciprocal type. Protrusion are presynaptic in asymmetrical synapses, and postsynaptic in symmetrical synapses with granule cell dendrites. The shaft of the IP also has synapses similar to those on protrusions. The neuron described is a new type of neuron in the vertebrate central nervous system. We propose for it the name "ruffed cell."
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PMID:Ruffed cell: a new type of neuron with a distinctive initial unmyelinated portion of the axon in the olfactory bulb of the goldfish (Carassius auratus) I. Golgi impregnation and serial thin sectioning studies. 45 34

Monopolar DC-recordings were made of the gross responses from the olfactory bulb of char (Salvelinus alpinus syn. Salmo alpinsus L.) and trout (Salmo trutta L.) during stimulation with different odours. The response features studied were: the magnitude and polarity of the slow potential shift, the amplitude of the induced waves and their asymmetrical waveform. Amino acids elicited the largest responses in the lateral part of the bulb. Water containing "crude fish odour" caused the largest response in the rostral and medial parts. The results demonstrate odour specific differences in the localization of the bulb responses and the separate origin of the slow potential and the induced waves.
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PMID:The spatial distribution of odour induced potentials in the olfactory bulb of char and trout (Salmonidae). 62 99

1. In the rabbit olfactory bulb, analysis has been carried out on intracellular potentials recorded from mitral cells and neurones in the granule cell layer (g.c.l. cells) in addition to the extracellular field potentials in the olfactory bulb elicited by anterior commissure (a.c.) stimulation. 2. Most mitral cell recordings showed i.p.s.p.s with latency of 7-11 msec following a.c. stimulation. These i.p.s.p.s were similar to those evoked by lateral olfactory tract (l.o.t.) stimulation in their sensitivity to internally applied current and showed asymmetrical reversal during application of the hyperpolarizing current. 3. Volleys in the a.c. elicited e.p.s.p.s in type 1 g.c.l. cells whose characteristics were in agreement with those of inhibitory interneurones inferred from the analyses of mitral cell i.p.s.p.s. It has been suggested that these type 1 g.c.l. cells may be the common inhibitory interneurones (presumably granule cells) mediating both a.c.-evoked and l.o.t.-evoked i.p.s.p.s in mitral cells. 4. Conditioning a.c. stimulation depressed the test l.o.t.-evoked i.p.s.p.s in mitral cells and test l.o.t.-evoked e.p.s.p.s in type 1 g.c.l. cells. These observations are in good agreement with the hypothesis that l.o.t.-evoked i.p.s.p.s are mainly mediated by the dendrodendritic reciprocal synapses between mitral cell dendrites and peripheral processes of granule cells. 5. The results are discussed in relation to the inhibitory mechanisms controlling mitral cell activity in the olfactory bulb.
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PMID:Activation and inhibition of olfactory bulb neurones by anterior commissure volleys in the rabbit. 67 64

Serial thin sections of the mouse olfactory bulb from the fourteenth day of gestation (E14) to postnatal to 44 (P44) have been examined in order to study morphogenesis of individual synaptic junctions. At the initiation of synapse formation structures are found that resemble postsynaptic densities but are facing extracellular space or unmodified processes. Transition forms between these isolated postsynaptic densities and undoubted synapses have been found. These observations as well as quantitative studies support the hypothesis that isolated postsynaptic densities can form independently and be converted to synapses when a presynaptic specialization develops opposite them. Detailed studies of olfactory axodendritic synaptogenesis throughout the entire developmental period suggests strongly that these asymmetrical synapses pass through an immature symmetrical phase: (1) symmetrical olfactory axodendritic synapses are found in significantly higher concentration on axonal and dendritic growth cones than on more common processes; (2) the number of symmetrical synapses is correlated with the rate of formation of new synapses determined previously. The time for a recognizable symmetrical synapse to be transformed into a recognizable asymmetrical one has been calculated to be 9--10 hours. A scheme of synapse formation in the CNS has been proposed in which a post-synaptic structure forms independently followed by aggregation of pre-existing presynaptic components into a presynaptic specialization. Different morphogenetic sequences of synapse formation from region to region are attributed simply to different relative rates in the development of the postsynaptic density and the presynaptic specialization.
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PMID:Synapse formation in the mouse olfactory bulb. II. Morphogenesis. 95 64

The habenular nuclei in the diencephalon of the frog, Rana pipiens, are asymmetrical structures: two discrete cell groups develop on the left side (as medial and lateral nuclei), while a single nucleus is formed on the right side. Experimental animals were subjected to bilateral removal of the olfactory pits at an early embryonic stage, and were maintained with normal control animals until metamorphosis was complete. The length, relative volume and cell number for each of the three nuclei were determined in the control and experimental animals at regular intervals during larval development. In the control animals, the left medial nucleus developed similarly to the right nucleus spatially and temporally; however, the left lateral nucleus was significantly different in its development in the three parameters measured. In the experimental animals the left medial and the right habenular nuclei were alone affected by the removal of the olfactory pits. The results provide experimental evidence that the right and left medial, but not the left lateral, habenular nuclei are centers receiving afferent olfactory fibers.
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PMID:The effect of ablation of the olfactory pits on the development of the habenular nuclei in Rana pipiens. 108 87

The authors describe three pathological cases of akinetic mutism with, as a common basic lesion, bilateral infarction of the cingulate gyrus secondary to aneurysm of the anterior communicating artery (case n degrees 1), to a huge olfactory meningioma (case n degrees 2), both operated on, and to atheromatous occlusion of the anterior cerebral arterial system (case n degrees 3). These three cases enable a variety of "anterior and waking" akinetic mutism to be described which is unusual enough to be compared with other mesencephalic and diencephalic aspects of this syndrome. It is in fact an akinetic mutism characterized by: a certain dissociation in its non-response to various stimuli, a particularly marked appearance of wakefulness when day-time alertness is considered, conservation of the waking-sleeping rhythm, perception and reaction unpredictable and paradoxical in both degree and quality, complete absence of any spontaneous verbal communication in contrast to relative break-down of solicited communication which is infrequent, uncertain and unresponsive to the usual methods of stimulation, without any possibility of a code. In addition, there is a remarkable mimic and segmental general akinesia, resistant to the usual nociceptive stimuli, but sensitive to slight excitation of the manual and oral zones. Besides this special akinetic mutism, there are variously systematised signs, mostly asymmetrical, indicating lesion of the cortico-sub-cortical frontal structures bordering on the gyrus cinguli. This unusual behaviour pattern corresponds in these three cases to extensive anterior bilateral ischemic lesions of the cingulate gyrus regularly associated with bilateral infarctions confined to the medial aspect of F1 in the superficial territory of the two anterior cerebral arteries, to possible neurosurgical changes (ablation of the right frontal pole) and to compressive or ischaemic lesions of the gyrus rectus. These exclusively cortico-sub-cortical associated lesions are in contrast with the remarkably intact caudate nuclei, the pallidal, thalamic, hypothalamic and septal formations and the anterior pillars of the fornix. These findings compared with the results of experimental research carried out by M. Kennard, help, if help is needed, to resolve the apparent contradictions between the effects of therapeutic cingulectomies or cingulotomies and the scanty pathological data already available in cerebral vascular pathology.
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PMID:[Akinetic mutism and bicingular softening. 3 anatomo-clinical cases]. 113 49

Transplant-to-host axon projection and synapse formation from the olfactory bulb (OB) transplant to the host cerebellum were studied using the mouse allelic form of Thy-1 (AKR strain of Thy-1.1 was used as host and BALB/c strain of Thy-1.2 as graft). Thy-1.2 immunohistochemical and ultrastructural examination showed that numerous OB axons elongate into the cerebellar granular layer and form asymmetrical synapses there with dendrites of host origin (perhaps of the host granule neuron). Factors which support this mismatched synapse formation are discussed.
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PMID:Axons from the olfactory bulb transplanted into the cerebellum form synapses with dendrites in the granular layer, as demonstrated by mouse allelic form of Thy-1 and electron microscopy. 132 55

Projections from the basolateral nucleus of the amygdala (BLA) to the frontal cortex and the striatum were studied by using Phaseolus vulgaris-leucoagglutinin (PHA-L) anterograde tracing technique in the rat. PHA-L injections into the rostral part of the BLA resulted in a dense labeling of fibers with boutons in the dorsal bank of the rhinal fissure and in the lateral and the medial agranular cortex. PHA-L injections into the caudal part of the BLA produced a dense labeling of fibers in the medial surface of the frontal cortex. In most of the cortical regions, labeled fibers were predominantly distributed in two bands: one in the deep part of layers I and II and the other, heavier band, in layers V and VI. PHA-L injections into the rostral BLA resulted in a dense labeling of fibers with boutons in the olfactory tubercle, the rostral and caudolateral portion of the nucleus accumbens, and a large region of the caudate-putamen. The labeled area of the caudate-putamen included the rostroventral area, the central area, and the area caudal to the anterior commissure and dorsal and lateral to the globus pallidus. PHA-L injections into the caudal BLA produced fiber labeling in the most rostromedial area of the caudate-putamen facing the lateral ventricle, the medial portion of the nucleus accumbens, and the lateral septum. In the rostroventral striatum, PHA-L-labeled fibers selectively innervated the matrix compartment that contains abundant somatostatin-immunoreactive fibers. Compartmental segregation was less clear in the caudodorsolateral caudate-putamen and in the nucleus accumbens. Electron microscopy revealed that PHA-L-labeled boutons in the striatum contained abundant, small, round vesicles. These boutons formed asymmetrical synapses with dendritic spines of striatal neurons.
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PMID:Amygdaloid projections to the frontal cortex and the striatum in the rat. 169 28

There are several anatomically and functionally distinct retinofugal pathways, one of which is the retinohypothalamic tract (RHT). In this study, horseradish peroxidase conjugated to cholera toxin (CT-HRP), a sensitive neural tracer, was employed to describe the RHT in the female albino rat. Following uniocular injection of CT-HRP, both medial and lateral components of the RHT were evident. The medial component swept caudally into and through the suprachiasmatic nucleus (SCN) and dorsally to the subparaventricular zone. Terminal label was seen in the medial preoptic region, peri-SCN area, retrochiasmatic area, periventricular nucleus, anterior and central parts of the anterior hypothalamic area, and the subparaventricular zone. In contrast to the more focused and symmetrical medial component, the lateral component was diffuse with light terminal label in the lateral preoptic region, olfactory tubercle, lateral hypothalamus, supraoptic nucleus, and medial and posteroventral medial amygdaloid nuclei. The striking exception to this diffuse pattern of the lateral component was an extremely dense columnar terminal field over the dorsal border of the supraoptic nucleus. Whereas the intensity of label in terminal fields of the medial component was often similar on the sides ipsilateral and contralateral to the injection, the lateral component was consistently asymmetrical with greater labeling on the side contralateral to the injection. In addition, a light projection arrived at several thalamic nuclei by returning toward the thalamus from the tectal or pretectal areas via stria medullaris, and thus was not a part of the RHT. Implications for circadian as well as noncircadian photobiologic effects are discussed.
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PMID:Retinohypothalamic tract in the female albino rat: a study using horseradish peroxidase conjugated to cholera toxin. 171 Oct 60

The morphological characteristics of the synaptic contacts in the ruff of the cichlid fish Hemichromis bimaculatus were studies using the combined Golgi-electron microscope technique. Ruffed cells were located in the glomerular and plexiform layers and exhibited a pyriform or round cell body and numerous thin dendritic branches that were highly ramified. Four different segments could be distinguished on the initial portion of the axon (IP) according to the number and density of protrusions. These protrusions or lateral appendages are highly interdigitated, forming a characteristic synaptic field: the ruff. The ruff displayed a very high number of synapses with terminals showing a varied morphology. Protrusions of the ruff were both presynaptic and postsynaptic, taking also part in reciprocal pairs of synapses. Synapses from the ruff to the adjacent prolongation are asymmetrical, the prolongation to protrusion synapses being symmetrical. The axonal shaft participates in fewer synaptic contacts. Boutons contacting with one protrusion can synapt with other one, and can also receive an asymmetric synapse from another terminal, forming a serial synapse. This constitutes the most complex synaptic system observed in the glomerular layer of the olfactory bulb in any vertebrate. The synaptology of the ruffed cell IP is compared with previous reports on other species, with the teleostean mitral cells and with the IP of higher vertebrates neurons, the ruffed cells showing a completely different synaptic pattern.
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PMID:Ruffed cells in the olfactory bulb of freshwater teleosts. II. A Golgi/EM study of the ruff. 172 80


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