Maria Cristina Faccioni-Heuser

Effect of Treadmill Exercise on Serotonin Immunoreactivity in Medullary Raphe Nuclei and Spinal Cord Following Sciatic Nerve Transection in Rats

The serotoninergic system modulates nociceptive and locomotor spinal cord circuits. Exercise improves motor function and changes dopaminergic, noradrenergic, and serotonergic central systems. However, the direct relationship between serotonin, peripheral nerve lesion and aerobic treadmill exercise has not been studied. Using immunohistochemistry and optic densitometry, this study showed that the sciatic nerve transection increased the serotoninergic immunoreactivity in neuronal cytoplasm of the magnus raphe nuclei of trained and sedentary rats. In the dorsal raphe nucleus the increase only occurred in sedentary-sham-operated rats. In the spinal cord of trained, transected rats, the ventral horn showed significant changes, while the change in dorsal horn was insignificant. Von Frey’s test indicated analgesia in all exercise-trained rats. The sciatic nerve functional index indicated recovery in the trained group. Thus, both the aerobic treadmill exercise training and the nervous lesion appear to contribute to changes in serotonin immunoreactivity.

An ultrastructural study of cell death in the CA1 pyramidal field of the hippocapmus in rats submitted to transient global ischemia followed by reperfusion

In the course of ischemia and reperfusion a disruption of release and uptake of excitatory neurotransmitters occurs. This excitotoxicity triggers delayed cell death, a process closely related to mitochondrial physiology and one that shows both apoptotic and necrotic features. The aim of the present study was to use electron microscopy to characterize the cell death of pyramidal cells from the CA1 field of the hippocampus after 10 min of transient global ischemia followed by short reperfusion periods. For this study 25 adult male Wistar rats were used, divided into six groups: 10 min of ischemia, 3, 6, 12 and 24 h of reperfusion and an untouched group. Transient forebrain ischemia was produced using the 4‐vessel occlusion method. The pyramidal cells of the CA1 field from rat hippocampus submitted to ischemia exhibited intracellular alterations consistent with a process of degeneration, with varied intensities according to the reperfusion period and bearing both apoptotic and necrotic features. Gradual neuronal and glial modifications allowed for the classification of the degenerative process into three stages: initial, intermediate and final were found. With 3 and 6 h of reperfusion, slight and moderate morphological alterations were seen, such as organelle and cytoplasm edema. Within 12 h of reperfusion, there was an apparent recovery and more ‘intact’ cells could be identified, while 24 h after the event neuronal damage was more severe and cells with disrupted membranes and cell debris were identified. Necrotic‐like neurons were found together with some apoptotic bodies with 24 h of reperfusion. Present results support the view that cell death in the CA1 field of rat hippocampus submitted to 10 min of global transient ischemia and early reperfusion times includes both apoptotic and necrotic features, a process referred to as parapoptosis.

Ultrastructural features of neurons and synaptic contacts in the posterodorsal medial amygdala of adult male rats

The aim of the present study was to describe the ultrastructure of neurons (from eight animals) and to analyse the synaptic terminal distribution (from two animals) in the posterodorsal subnucleus of the medial amygdala (MePD) of adult male rats. Using transmission electron microscopy, it was possible to identify many spiny and aspiny dendrites, unmyelinated axonal bundles, single axonal processes, a few myelinated axons, blood vessels and glial processes in the neuropil. Axodendritic synapses were the most frequently observed (67.5%), appearing to be of either the inhibitory or the excitatory types. The presynaptic region contained round or flattened vesicles that occurred either singly or with dense‐cored vesicles (DCVs). The dendrites often received many synapses on a single shaft, and axon terminals displayed synaptic contacts with one or more postsynaptic structures. Dendritic spines showed different morphologies and the synapses on them (23.1%) formed a single and apparently excitatory synaptic contact with round, electron‐lucid vesicles alone or, less frequently, with DCVs. Inhibitory and excitatory axosomatic synapses (8.2%) and excitatory axoaxonic synapses (1.2%) were also identified. The present report provides new findings relevant to the study of the MePD cellular organization and could be combined with other morphological data in order to reveal the functional activity of this area in male rats.

Balance and coordination training after sciatic nerve injury.

Introduction: Numerous therapeutic interventions have been tested to enhance functional recovery after peripheral nerve injuries. Methods: After sciatic nerve crush in rats we tested balance and coordination and motor control training in sensorimotor tests and analyzed nerve and muscle histology. Results: The balance and coordination training group and the sham group had better results than the sedentary and motor control groups in sensorimotor tests. The sham and balance and coordination groups had a significantly larger muscle area than the other groups, and the balance and coordination group showed significantly better values than the sedentary and motor control groups for average myelin sheath thickness and g‐ratio of the distal portion of the nerve. Conclusions: The findings indicate that balance and coordination training improves sciatic nerve regeneration, suggesting that it is possible to revert and/or prevent soleus muscle atrophy and improve performance on sensorimotor tests. Muscle Nerve 44: 55–62, 2011.

Aspectos morfológicos e de incubação em três espécies de Corbicula Mühlfeld, no lago Guaíba, Rio Grande do Sul, Brasil (Bivalvia, Corbiculidae)

Three species of Corbicula identified in Guaiba Lake are compared in respect to the external morphology of their soft parts and aspects of branchial incubation. Morphological differences are most obvious in the siphons. For the first time, individuals of C. fluminea have been found with incubation occurring in the outer as well as the inner demibranchs. Individuals of C. largillierti showed incubation only in the inner demibranchs. In specimens identified as C. aff. fluminalis, tetrabranchial incubation predominated.

Balance and coordination training and endurance training after nerve injury

Introduction: Different rehabilitation treatments have proven useful in accelerating regeneration. Methods: After sciatic nerve crush in rats, we tested balance and coordination training (BCT) and endurance training (ET) through sensorimotor tests and analyzed nerve and muscle morphology. Results: After BCT and ET, rats performed better in sensorimotor tests than did non‐trained animals. However, only BCT maintained sensorimotor function during training. Furthermore, BCT and ET produced significantly larger muscle area than in non‐trained animals. Conclusions: These findings indicate that BCT and ET, when initiated in the early phase after sciatic nerve injury, improve morphological properties of the soleus muscle and sciatic nerve, but only the task‐oriented BCT maintained sensorimotor function. The success of rehabilitative strategies appears to be highly task‐specific, and strategies that stimulate sensory pathways are the most effective in improving balance and/or coordination parameters. Muscle Nerve 51: 83–91, 2015

Exercise training improves the soleus muscle morphology in experimental diabetic nerve regeneration

In this study we evaluate the effects of exercise training (10 weeks) on soleus muscle morphology in diabetic nerve regeneration after injury by sciatic nerve crush.

Chronic exposure to ethanol causes steatosis and inflammation in zebrafish liver

AIM To evaluate the effects of chronic exposure to ethanol in the liver and the expression of inflammatory genes in zebrafish. METHODS Zebrafish (n = 104), wild type, adult, male and female, were divided into two groups: Control and ethanol (0.05 v/v). The ethanol was directly added into water; tanks water were changed every two days and the ethanol replaced. The animals were fed twice a day with fish food until satiety. After two and four weeks of trial, livers were dissected, histological analysis (hematoxilin-eosin and Oil Red staining) and gene expression assessment of adiponectin, adiponectin receptor 2 (adipor2), sirtuin-1 (sirt-1), tumor necrosis factor-alpha (tnf-a), interleukin-1b (il-1b) and interleukin-10 (il-10) were performed. Ultrastructural evaluations were conducted at fourth week. RESULTS Exposing zebrafish to 0.5% ethanol developed intense liver steatosis after four weeks, as demonstrated by oil red staining. In ethanol-treated animals, the main ultrastructural changes were related to cytoplasmic lipid particles and droplets, increased number of rough endoplasmic reticulum cisterns and glycogen particles. Between two and four weeks, hepatic mRNA expression of il-1b, sirt-1 and adipor2 were upregulated, indicating that ethanol triggered signaling molecules which are key elements in both hepatic inflammatory and protective responses. Adiponectin was not detected in the liver of animals exposed and not exposed to ethanol, and il-10 did not show significant difference. CONCLUSION Data suggest that inflammatory signaling and ultrastructural alterations play a significant role during hepatic steatosis in zebrafish chronically exposed to ethanol.

AN ULTRASTRUCTURAL STUDY OF TEGUMENTAL GLANDS OF THE FIFTH PEREIOPODS OF AEGLA PLATENSIS (ANOMURA: AEGLIDAE)

Abstract Tegumental glands are a ubiquitous feature of the decapod cuticle. In the fifth pair of pereiopods (P5) of Aegla platensis Schmitt, 1942, these tegumental glands (PeTGs) are similar to those described in other decapod crustaceans. Type 1 PeTGs, with mucous and serous cells and type 2 PeTGs, with serous cells only are organized into proximal, medial and distal clusters along the appendage. Both types of PeTGs possess secretory cells arranged concentrically around a central duct. These secretory cells have well developed Rough endoplasmic reticulum (RER) and numerous Golgi Complexes, and possess electron-lucid and electron dense vesicles. The finely granular aspect of the electron-lucid vesicles suggest they contain a mucous-like substance, while electron-dense vesicles probably contain a substance of a proteinaceous nature. Despite various hypotheses, there are few indications that these substances act as cleaning agents. However, the cytoplasm of the secretory cells appear to be composed of concentric lamellas that could be responsible for the production of surfactants (cleaning substances). In the Anomura, P5 is involved in grooming but there presently is insufficient evidence to show that the glands play a role in this process.

Ultrastructural features of the columellar muscle and contractile protein analyses in different muscle groups of Megalobulimus abbreviatus (Gastropoda, Pulmonata)

In Megalobulimus abbreviatus, the ultrastructural features and the contractile proteins of columellar, pharyngeal and foot retractor muscles were studied. These muscles are formed from muscular fascicles distributed in different planes that are separated by connective tissue rich in collagen fibrils. These cells contain thick and thin filaments, the latter being attached to dense bodies, lysosomes, sarcoplasmic reticulum, caveolae, mitochondria and glycogen granules. Three types of muscle cells were distinguished: T1 cells displayed the largest amount of glycogen and an intermediate number of mitochondria, suggesting the highest anaerobic metabolism; T2 cells had the largest number of mitochondria and less glycogen, which suggests an aerobic metabolism; T3 cells showed intermediate glycogen volumes, suggesting an intermediate anaerobic metabolism. The myofilaments in the pedal muscle contained paramyosin measuring between 40 and 80nm in diameter. Western Blot muscle analysis showed a 46-kDa band that corresponds to actin and a 220-kDa band that corresponds to myosin filaments. The thick filament used in the electrophoresis showed a protein band of 100kDa in the muscles, which may correspond to paramyosin.