Tyrosine hydroxylase protein expression in ventral nerve cord of Neotropical freshwater crab.

Given the importance of catecholamines in coordinating physiological and behavioral responses in brachyurans, the present study was designed to investigate the distribution of tyrosine hydroxylase (TH)-positive cells and fibers in the ventral nerve cord of Dilocarcinus pagei the Neotropical freshwater crab. TH immunoreactivity was visualized in adult crabs of both sexes, during the intermolt period. We found TH-positive cells that have not been previously described in brachyurans. Specifically, we found a pair of TH-positive cells in the ventral region of the thoracic ganglion, and in ventral and dorsal regions of the abdominal (pleonic) ganglion, suggesting catecholaminergic modulation of claws' function and abdominal structures. In addition, great population of TH-positive cells was observed in the subesophageal ganglion, indicating conservation during evolution of catecholamines in this ganglion of decapods. Dopamine is present in cells and fiber tracts of brachyuran ventral nerve cord, projecting to endocrine, cardiac and digestive structures, suggesting widespread modulation and control of physiological functions and behavior. Dopamine plays a central role in movement and psychiatric disorders in humans. Information on dopaminergic function in the nervous system of invertebrates should improve the understanding of its function in more complex systems, such as human beings.

The study of volume density of tracheal ganglions in vitro in new born babies with respiratory distress syndrome.

Volume density of respiratory organs was studied in vitro in newborn babies at different age of gestation (abort, immature, premature and mature) using stereometric method. The total of 23 cases was subject to this study. The respiratory organs (trachea, lungs) were taken from autopsies of newborn babies exited from different causes. For this purpose the tissues were fixed in formalin (10%) solution, cut serially in 7micro and 10micro slabs. Volume density of the respiratory system was assessed stereometricaly using Universal testing system Weibel M 42. We observed that volume density of epithelia, musculature and glands were proportionally present in the tracheal tissue. Cellular interstitial tissue is consistently increasing and corresponds to the developmental stages of the newborn babies. The density of tracheal ganglions is greater in premature ages of immature and premature newborns (p<0,05). Decreased number of ganglion cells is observed in mature ages (p<0,05). This is caused by intensive ramification of ganglions from serosa to deeper layers of trachea right to epithelium. Medium diameter of tracheal ganglions is greater in mature newborn babies and corresponds to developmental ages of babies.