[Thickness of cerebral cortex measured using anatomical mesoscopic imaging and magnetic resonance imaging]. / Zmogaus galvos smegenu apsiausto zieves storis, ismatuotas anatominiu mezoskopiniu ir magnetinio rezonanso tomografijos tyrimo metodais.

OBJECTIVE: Magnetic resonance imaging method opened up the possibility for in vivo examination of the anatomy of human brain. For this reason it is interesting and relevant to compare the knowledge accumulated over a number of years during the examination of the composition of dead brain to that obtained from magnetic resonance images. The aim of this study was to determine and compare the thickness of cerebral cortex in human of different age and sex, measured in different sites of the hemispheres when applying anatomical mesoscopic imaging and magnetic resonance imaging. MATERIAL AND METHODS: The thickness of cerebral cortex was measured in symmetrical Brodmann's areas of both hemispheres. The anatomical mesoscopic imaging technique was used for the examination of 2x2-cm cortex samples obtained during autopsy and fixed for 4 weeks in 10% paraformaldehyde. In these samples, cortex thickness was measured in sections perpendicular to the convolution, using an operative microscope, in a mesoscopic image at x16 magnification and with an accuracy of 0.01 mm. Using cerebral magnetic resonance imaging, the thickness of cerebral cortex in live subjects was measured on T1-weighted images of patients examined at the Clinic of Radiology, Kaunas University of Medicine Hospital. The measured cortical field image was magnified to the smallest element of digital image - the pixel - and measured with an accuracy of 0.01 mm. Each of the two techniques was applied for the examination of 20 men and women who were divided into age groups of 20-60 years (n=10) and older than 60 years (n=10). RESULTS AND CONCLUSIONS: Both examination methods yielded a statistically significant difference in the thickness of cerebral cortex between Brodmann's areas 1, 4, and 19. No significant difference in cortex thickness was found between different age and sex groups; however, the findings showed that the difference in cortex thickness between the different age male groups was 4.6% and female - 1.6%. No significant difference using different techniques was found, but the cortex thickness in the fixed samples was reduced by 0.5 cm on average.

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.

Comparative quantitative study of the intrinsic cardiac ganglia and neurons in the rat, guinea pig, dog and human as revealed by histochemical staining for acetylcholinesterase.

This study was conducted to determine the overall number of intrinsic neurons distributed through-out the entire heart, in which most neurons are located inside of intramural ganglia and are hidden to observers. For this reason, we attempted to ascertain: (1) how the number of neurons located inside of intrinsic cardiac ganglion is related to its area, and (2) whether this relationship is dependent on age and species of animals. Hearts of rats, guinea pigs, dogs and humans were used to examine intramural ganglia stained histochemically for acetylcholinesterase (AChE). The number and parameters of neurons located inside of 104 ganglia were estimated in serial sections. Although the revealed intrinsic cardiac ganglia varied extremely in shape and size, two different types were identified: the globular and plain ones. In the plain ganglia, perikarya of side by side situated neurons were always intensely stained for AChE and, being clearly discernible, they could be reliably counted in any plain ganglia on total heart preparations using a contact microscope. Contrarily, neuron somata in the globular ganglia were densely packed above one another and their perikarya were almost indiscernible for the observer. Counting of neurons located inside of globular ganglia was possible in serial sections only. The largest cardiac ganglia were revealed in dogs, in which some globular ganglia containing up to 2000 neurons occupied more than 1 mm2. In spite of evident species-dependent differences with respect to frequency of large ganglia, the majority of intrinsic cardiac ganglia both in humans and animals were comparatively small, involved approximately 100-200 nerve cells and occupied an area ranging from 0.01 to 0.17 mm2. Overall, the number of neurons located inside of globular ganglion was related to its area (correlation coefficient = 0.82). However, the correlation coefficients between the globular ganglion area and its neuron number were unequal in different species (0.92 in guinea pig; 0.80 in dog; 0.72 in human; and 0.44 in rat) as well as dependent on (1) ganglion size (0.8 for ganglia equal to or larger than 0.17 mm2 and 0.6 for ganglia smaller than 0.17 mm2) and (2) age of specimens (respectively, 0.98 for juvenile and 0.87 for adult dogs; 0.71 for infants and 0.54 for aged human). In all examined animals and humans, the mean measurements of neuron perikarya were similar (on average, 23 microm in width, 32 microm in length, and 615 microm2 in area) and differences between them were statistically insignificant. However, neuron perikarya of adult dogs and aged humans were significantly larger than those revealed in the juvenile dogs and infants, respectively. Based on the data of this study, we concluded that the number of intrinsic cardiac neurons may be approximated in the total heart preparation via counting and measuring of intramural ganglia, contours of which are well-discernible following a histochemical reaction for AChE.