Distribution, structure and projections of the frog intracardiac neurons.

Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 µm. Average total length of processes from soma and hillock was less, 118 ± 27 µm and 109 ± 24 µm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia.

Growth factors, their receptors, neuropeptide-containing innervation, and matrix metalloproteinases in the proximal and distal ends of the esophagus in children with esophageal atresia.

OBJECTIVE: The pathogenesis of esophageal atresia (EA) remains unknown despite a relatively high incidence of this anomaly in population affecting 1 newborn per 3000 live births. The aim of this study was to examine the relative occurrence of growth factors, their receptors, neuropeptide-containing innervation, and tissue-degradating enzymes--matrix metalloproteinases--in the proximal and distal parts of the esophagus with EA. MATERIALS AND METHODS: A histopathological study was conducted on 15 patients with EA. Tissues were processed for NGFRp75, PGP 9.5, TGF-ß, FGFR, VEGF, EGFR and MMP-2 by means of biotin-streptavidin immunohistochemistry. RESULTS: In the control and EA-affected distal esophageal specimens, numerous and abundant NGFR-containing structures were detected, while in the proximal part of the esophagus, a decrease in their number was observed in patients. PGP 9.5 also marked neuronal structures similarly. TGF-ß was found only in occasional cells in the EA-affected esophageal specimens, while control material demonstrated moderate to numerous TGF-ß-containing structures. Abundance of FGFR and only occasional appearance of VEGF-positive cells were found in both the control and EA-affected material. A moderate number of connective tissue cells in controls contained EGFR. Compared with controls, the number of MMP-2 expressing cells in the EA-affected tissues was decreased in the proximal esophagus. CONCLUSIONS: A decrease in PGP 9.5-containing neuronal structures in the proximal esophagus supports insufficient innervation of this part of the organ in EA. A decrease in MMP-2 positive cells in the esophageal atresia-affected proximal esophagus indicates also a possible decrease of tissue adaptive and regenerative reactions. Low expression of TGF-ß and almost the absence of EGFR in the EA-affected specimens may result in disturbances of cell growth, proliferation, and differentiation, indicating a significant role of these substances in morphopathogenesis of EA. FGFR and VEGF seem not to characterize EA pathogenesis.

Age-related structural and neurochemical changes of the human superior cervical ganglion.

The aim of this study was to investigate age-related morphological and neurochemical changes in the human superior cervical ganglion (SCG). Thirty-seven superior sympathetic human cervical ganglia of young, adult, and aged subjects were examined using morphometric analysis, biotin-streptavidin immunohistochemistry for detecting neurofilament, myelin protein, protein gene product 9.5, nerve growth factor receptor p75 in sympathetic neurons and nerve fibers. Morphometric parameters of neurons (area, long and short axis, shape factor of the neuron body, nucleus, cytoplasm, and lipofuscin) were investigated in every sixth serial section of the ganglion. Seven hundred neurons with clearly visible nuclei were measured in each studied group. The present study showed that human SCG of older subjects had larger areas of neuron body, cytoplasm and nucleus, a lower shape factor, an increased amount of lipofuscin, and a greater number of large-size neurons, as compared to SCG obtained from young subjects. Neuronal cytoskeletal alterations manifested themselves through a decreased number of neurofilament-positive neurons were detected in old human SCG. The amount of myelinated fibers decreased with age, although the amount of myelinated fibers in the young and the adult subjects varied from few to a moderate number. PGP 9.5 immunoreactivity varied in different age groups. A marked reduction of nerve growth factor receptor p75 in old human sympathetic neurons was detected. In conclusion, the findings of this study confirm age-related morphological changes in the human SCG. Structural neuronal changes may influence the deterioration of neuronal functional capacity, neuronal plasticity, and regenerative characteristics.

Structural changes of the human superior cervical ganglion following ischemic stroke.

OBJECTIVE: The sympathetic nervous system participates in the modulation of cerebrovascular autoregulation. The most important source of sympathetic innervation of the cerebral arteries is the superior cervical ganglion. The aim of this study was to investigate signs of the neurodegenerative alteration in the sympathetic ganglia including the evaluation of apoptosis of neuronal and satellite cells in the human superior cervical ganglion after ischemic stroke, because so far alterations in human sympathetic ganglia related to the injury to peripheral tissue have not been enough analyzed. MATERIALS AND METHODS: We investigated human superior cervical ganglia from eight patients who died of ischemic stroke and from seven control subjects. Neurohistological examination of sympathetic ganglia was performed on 5 microm paraffin sections stained with cresyl violet. TUNEL method was applied to assess apoptotic cells of sympathetic ganglia. RESULTS: The present investigation showed that: (1) signs of neurodegenerative alteration (darkly stained and deformed neurons with vacuoles, lymphocytic infiltrates, gliocyte proliferation) were markedly expressed in the ganglia of stroke patients; (2) apoptotic neuronal and glial cell death was observed in the human superior cervical ganglia of the control and stroke groups; (3) heterogenic distribution of apoptotic neurons and glial cells as well as individual variations in both groups were identified; (4) higher apoptotic index of sympathetic neurons (89%) in the stroke group than in the control group was found. CONCLUSIONS: We associated these findings with retrograde reaction of the neuronal cell body to axonal damage, which occurs in the ischemic focus of blood vessels innervated by superior cervical ganglion.

Expression of progesterone receptors in bovine corpus luteum during pregnancy.

The expression of progesterone receptors and matrix ribonucleic acid in 37 corpora lutea in 1-7 month's pregnant cows was investigated. Corpora lutea were obtained from slaughtered animals. Progesterone receptors expression was confirmed using biotin-streptavidin immunohistochemistry. Matrix ribonucleic acid expression was studied using pyronin staining by Unna-Brashe method. The expression of progesterone receptors was the highest in the luteal cells of the one-month pregnancy corpus luteum. It decreased significantly (p<0.05) from the third to the fourth month of pregnancy, but there was no significant difference in the expression of progesterone receptors from the first to the second and from the second to the third month of pregnancy. Also, there was no significant difference in the expression of progesterone receptors from the fourth to the fifth month and from the fifth to the sixth month of pregnancy. The expression of matrix ribonucleic acid also decreased during pregnancy, but gradually, with no significant monthly differences. It decreased significantly (p<0.05) from the sixth to the seventh month of pregnancy only. Our study shows that both indices - progesterone receptors and matrix ribonucleic acid decrease in the steroidogenic luteal cells during pregnancy and that a strong linear correlation (r=0.88) exists between these indices.