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At least 19 recordsLinked to original sources
PubMed1979

[Nystagmus giratoire and optic nerve hypoplasia in combination with absence of the septum pellucidum (author's transl)].

Septo-optical dysplasia and Optic nerve hypoplasia often are combined with pendular nystagmus in the horizontal, vertikal or rotatory direction. Our patient, 26 year old, showing discret neurological symptoms, added the nystagmus giratoire, perhaps similar to see-saw-nystagmus: Vision was about 0.2. Nystagmus and the whole state did not change within 6 years. The nystagmus was influenced by drugs. There was found also an aplasia of the fovea zentralis. Pneumencephalography revealed in the midline a dilatated single ventricle; the septum pellucidum was absent. Te X-rays of the atlantooccipital axis showed a foramen arcuale atlantis.

Adult↗
PubMed1978

Septo-optic dysplasia (de Morsier syndrome).

A 12-year-old girl and a 30-year-old woman had bilateral optic disk hypoplasia and bitemporal hemianopia. By using computed axial tomography on our patients, we demonstrated the absence of the septum pellucidum, which confirmed the diagnosis of septo-optic dysplasia, or the de Morsier syndrome.

Adult↗
PubMed1978

A case of septo-optic dysplasia.

A child was reported here who has the hypoplastic optic nerve, absent septum pellucidum and endocrinological disorders. Growth hormone deficiency, antidiuretic hormone deficiency and mild hypothyroidism were observed. He has been treated with thyroid hormone and DDAVP.

Child, Preschool↗
PubMed1979

CT of septo-optic dysplasia.

Two girls, aged 7 1/2 and 12 years, clinically suspect for septo-optic dysplasia, were investigated by computed tomography (CT). The clinical picture in both cases associated blindness with hypoplasia of both optic discs, and short stature with growth hormone deficiency. Diabetes insipidus was also present in one case. CT demonstrated agenesis of the septum pellucidum and thin optic nerves. In the case with diabetes insipidus the pituitary stalk was enlarged. It is shown that CT accurately delinerates the altered anatomy of septo-optic dysplasia. CT is recommended rather than pneumoencephalography as the definitive neuroradiologic investigation of these patients.

Abnormalities, Multiple↗
PubMed1977

Computed tomography of extracerebral hematoma.

The appearance on C.T. of 30 extracerebral hematomas is described. Acute subdural hematomas were seen as bandlike lesions with markedly increased, homogenous density. Epidural hematomas demonstrated a high density and a biconvex, lenticular shape. During the process of liquefaction the density decreases and three hematomas appeared as isodense lesions. The majority of chronic subdural hematomas presented a mildly to moderately decreased, nonhomogenous density, the clearly identifiable inner wall of the lesion being either convex or concave. Subdural hygromas showed a homogeneous, markedly decreased density. Almost all the hematomas caused compression of the homolateral lateral ventricle and displacement of midline structures, particularly of the septum pellucidum. In 60% of the hematomas a dilatation of the contralateral lateral ventricle, predominantly of the posterior part was seen. Acute hematomas presented oedema in varying degrees, in chronic hematomas oedema was usually absent. In the original interpretation extracerebral hematomas were recognized as a lesion on C.T. in 97% (1 false negative result), in 90%, the lesion was correctly diagnosed as an extracerebral hematoma (1 false negative and 2 incorrect). The series contained one false positive C.T. scan and 2 intracerebral hematomas were interpreted incorrectly as subdural hematomas. The review C.T. diagnosis proved to be correct in 100%. C.T. and angiography appeared to have about the same diagnostic accuracy. However, C.T. is a non invasive investigation and it provides valuable additional information with regard to all the intracranial contents. Therefore C.T. should be the method of first choice in the diagnosis of extracerebral hematomas.

Adult↗
PubMed1979

Hydrocephalus and amenorrhea.

A 25-year-old woman was seen for the complaint of secondary amenorrhea. Skull roentgenograms revealed a markedly enlarged sella turcica. Studies of pituitary and hypothalamic function including prolactin were normal. A pneumoencephalogram revealed dilated ventricles and a mass in the septum pellucidum and hypothalamus. Partial removal of this hypothalamic astrocytoma and placement of an interventricular shunt resulted in the return of menses. Recurrent obstruction a few months later resulted in headache, disorientation, and amenorrhea. A shunt was placed again, resulting in clearing of symptoms and a reestablishment of normal menstrual cyclicity. It appears that the occurrence of increased intracranial pressure rather than the hypothalamic tumor caused the amenorrhea.

Adult↗
PubMed1977

Hippocampal electrical activity during waking behaviour and sleep: analyses using centrally acting drugs.

Rhythmical slow activity (RSA) occurs in the hippocampus under many conditions including waking behaviour, active sleep and surgical anaesthesia. Under all these conditions RSA, apparently, is produced by the coupled operation of CA1 and dentate gyrus generators. Two ascending brainstem systems appear capable of initiating activity in these coupled generators. One system, ascending via the diagonal band and medial septal nucleus, may contain cholinergic synapses since it is blocked by atropine and stimulated by eserine. The RSA produced by this system usually has a frequency of 4--7 Hz and can occur during total immobility during the waking state, active sleep or anaesthesia. A second ascending system produces RSA of higher frequency (usually 7--12 Hz) and is active during waking if, and only if, movements such as walking occur. During active sleep this system is active only during phasic muscular twitches. Anaesthetics (ether, urethane) and morphine abolish activity in this second system but it is resistant to atropinic and nicotinic drugs. Amphetamine stimulates, and major tranquillizers depress the atropine-resistant system but these drugs do not abolish its normal relation to behaviour. Neocortical activity appears to be controlled by two ascending systems which parallel closely those ascending to the hippocampus.

Anesthesia, General↗
PubMed1977

The role of the septo-hippocampal system and its noradrenergic afferents in behavioural responses to none-reward.

Our experiments were designed with two purposes: (i) to examine the effects on one behaviour of differing interventions in the septo-hippocampal system; (ii) to compare these effects with those of minor tranquillizers. The behaviour studied (in rats) is extinction in the alley after continuous (CRF) or partial (PRF) reinforcement. Minor tranquillizers and large septal lesions produce three effects: (1) resistance to extinction is increased after CRF; (2) resistance to extinction is decreased after PRF; (3) the partial reinforcement extinction effect (PREE) is abolished. Small septal lesions fractionate this syndrome: either effect (1) or an actual increase in the size of the PREE is produced by medial septal lesions abolishing hippocampal theta; effects (2) and (3), but not (1), are produced by lateral septal lesions sparing theta. Dorso-medial fornix section, abolishing theta, reproduces the effects of medial septal lesions. Fimbrial section, sparing theta, reproduces some of the effects of lateral septal lesions. Minor tranquillizers produce a rise in the threshold for septal driving of hippocampal theta specifically at 7.7 Hz. This effect is reproduced by blockade of noradrenergic transmission or destruction of the dorsal noradrenergic bundle with 6-hydroxydopamine. This lesion reproduces all three behavioural changes listed above. These results suggest a model for the role of the septo-hippocampal system and its noradrenergic inputs in the PREE. This model is compared with other approaches to the septo-hippocampal system.

Afferent Pathways↗
PubMed1977

The function of septo-hippocampal connections in spatially organized behaviour.

The role of septo-hippocampal connections in spatial behaviour is examined in lesion and stimulation experiments in rats. Destruction of septo-hippocampal connections produces a severe and enduring deficit in the ability to perform a spatial memory task. Furthermore, crossed unilateral lesions of the entorhinal area and fimbria-fornix produce the same deficit as bilateral lesions in either the entorhinal area or the fimbria-fornix, as predicted from a disconnection analysis of hippocampal lesions. Evidence also suggests that septo-hippocampal damage produces a greater deficit in spatial behaviours when a flexible response is required than when a consistent response is required, although this difference is a relative one rather than an absolute one. Finally, disruptive stimulation of the hippocampus while rats are performing a spatial memory task produces retrograde amnesia but not proactive interference. Taken together, these data indicate an important role of the septo-hippocampal system in spatial behaviour, and in the maintenance of spatial memories.

Animals↗
PubMed1977

Multivariate analysis of the septal syndrome.

Since recent reviews of the behavioural effects of septal lesions agree that more than one explanatory concept is required, a multivariate analysis of the septal syndrome has been made. A total of 127 rats have been tested 73 with septal lesions and 54 controls. The rats were tested in a standard test battery consisting of a residential maze, spontaneous alternation, spatial learning, approach/avoidance conflict and one-way active avoidance. Factor analyses reveal a complex change in the factor structure after septal lesions. None of the previous explanations of septal functions receives unequivocal support. The findings do not exclude the possibility that septal lesions interfere with a few general behaviour mechanisms or perhaps only one. However, if so, this factor does not explain as much of the variance as expected. Situational or test-dependent factors play a greater role in the variance. This is interpreted as an indication of insufficiency in the theoretical structure, or in conventional test designs.

Animals↗
PubMed1977

Anatomical and functional aspects of the septo-hippocampal projections.

The origins, distribution, and cellular targets of the septo-hippocampal projections are reviewed. It appears that the distribution of acetylcholinesterase-positive neurons in the medial septum and diagonal bands and those cells labelled after injections of horseradish peroxidase into the hippocampus coincide; however, the possibility of a non-acetylcholinesterase septal projection remains. Good agreement is found between the distribution of hippocampal acetylcholinesterase and the patterning of silver grains after injection of [3H]leucine into the medial septum. A major target of septal efferents to the hippocampus is the interneuron population; the possibility of septal mediation of intrahippocampal circuitry via this anatomical arrangement is discussed.

Acetylcholinesterase↗
PubMed1977

The anatomical organization of septo-hippocampal projections.

Since the time of Elliot Smith (1910) it has been recognized that the septal complex occupies a pivotal position within the mammalian telencephalon, being strategically placed between the hippocampal formation on the one hand and the basal forebrain and diencephalon on the other. However, it is only in the last few years that the detailed interrelationships between the different nuclear groups within the septum and the various subfields of the hippocampus have been studied. We have recently re-examined the connections of both the septum and the hippocampal formation using the techniques based on the anterograde transport of isotopically labelled proteins and the retrograde transport of the enzyme marker, horseradish peroxidase. Our findings may be summarized as follows. Field CA1 of Ammon's horn and the adjoining subiculum project through the fimbria and pre-commissural fornix upon the lateral septal nucleus of the same side in a topographically ordered manner. Field CA3, on the other hand, projects bilaterally upon the lateral septum. The lateral septal nucleus in turn, projects partly upon the medial septal nucleus and nucleus of the diagonal band, and partly to the lateral hypothalamus and the mamillary complex. The medial septal-diagonal band complex projects back, through the fimbria and dorsal fornix, to fields CA3 and CA4 of the hippocampus, to the dentate gyrus, to the subicular complex, and to the entorhinal area. The subicular complex projects through the post-commissural fornix to the anterior thalamic group, the mamillary complex, and the ventromedial and arcuate nuclei of the hypothalamus. Ammon's horn and the subiculum also project to the posterior septal nuclei (triangular and septofimbrial), which in turn send their output to the habenular and interpeduncular nuclei. The significance of these projections is analysed in a review of the major known afferent and efferent connections of the septum and hippocampus, and the cell groups to which they project directly.

Amygdala↗
PubMed1977

Localization of putative transmitters in the hippocampal formation: with a note on the connections to septum and hypothalamus.

Biochemical assays on microdissected samples, denervation studies, subcellular fractionation, and light and electron microscopic autoradiography of high affinity uptake have been performed to study the cellular localization of transmitter candidates in the rat hippocampal formation. High affinity uptake of glutamate and aspartate is localized in the terminals of several excitatory systems, such as the entorhino-dentate fibres (perforant path), mossy fibres (from granular cells) and pyramidal cell axons. Thus, in stratum radiatum and oriens of CA1, 85% of glutamate and asparate uptake and 40% of glutamate and aspartate content are lost after lesions of ipsilateral plus commissural fibres from CA3/CA4. Hippocampal efferents also take up aspartate and glutamate, since these activities are heavily reduced in the lateral septum and mamillary bodies after transection of fimbria and the dorsal fornix. The synthesis (by glutamic acid decarboxylase), content and high affinity uptake of gamma-aminobutyrate (GABA) are not reduced after lesions of these or other projection fibre systems. A localization in intrinsic neurons is confirmed by a selective loss of glutamic acid decarboxylase after local injections of kainic acid. Peak concentrations of the enzyme occur near the pyramidal and granular cell bodies, corresponding to the site of the inhibitory basket cell terminals, and in the outer parts of the molecular layers. Some 85% of glutamic acid decarboxylase is situated in 'nerve ending particles'. Acetylcholine synthesis (by choline acetyltransferase) disappears after lesions of septo-hippocampal fibres. Since 80% of the hippocampal choline acetyltransferase is in 'nerve ending particles', the characteristic topographical distribution of this enzyme should reflect the distribution of cholinergic septo-hippocampal afferents. Serotonin, noradrenaline, dopamine and histamine are located/synthesized in afferent fibre systems. Some monoamine-containing afferents to the hippocampal formation pass via the septal area, others via the amygdala. The hippocampal formation also contains nerve elements reacting with antibodies against neuroactive peptides, such as enkephalin, substance P, somatostatin and gastrin/cholecystokinin.

Acetylcholine↗
PubMed1977

Long-lasting facilitation of synaptic transmission.

After tetanization of several hippocampal pathways (10--50 Hz for 5--15 seconds) there is an increased synaptic transmission of long duration (long-lasting facilitation). The present investigation was undertaken on isolated hippocampal slices to study the mechanism of the effect. The transverse hippocampal slice preparation in vitro allows the simultaneous testing of several afferent fibre systems on the same cell or population of cells. Tetanization of one group of afferent fibres to CA1 pyramids was followed by a long-lasting increase of synaptic transmission along the same fibres, whereas a control input line gave unchanged responses. Using the presynaptic volley as an indicator of the number of afferent impulses, the increased synaptic transmission appeared as an increased excitatory postsynaptic potential (EPSP), increased amplitude and reduced latency of the population spike, and an increased probability of firing of single units. Intracellular recording showed increased EPSPs to afferents of the tetanized line, but no lasting change in membrane resistance or in the response to a depolarizing current pulse. Thus, the effect cannot be ascribed to a general postsynaptic excitability increase. The specific changes in the synaptic transmission may be due either to an increased amount of liberated transmitter or to a local postsynaptic change near the tetanized synapses.

Afferent Pathways↗
PubMed1977

Cholinergic mechanisms and short-term potentiation.

Acutely prepared rabbits were used to study, electrophysiologically, tetanic and post-tetanic potentiation of the pathway from the medial septal region to hippocampal field CA1. It was found that tetanic potentiation, evoked by short stimulus trains, was maximal at 6--8 Hz. Responses recovered from post-tetanic potentiation in 5--35 seconds. Acetylcholine, physostigmine, and cyclic GMP each had an excitatory effect on pyramidal cell responses when applied in stratum radiatum. The time course studies showed that these effects outlasted the duration of the injection current by many minutes. Phosphodiesterase inhibitors (e.g., isobutyl methyl xanthine) prolonged the time course of recovery with test responses which were post-tetanically potentiated. K+, on the other hand, selectively enhanced tetanic potentiation. It is suggested, with respect to the potentiation phenomena, that K+ acted primarily presynaptically to facilitate transmitter release, whereas cyclic GMP acted primarily postsynaptically for the enhancement of pyramidal cell excitability.

Acetylcholine↗