Sex differences of parvalbumin-immunoreactive neurons in the rat brain

During the last two decades numerous studies have proven the existence of sexual dimorphism in the brain of lower vertebrates, birds, and mammals. Differences between males and females have been found in various components of central nervous system (CNS), including volumes of certain nuclei, numbers of neurons and synaptic contacts, size of somata and outgrowths, as well as differences in neurotransmitter systems. The mechanisms by which these dimorphic features appear remain an open question for further elucidation. It is not clear yet how the morphological variations observed between sexes during development could be related to functional consequences in the adult organism.Biomedical Reviews 1997; 7: 91-96

Age-related changes in the catecholaminergic neurons of the mesopontine tegmentum in the rat

Immunohistochemistry and computer assisted image analysis were used to examine the age-related changes in tyrosine hydroxylase- (TH-) immunoreactivity in substantia nigra (SN), ventral tegmental area (VTA), locus ceruleus (LC) and dopamine-betahyroxylase- (DBH-) immunoreactivity in LC and subceruleus nuclei of the rat. The findings in 3-month-old rats were compared with 28-month-old rats. In SN TH-positive neurons were concentrated in pars compacta and to a lesser extent - in pars lateralis. In VTA the TH-positive neurons were present over the entire area. In LC the immunoreactive perikarya were densely arranged and superimposed, but in subceruleus nuclei they were less numerous and individual cells were clearly discernible. The DBHimmunoreaction distinctly demonstrated the noradrenergic LC and subceruleus neurons. The results indicate of only subtle signs of cell loss in the dopaminergic neuronal population of SN and VTA, whilst the cell loss of the noradrenergic neurons in LC and subceruleus nuclei is evident. On the other hand, considerable age-related dendritic alterations were observed in all catecholaminergic nuclei. Cross-sectional area and optical density (OD) of the TH-immunoreactive neurons in SN, VTA and LC, and of the DBH-immunoreactive neurons in LC and subceruleus nuclei were investigated. In aging the cross-sectional area decreased statistically and OD of the neurons in SN decreased with 13%. In VTA the cross-sectional area did not change its dimensions, while the OD increased with 19%. In LC and subceruleus nuclei the cross-sectional area decreased with 36% and the OD of the neurons decreased with 16%. In conclusion, the most resistant to age-related changes catecholaminergic region in the rat is the VTA, followed by the pars compacta of SN. Rodent LC is a very vulnerable region.Biomedical Reviews 2007; 18: 45-58

Neuromelanin-containing, catecholaminergic neurons in the human brain: ontogenetic aspects, development and aging

The present review compiles data on the development and aging ofneuromelanin (NM)-containing neurons in the central nervous system. Neuromelanin is brownish-to-black pigment that accumulates in the catecholaminergic (noradrenergic and dopaminergic) neurons and is a reliable natural marker that delineates the A1-A14 catecholaminergic groups of Dahlstrom and Fuxe in the human brain. The pigmentation of noradrenergic locus ceruleus neurons starts earlier than that of dopaminergic substantia nigra, but also a considerable individual variability is present. The pigmentation is well advanced in adolescence. The data at what age the maximal pigmentation is reached are controversial, as are the data on the cell loss in the NM-containing neuronal populations by normal aging. Thus, the participation ofNM in the pathogenesis of Parkinson`s disease remains enigmatic.Biomedical Reviews 2002; 13: 39-47

Tarsal tunnel syndrome caused by anomalous muscle: case report

Accessory muscles within the tarsal tunnel have been reported as a rare cause of tarsal tunnel syndrome. The most common variation provoking this pathologic condition is the flexor digitorum accessorius longus muscle. Herein, we present a rare case of a patient with tarsal tunnel syndrome due to this muscular variation. The discussion of this case report can prompt foot and ankle surgeons to be more aware of this infrequent finding

Comparative electron microscopic and immunohistochemical study of stromal cells in giant cell tumor of bone

Giant cell tumor of bone is an osseous neoplasm that is histologically benign but clinically shows local aggression and high rate of recurrence. The histogenesis of this lesion remains unclear. The histological appearance does not predict the clinical outcome and there are still many unanswered questions with regard to both its treatment and prognosis. In order to further clarify this lesion, we examined ultrastructurally and immunohistochemically the tumor mononuclear cells in ten patients operated on in our hospital for matrix metalloproteinase-9. Positive reaction was detected in the spindle-like stromal cells of giant cell tumor of bone and these cells had the ultrastructural characteristics of fibroblastic cells. The other mononuclear cells did not express matrix metalloproteinase-9 and showed ultrastuctural characteristics of macrophage-like cells. The positive reaction for matrix metalloproteinase-9 in all patients clearly shows that this protease may play a key role in the pathophysiology of giant cell tumor of bone

Light microscopic immunocytochemical identification of leucine enkephalin

Leucine-enkephalin is a potent and naturally-occurring opioid peptide which serves to inhibit other neurotransmitters involved with pain perception, thereby reducing its emotional and physical impact. Nevertheless, there is little data in the literature concerning leucine-enkephalin-immunoreactivity (Leu-enk-ir) in the human claustrum. The objectives of this study were to confirm the existence of leucine-enkephalin immunoreactive neurons and fibers in the human claustrum. Light microscopy was used to describe their morphology and distribution. Samples of claustrum were obtained from the brains of two females (39 and 48 years of age) and two males (27 and 42 years of age). The brains did not show any overt signs of pathology or trauma. Immunoreactivity to Leuenk was assessed via the Avidin-Biotin Complex Method. Light-microscopic analysis confirmed the presence of Leu-enk-ir neurons and fibres in all areas of the human claustrum. The cell bodies varied in shape and size, and were divided into three groups: small, medium and large. The density of immunostaining varied both within and between the cell types, with some neurons, staining more darkly or lightly than others. The large and medium sized cells most likely correspond to claustrocortical projection neurons while the small-sized cells appear to be inhibitory interneurons. It is our hope that these results will be contributed to a better understanding the functions of claustrum, in both health and disease, given its relationship with the development of autism, schizophrenia, Alzheimer disease, Parkinson disease and Huntington disease

Variety of transversus thoracis muscle in relation to the internal thoracic artery: an autopsy study of 120 subjects

<p>Abstract</p> <p>Background</p> <p>The transversus thoracis muscle is a thin muscular layer on the inner surface of the anterior thoracic wall that is always in concern during harvesting of the internal thoracic artery. Because the muscle is poorly described in the surgical literature, the aim of the present study is to examine in details its variations.</p> <p>Methods</p> <p>The data was obtained at standard autopsies of 120 Caucasian subjects (Bulgarians) of both sexes (97 males and 23 females), ranging in age from 18 to 91 years (mean age 52.8 ± 17.8 years). The transversus thoracis morphology was thoroughly examined on the inner surface of the chest plates collected after routine incisions.</p> <p>Results</p> <p>An overall examination revealed that in majority of cases the transversus thoracis slips formed a complete muscular layer (left - 75.8%, right - 83.3%) or some of the slips (left - 22.5%, right - 15%) or all of them (left - 1.7%, right - 1.7%) were quite separated. Rarely (left - 3.3%, right - 5.8%), some fibrous slips of the transversus thoracis were noted. In 55.8% of the cases there was left/right muscle symmetry; 44.2% of the muscles were asymmetrical. Most commonly, the highest muscle attachment was to the second (left - 53.3%, right - 37.5%) or third rib (left - 29.2%, right - 46.7%). The sixth rib was the most common lowest attachment (left - 94.2%, right - 89.2%). Most frequently, the muscle was composed of four (left - 31.7%, right - 44.2%) or fifth slips (left - 53.3%, right - 40.8%).</p> <p>Conclusions</p> <p>This study provides detailed basic information on the variety of the transversus thoracic muscle. It also defines the range of the clearly visible, uncovered by the muscle part of the internal thoracic artery and the completeness of the muscular layer over it. The knowledge of these peculiar muscle-arterial relations would definitely be beneficial to cardiac surgeon in performing fast and safe arterial harvesting.</p

Symptomatic Os Subtibiale Associated with Chronic Pain Around the Medial Malleolus in a Young Athlete

An os subtibiale is a rare accessory bone located below or behind the medial malleolus. Herein we present a rare case of a painful os subtibiale in a young triathlete who presented with pain, redness and swelling below his left medial malleolus. Plain radiographs and three-dimensional computed tomography revealed a well-defined oval bone distal to the left medial malleolus. After conservative treatment failed, the ossicle was excised in an open surgery with complete resolution of symptoms. This case report emphasizes the need for clinical awareness of different anatomical variations of the bones of the foot