Histochemical and morphometric studies of perfneuronal nets in the retrosplenial cortex of albino rat

Reticular or net-like perineuronal coatings, termed perineuronal nets [PNs], enriched with proteoglycans [PGs] and/or glycoproteins [GPs] were demonstrated to ensheath cell surfaces of certain neuronal circuits in the central nervous system of mammals, reptiles and fishes. In this investigation, three types of coated neuronal circuits were histochernically demonstrated in the adult rat retrosplenial cortex [RSC]; PGs-, GPs- and PGs/GPs- coated neuronal types. The PGs coated neurons were histochemically detected with a cationic iron colloid [CIC] staining or CIC/Bodian enhancement procedure. The GPs coated ones were detected with certain plant lectins from Vicia villosa agglutinin VVA Wisteria florihunda agglutinin WFA or Glycine max agglutinin SBA for N-acetylgalactosamine-binding. The netassociated neurons were mostly distributed throughout the cortical layers II-V Their mean number per UA [60.15 micro M[2] was ranged from 9.87 +/- 0.43-10.50+2.61 in 8-month old rat and forming about 24-26% of total neuronal population. Statistical Analysis revealed that the mean numbers of PGs, GPs and PGs/GPs coated cells were 0.84 +/- 0.07, 6.33 +/- 0.34 and 2.70 +/- 0.22, respectively. Their percentages represented about 9%, 64% and 27% of total coated neurons in RSC, respectively. Notably, the labeled retrosplenial neurons underwent a non-significant increase in number with progression of age during the first post natal year; however, they declined thereafter toward senility. This data indicated that the extracellular matrix of net- associated retrosplenial neurons in adult albino rat was enriched with GPs and/or PGs molecules and this neurochemical heterogeneity might have diverse biological and functional properties of the neurons in RSC

Ultrastructural developmental study of bronchial epithelium in one-humped camel

The putative respiratory epithelium lining of the bronchial tree of 20-60 mm crown-rump length [CRL] camel fetuses displayed the staggered nuclear organization characteristic of single cilium on their apical surfaces. The bronchial epithelium revealed a clear evidence of ciliogenesis, which occurred as early as 70 mm CRL, starting in the main bronchi and gradually proceeding distally, along the developing bronchial tree. The ciliogenic cells were gradually increased with gestational age. in fetuses of 70-370 mm CRL, the bronchial epithelium displayed a myriad of disintegrating sloughed apoptotic cells intermingled with ciliated and ciliogenic cells together with few non-ciliated microvillus types. Mitochondrial swelling, dilatation of the rough endoplasmic reticulum, vacuolation of the of the cytoplasm, distortion of the intercellular junctions, together with clumping of the nuclear chromatin were the early signs of cellular apoptosis. With time, the regressing apoptotic cells tended to detach themselves from their neighbors and underlying basement membrane moved upwards and sloughed into the airway lumen. These morphological alterations, concerning the disintegrating sloughed apoptotic cells, were first observed in the main bronchi and gradually proceeded by age towards the bronchiolar branches. In adult camels the bronchial epithelium was formed mainly of ciliated and non-ciliated microvillus cells; however, that at term of gestation was composed of ciliated cells, non-ciliated microvillus cells; however, that at term of gestation was composed of ciliated cells, non-ciliated microvillus types together with some cells possessing surface microplicae