Emergence of preconfigured and plastic time-compressed sequences in early postnatal development.

When and how hippocampal neuronal ensembles first organize to support encoding and consolidation of memory episodes, a critical cognitive function of the brain, are unknown. We recorded electrophysiological activity from large ensembles of hippocampal neurons starting on the first day after eye opening as naïve rats navigated linear environments and slept. We found a gradual age-dependent, navigational experience-independent assembly of preconfigured trajectory-like sequences from persistent, location-depicting ensembles during postnatal week 3. Adult-like compressed binding of adjacent locations into trajectories during navigation and their navigational experience-dependent replay during sleep emerged in concert from spontaneous preconfigured sequences only during early postnatal week 4. Our findings reveal ethologically relevant distinct phases in the development of hippocampal preconfigured and experience-dependent sequential patterns thought to be important for episodic memory formation.

Macro- and microanatomic factors involved in the flat bones morphogenesis from the craniofacial system.

The authors present a study both upon eight crania of dead born fetuses having the vertex-coccis distance between 25-29 cm and a human embryocephalic extremity of 18 cm. The crania were examined in the lateral, vertical, frontal, occipital, basal norms. Sagittal sections were performed upon the embryo, and then those sections were microscopically examined after HE staining. We concluded that the cranial arch bones morphogenesis and the facial complex is a long-time development process, which initially started during the early embryogenesis, and it is completed as an adult. Determining factors of the flat bones osteogenesis are the following: vascular, muscle, extracell (mesenchyma) and neuronal factors (rhombencephalon presence).

Contributions to the micro-anatomical evaluation of the ratio between the muscular tunic structures of the oesophagus. Biomechanical, anatomic and clinical implications.

The aim of our research is to make a microanatomical evaluation of the ratios of the structural elements of the oesophagus muscular tunic and suggest a new perspective in the general knowledge about this tubular organ. The visualisation of the structural elements was done using classical microanatomical methods Hematoxylin-Eosin for general orientation, Van Gieson for picrofuxinophile collagen fibers and Gömöri for reticuline fibers. The neurofilaments were identified using silver impregnation on Cajal block. The examination of the sections was made with the Nikon Eclipse 600 photomicroscope. The images were taken and processed using a computer with LuciaNet licensed Microsoft. The co-existence in the architecture of the oesophagus of two microcinematic systems structurally divergent, but functionally convergent represents microanatomical arguments for the nomination of a new type of muscles--the oesophageal muscle--anatomo-functionally different from the skeletal striate muscle, from the smooth visceral muscle, from the cardiac muscle or from the embryonic type muscle of the excitoconductor system. The extra cellular matrix of the muscular tunic of the oesophagus contributes to the organization of the endo- and peri-misium, as well as to the three structures involved in the biomechanics of the oesophageal muscle: the connective-vascular septa, the microtendons that have in their structure receptors of the peristaltic reflex and, finally, the lamina propria myenterica strewed with numerous neuronal structures. The co-existence of the stereo-distribution of the monostructured fascicles (skeletal muscular fibers or smooth muscular cells) with bistructured fascicles (skeletal-smooth) gives the oesophagus a heterogeneous architecture. Lamina propria myenterica, which realizes the border between the circular and longitudinal strata, contains two neuronal structures of its own, but anatomically inserted the neural myenteric plexus which is equivalent to the Auerbach plexus and the neuroganglion of the myenteric plexus, equivalent to the visceral neuroganglion Cajal-Retzius.

Ectopic osteogenesis in the rectus sheath.

Although was published many cases of ectopic osteogenesis of traumatic, neurogenic cause or hereditable form, the etiology of ectopic osteogenesis remaining unknown. We present ectopic osteogenesis in the rectus abdominal sheath. The study material was represented from fragments of ectopic bones discovered in rectus sheath of four patients suffering iterative surgical abdominal interventions. The pieces of ectopic bone were decalcified and then were made to the standard techniques (paraffin inclusion, general techniques dyeing). The process of ectopic osteogenesis was analyzed through microscopically study to seriated sections of discovered piece, finding the presence of the hematopoesis foci. We conclude that is important identifying and characterizing the osteoinductor agents because these allowed the study of osteogenesis to the cellular level and make an estimation of the abnormally bone developing mechanisms. A possible osteoinductor factor has been considerate the non-absorbable wound closure material.

Interactions between hippocampus and medial septum during sharp waves and theta oscillation in the behaving rat.

The medial septal region and the hippocampus are connected reciprocally via GABAergic neurons, but the physiological role of this loop is still not well understood. In an attempt to reveal the physiological effects of the hippocamposeptal GABAergic projection, we cross-correlated hippocampal sharp wave (SPW) ripples or theta activity and extracellular units recorded in the medial septum and diagonal band of Broca (MSDB) in freely moving rats. The majority of single MSDB cells (60%) were significantly suppressed during SPWs. Most cells inhibited during SPW (80%) fired rhythmically and phase-locked to the negative peak of the CA1 pyramidal layer theta waves. Because both SPW and the negative peak of local theta waves correspond to the maximum discharge probability of CA1 pyramidal cells and interneuron classes, the findings indicate that the activity of medial septal neurons can be negatively (during SPW) or positively (during theta waves) correlated with the activity of hippocampal interneurons. We hypothesize that the functional coupling between medial septal neurons and hippocampal interneurons varies in a state-dependent manner.

Inhibitory effect of disodium edetate on gastric secretion.

Disodium edetate (ethylenediaminetetraacetic acid, disodium salt; disodic EDTA), 3 g, was given, via an intravenous normal saline drip of 30 min, to 25 patients in order to assess a benefit for anaesthesia practice. A significant reduction of both volume and acidity of the gastric secretion was found in all the 10 patients with peptic ulcer having received the drug. The peak of the change was 1 h after administration. In other 10 non-ulcer patients undergoing orthopaedic surgeries under epidural anaesthesia with lidocaine 2%, 5 mg kg-1, pH of the gastric juice unanimously rose, from 2.24 +/- 0.28 to 4.10 +/- 0.21 1 h after EDTA with a P derived from paired difference analysis of less than 0.001. A similar group of patients receiving only normal saline showed no important changes in pH (from 2.37 +/- 0.24 to 2.34 +/- 0.19). The pH of the fundic surface, measured directly under fiberscopic control in further 5 patients suffering from peptic ulcer, was found also to rise from 1.84 +/- 0.21 to 4.62 +/- 0.34 1 h after EDTA, P less than 0.001. Total and ionized calcium changed unsignificantly. Disodic EDTA in the dose and manner used in this study showed no clinical side-effects. The constant and obvious effect of inhibition of the gastric secretion as well as the dynamics of such an action recommend disodic EDTA to be tried in reducing the aspiration pneumonia morbidity.

[Morphology of the ciliary ganglion (author's transl)]. / Aspects morphologiques du ganglion ciliaire.

Microscopic examination of the ciliary ganglion shows the presence of large peripheral and moderately-sized central neurones. The appearance of the intraganglionic neurones suggests that they are of the parasympathetic type, sensory fibres and sympathetic fibre bundles passing through the ganglion without synapses. Afferent fibres are long and thin and have no collateral endings, while efferent fibres are short and thick. Afferent nerve fibres have either a very thin or no myelin sheath, whereas post-ganglionic fibres are richly myelinated.