Age-related changes in the synapses of the rat's neostriatum.

By means of transmission electron microscopy, the age-related changes in axospinous (ASS) and axodendritic (ADS) synapses in the dorsal part of the rostral neostriatum in two groups of Wistar rats: young (3-month-old), and senescent (25-month-old) were examined. The changes in different parameters, characterizing the ASS and ADS: synaptic density (SD), number of synaptic vesicles (SV), number of synaptic contact zone (SCZ), and number of dendritic spines, bearing synapses (DS) were investigated morphometrically. The SD of the ASS decreased significantly during aging, but the SD of the ADS did not changed significantly.

Age-related changes in the NADPH-diaphorase-positive dendrites in the dorsolateral neuronal column of the periaqueductal gray in rat.

The effects of age on the dendritic tree of reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the dorsolateral neuronal column of the periaqueductal gray (DLPAG) in the rat were examined, using NADPH-d histochemistry and computer-assisted analysis. In 26-month-old rats some of the neurons exhibited considerably branched dendrites, while others show amputation stumps, or local swellings in the initial dendritic portion. Quantitative analysis demonstrated that the number of dendritic segments in DLPAG increased with advancing age.

Histological and immunocytochemical data on the differentiation of intestinal endocrine cells in human fetus.

The differentiation of the argyrophil, argentaffin, 5-hydroxytryptamine (5-HT)-, somatostatin (SOM)-, cholecystokinin (CCK)-, substance P (SP)-, methionine-enkephalin (Met-Enk)- and vasoactive intestinal polypeptide (VIP)-immunoreactive entero-endocrine cells (EECs) was examined in human fetuses. A great increase in the frequency of EECs in the duodenum and the rectum was observed between the 7th and 12th gestation week. The differentiation of the EECs advanced distally in the small intestine and proximally in the large intestine.

Age-related changes in the NADPH-diaphorase-positive neuronal perikarya of the dorsolateral column of the periaqueductal gray in the rat.

The distribution of reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) positive neuronal perikarya in the rostral, middle and caudal parts of the dorsolateral periaqueductal gray (DLPAG) in 3-, 12- and 26-month-old rats was compared by means of histochemistry and computer assisted image analysis. The total number, the maximum diameter, the cross-sectional area and the optical density (OD) of the NADPH-d positive neurons were analyzed. The results demonstrate that there are no significant differences in any of the investigated parameters between the left and the right parts of the same age and of the same level.

Contribution of nitric oxide and substance P to nonadrenergic, noncholinergic transmission in the guinea pig ileum.

1. The possible contribution of the nonadrenergic noncholinergic (NANC) transmitters nitric oxide (NO) and substance P (SP) to the contractility of guinea pig isolated ileum was studied by the responses of the longitudinal muscle to electrical field stimulation (0.8 msec, 40 V, 1-20 Hz, 20 sec) of the intrinsic nerves and by the presence and distribution of NADPH-diaphorase- and SP-positive nerve structures in the myenteric plexus.