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Biochemical, hormonal, and behavioural aspects of the effects of prenatal treatment (foetal days 18 and 19) with 6-hydroxydopa (2 × 40 mg/kg) and DSP 4 (2 × 20 mg/kg) have been studied in the rat. The results of the catecholamine assays suggest that the 6-hydroxydopa treatment produced a transient decrease of noradrenaline concentration in the cerebral cortex, and a long-lasting decrease in the cerebellum, whereas DSP 4 produced a long-lasting decrease in the cerebral cortex and a tendency towards increase in the cerebellum. Assays of adrenocorticotropic hormone and corticosterone indicated a general tendency towards increase in base line as well as in moderate stress situations. The results of behavioural tests indicated hyperactivity and/or hyperreactivity, but not restlessness, and partly supranormal sensorimotor performances., (Copyright © 1985. Published by Elsevier Ltd.)

In a controlled clinical trial, the efficacy of an intravenous combination of cimetidine and pirenzepine (group A: 62 patients) was compared with that of an intragastric administration of a magnesium-aluminium-hydroxide concentrate (group B: 58 patients) in preventing visible and occult upper gastrointestinal tract bleeding in intensive-care patients. It was found that both forms of therapy had the same favourable effect on the extent and incidence rate of visible and occult gastric bleeding. The antacid was more effective than the cimetidine-pirenzepine combination in raising the pH level to 4 or higher (P less than 0.05). Intensive-care patients should, therefore, be treated with the antacid whenever possible, since it is equally effective as the cimetidine-pirenzepine combination in preventing bleeding from the upper gastrointestinal tract, whereas it is superior in elevating the gastric pH. Besides, the use of the antacid is also less costly.

The possible influence of noradrenaline (NA) upon cell differentiation has been studied by comparing NA-supplemented cultures of foetal pallial cells with control cultures grown in normal medium. Two days after plating, the cultures were processed for immunocytochemical detection of either an adhesion molecule and marker of early stages of neuronal differentiation (L1) or a marker expressed at relatively late stages (gamma-enolase). In both cases, the NA supplement reduced the expression of the antigen. The effects were more clear-cut for the late than for the early marker. In conclusion, the NA supplement to the culture medium, in our model, seemed to have a 'differentiation regulating' rather than a 'neurotrophic' function sensu stricto. It remains to be clarified, however, to which extent this finding can be generalized to in vivo situations.

Early cortical neurogenesis and synaptogenesis are discussed with reference to observations made in fetal and postnatal rat temporal cortex. Thymidine autoradiography was used to determine the time of origin of cortical neurons, particularly of layer I. Earliest neurons--CRs--form between FD 12 and 15, whereas the period of maximal formation of layer I neurons other than CRs is situated between FD 17 and FD 19. Neurons destined for the deepest part of layer VI begin to form at FD 13. Both types of early-forming neurons develop synaptic contacts by FD 16. From this stage onwards, the temporal cortex taken as a whole continuously contains synaptic contacts. However, a more detailed analysis shows that some at least of the early formed synapses are transitory: for example, the CRs, which receive dendritic synapses on FD 16 and somatic synapses on FD 17, apparently lose most--if not all--of these contacts towards the end of fetal life. Whereas CRs develop an important protein producing equipment during the neonatal period, younger neurons located in the same (first) layer form dendritic, somatic and somatofugal synapses.

The onset of synaptogenesis was studied in the temporal cortex of rat fetuses whose age ranged between 15 and 19 days of gestation. First synapses were found at a surprisingly early stage of cortical development: on day 16. These contacts showed relatively few vesicles and very inconspicuous membrane-thickenings. They were located in the marginal layer, above as well as below the narrow band formed by the newly arrived first neuroblasts of the prospective corticle plate. The postsynaptic structures were probably dendrites of the horizontally or obliquely orientated neurons scattered throughout the marginal layer (such neurons were seen even within the cell-dense band). On day 17, the cortical plate separated the differentiated cells definitely into a superficial and a deep population. As on the following days, synapses were found above and below the cortical plate but not within it. In addition to contacts showing the same features as those described on day 16, there were already synapses with numerous vesicles and clearly asymmetric membrane thickenings. On days 18 and 19 the borders of the cortical plate became more clear-cut. The well-differentiated neurons situated above and below this plate could now be identified as Retzius-Cajal cells of the prospective molecular layer and as polymorphous cells of the layer VI b respectively. The presence of axo-somatic contacts on these neurons provided direct evidence that both cell types are targets for synapses. Desmosome-like junctions were found even in the youngest fetuses studied. Their roughly symmetric membrane thickenings were clearly more conspicious than those of earliest synapses. Desmosome-like junctions occurred very frequently between structures which subsequently were never seen to become synaptically linked. During the entire period studied, numerous coated vesicles fused with cell membranes were noted. Such "open" vesicles were seen on neurons (sometimes in the immediate vicinity of synapses) but also on non-nervous, extracortical as well as intracortical structures. Thus there does not seem to be a specific relationship between desmosome-like junctions and coated vesicles on the one hand and synapse formation on the other.

We report on a case of transient neurogenic dysfunction of the urinary bladder caused by herpes genitalis in a renal transplant patient. The patient noticed a slow urinary stream 3 days after the vesicular stage of the herpes genitalis. After 9 days complete urinary retention and loss of sensation developed, necessitating the insertion of suprapubic tube. Symptoms and residual urine spontaneously disappeared after 20 days. After removal of the suprapubic tube the patient could empty his bladder completely with good stream. 45 cases of this kind have been described in the literature. the cause is a sacral meningo-radiculitis with herpes simplex virus leading to a transient neuromotoric paralysis of the bladder.

Newborn rats received an intracisternal injection of 6-hydroxydopamine (100 micrograms) within 16 h after birth. Treatment effects upon noradrenaline uptake (with or without desmethylimipramine pre-incubation), endogenous noradrenaline, dopamine, and serotonin were biochemically assayed. Noradrenaline uptake and endogenous noradrenaline content were permanently reduced to less than 5% of control values. Reduction of endogenous dopamine content was less marked: at day 60, values were about 40% of controls. Serotonin content remained unaffected. Cell density countings in postnatal day 15 temporal cortex revealed an about 16% reduction in layers II and III of treated animals. These modifications of cortical geometry were discussed with reference to measurements of cortical thickness and ultrastructural observations on postnatal days 2, 5 and 15. Both supranormal involution and growth processes might result from the neurotoxin treatment. Whereas some of the degeneration processes might be due o general cytotoxic effects, this is less likely for the supranormal growth processes.

GM1 gangliosides were added to the medium of cultured raphe neurons enriched in the serotonergic phenotype in order to study their influence on biochemical and morphological growth parameters of serotonergic neurons. After 2 days of culture in the presence of GM1, specific uptake of serotonin measured by scintillation counting exhibited a moderate but significant increase for a GM1 concentration of 5 X 10(-8) M. Morphological parameters of 5-HT neurons were measured after immunocytochemical staining with specific serotonin antiserum, and digitalization of immunoreactive cells. Eight parameters were studied; for concentrations of 5 X 10(-8) and 10(-7) M of GM1, the absolute neuritic field area and the total length of the segments were significantly increased, whereas the number of neuritic segments, and their mean length were not modified. We conclude that GM1 ganglioside has a significant influence on the growth of serotonergic neurons. Moreover, electron microscopy showed, on treated cultures, a dramatic increase of the number of spicules all along the neuron's process, suggesting that GM1 could act by modifying the attachment of cells to their substrate. The possible molecular mechanisms of the action of GM1 are discussed.