The nerve fiber relationship with human arrector pili muscle cells: electron microscopy findings

Introduction. The arrector pili muscle has been the topic of several morphological studies for the different modality of association with the follicural unit, belonging to different body region ,employing reconstructed tridimensional images of serial histological sections. However up to date no ultrastructural study on the nerve fibers and their relationship with smooth muscle cells of the human muscle has been carried out.This is a very important issue to understand the anatomical bases supporting the neuroeffector mechanism modulating piloerection in normal and pathological condition. Materials and methods. Arm skin biopsies from children suspected for metabolic diseases but resulted negative to previous microscope observation, were reexamined for the presence of arrector pili smooth muscle cells under a transmission electron microscopy.(Philips,CM10). Results. The smooth muscle cells appear in a more or less narrow relationship with axonal varicosities of unmyelinated nerve fibers localized near muscle plasmalemma . At neuromuscular region the Schwann envelope appears partially or totally retracted from axonal varicosities and a variable intercellular gap (0,15-0,3 um) remained between axonal and plasmalemmal membrane. The plasmalemma shows irregular profile with frequently protruded tract ,with towards the axon.The axon contained vesicles different for diameter and content : large dense core vesicles ,small dense core, and clear vesicles. Conclusion. The ultrastructural morphology of arrector pili muscle myoneural junction ,appears quite different  from that of the skin epithelial and myoneural junctions ,according to the neuroeffector mechanism modulating piloerection

The innervation of human muscularis mucosae: an ultrastructural study

The muscularis mucosae, a thin band of smooth muscle located at the base of the gastrointestinal mucosa, has been the topic of very few studies .The muscularis mucosae might regulate the absorptive and secretory functions of the gut through movements of the mucosal surface (1).The autonomic innervation of this tissue is almost completely unknown.Therefore we have carried out an ultrastructural study on nerve fibers of muscolaris mucosae by using archived mucosal rectal biopsies of children of different age , examined in the past for the diagnosis of neurometabolic disease and resulted negative. Nerve fibers of muscularis mucosae were unmyelinated. They contain several axons with the characteristics of intervaricose tract completely or almost surrounded by Schwann cells . Other axons in the nerve fibers appear as varicosities partly covered with Schwann cell cytoplasm or naked, and filled with vesicles and mitochondria .The vesicles in the same varicosity appear pleomorphic: small clear-core vesicles , dense -core of small diameter or less often dense-core of larger type. The membrane of muscle cells often protruded toward the varicosity . No synaptic specialization was observed.With very low frequency we found varicosities in intimate contact with the plasmalemma . Pleomorphic vesicles inside the same varicosity suggest a complex neurotransmission based on the release of classical transmitter and cotransmitters.The physiological relevance of these nerves remains unclear. Strips of longitudinal muscularis mucosae isolated from the human, guinea pig and rat colon responded with concentration-dependent contractions to the application of several spasmogens (1). In the human muscularis mucosae, neurokinin A was most potent, followed by carbachol, prostaglandin F2 and acetylcholine. These findings suggest the possibility that the muscularis mucosae is innervated by excitatory cholinergic nerves (1).On the other hand in oesophagus exogenously applied adrenaline inhibited spontaneous activities of the muscularis mucosae motor activity. Adrenergic nerves might inhibit spontaneous motility via the inhibition of cholinergic neurotransmission. VIP- , NPY-, CGRP- and galanin-immunoreactive nerve fibers were observed in the human esophageal muscularis mucosae but their function remains unknown (2)

AN ABNORMALLY LONG STYLOID PROCESS WITH OSSIFICATION OF THE STYLOHYOID LIGAMENT

The styloid process of the temporal bone is an elongated bony projection presenting a variable length as demonstrated in osteometric and radiological studies conducted with different techniques: three-dimensional computed tomography (3dct) or dental panoramic three-dimensional scanning. An elongated styloid process can cause neck pain , dysphagia, headache, sore throat, ear pain, mandibular dysfunction which characterize Eagle’s syndrome. Here we present a rare image of an abnormally long styloid process with ossification of left stylohyoid ligament belonging to a bone collection of the local anatomical museum , part of our department, and discovered during routine osteology classes .Also if a direct relation between the length of the styloid process and syndrome of Eagle is not always obvious ,radiologists , neurologists,neurosurgeons, dentists, anesthetists and otolaryngologists could be aware of this bone anomaly to diagnose this syndrome

The innervation of human muscularis mucosae: an ultrastructural study

The muscularis mucosae, a thin band of smooth muscle located at the base of the gastrointestinal mucosa, has been the topic of very few studies .The muscularis mucosae might regulate the absorptive and secretory functions of the gut through movements of the mucosal surface (1).The autonomic innervation of this tissue is almost completely unknown.Therefore we have carried out an ultrastructural study on nerve fibers of muscolaris mucosae by using archived mucosal rectal biopsies of children of different age , examined in the past for the diagnosis of neurometabolic disease and resulted negative. Nerve fibers of muscularis mucosae were unmyelinated. They contain several axons with the characteristics of intervaricose tract completely or almost surrounded by Schwann cells . Other axons in the nerve fibers appear as varicosities partly covered with Schwann cell cytoplasm or naked, and filled with vesicles and mitochondria .The vesicles in the same varicosity appear pleomorphic: small clear-core vesicles , dense -core of small diameter or less often dense-core of larger type. The membrane of muscle cells often protruded toward the varicosity . No synaptic specialization was observed.With very low frequency we found varicosities in intimate contact with the plasmalemma . Pleomorphic vesicles inside the same varicosity suggest a complex neurotransmission based on the release of classical transmitter and cotransmitters.The physiological relevance of these nerves remains unclear. Strips of longitudinal muscularis mucosae isolated from the human, guinea pig and rat colon responded with concentration-dependent contractions to the application of several spasmogens (1). In the human muscularis mucosae, neurokinin A was most potent, followed by carbachol, prostaglandin F2 and acetylcholine. These findings suggest the possibility that the muscularis mucosae is innervated by excitatory cholinergic nerves (1).On the other hand in oesophagus exogenously applied adrenaline inhibited spontaneous activities of the muscularis mucosae motor activity. Adrenergic nerves might inhibit spontaneous motility via the inhibition of cholinergic neurotransmission. VIP- , NPY-, CGRP- and galanin-immunoreactive nerve fibers were observed in the human esophageal muscularis mucosae but their function remains unknown (2)

Variations in the length of the styloid process and the possible consequences on muscle ligamentous systems with the mandible and the hyoid bone

The styloid process of the temporal bone has a variable length as demonstrated in studies conducted with different technique: three-dimensional computed tomography or dental panoramic three-dimensional scanning. Data on the osteometric values of the styloid process is scanty with significant length differences existing between the studies attributed to different races or ethnicities.The abnormal length can be in some cases accompanied by a set of symptoms, characterized by neck pain, dysphagia, headache, sore throat, ear pain, mandible dysfunction clinically framed in Eagle’s syndrome. We present an osteometric study on the length of the styloid process of a collection of dried skulls belonging to the museum of Anatomy “Leonetto Comparini “ at the University of Siena. All skulls came from the local psychiatric hospital. For measurement we employed a digital caliper . The data were analyzed through a free statistical software (Salstat 2) . Average and standard deviation (sd), were calculated. Univariate analysis of the length of the styloid process gave the following results: average: 27 mm ; sd : 7 mm ; normal range : average +/- 2 sd : 41-13 mm. The longest styloid process was 52 mm and the shortest had a length of 0.5 mm .In one case we discovered a skull with stylohyoid calcified ligament on one side . The styloid process was long 50 mm on the right and 70 mm on the left where is the tip calcified .An abnormal long styloid process>41 mm is present in 6% of items in our biometric study . The abnormal variations in length are put in relation to the possible anatomical change of the muscular and ligamentous structures of the styloid process by drawings of a case with a marked elongation of the styloid process.The shortening of the stylomandibular ligament that we suppose considering the distance from the angle of mandible of the tip and the possible change in direction could cause difficult in the protrusion of mandible and in mastication. The shortening of stylohyoid ligaments and muscles, could cause difficult in movement of os hyoid and in raising or lowering of larynge during swallowing

Effects of endogenous morphine deprivation on memory retention of passive avoidance learning in mice

Memory and the processes of learning in mammals are well known to be affected by opioid agonists such as morphine, which has been proven to interfere and cause amnesia. The presence of endogenous morphine has been demonstrated in various tissues from mammals to invertebrates. In this study, we have investigated the effects caused by in-vivo immunodepletion of endogenous morphine on working memory under different experimental conditions. When mice were submitted to fasting, a stress condition, acquisition and consolidation of memory were significantly impaired compared to controls. This was demonstrated by a decrease in entry latency into the dark room in the retention session of the passive avoidance test. This effect was significantly reversed to baseline values when endogenous morphine was depleted from the extracellular brain space. These findings support a role for endogenous morphine in weakening memory processes under stress conditions

Sternal foramina : anatomy and clinical significance

Vengono presentati casi di forami sternali multipli e viene discussa l'importanza della conoscenza da parte dei clinici di questa anomalia