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.

Aging and the dendritic morphology of the rat laterodorsal and pedunculopontine tegmental nuclei.

The morphological appearance and quantitative parameters characterizing the dendrites of NADPH-diaphorase-stained neurons in the laterodorsal (LDT) and pedunculopontine (PPN) tegmental nuclei of 3-, 12- and 26-month-old rats were studied. All dendritic segments were classified according to the number of terminal and link segments they drain and the vertex analysis was used to quantify the dendritic tree and to determine its configuration. Morphological aberrations of the dendrites as local swelling, nodulation, thinning, shrinkage, folding and even the appearance of stumps were observed with advancing age.

Changes in NADPH-diaphorase neurons of the rat laterodorsal and pedunculopontine tegmental nuclei in aging.

The aim of the present study was to compare the morphological pattern and the quantitative parameters of nitric oxide (NO)-containing neurons in the laterodorsal (LTD) and pedunculopontine (PPN) tegmental nuclei of 3-, 12- and 26-month-old rats. NADPH-diaphorase (NADPH-d) histochemical reaction, as a marker of the cholinergic neurons in the two mesopontine nuclei, and computer-assisted image analysis were used. The relationships between the neurons stained for NADPH-d and choline acetyltransferase (ChAT) were examined using a double-labelling procedure.

Morphological evidence for effects of the aging on the serotoninergic neurons in the rat brainstem nuclei.

The effects of age on the 5-hydroxytryptamine-immunoreactive (5-HT-IR) neurons in raphe and extrarapheal nuclei of rats were examined using morphometry. Quantitative parameters of the neuronal density and cross-sectional areas of the cell bodies as well as of the length and numbers of the processes of the 5-HT-IR neurons were analyzed in 3-, 12- and 26-month-old-rats. The results showed that aging affected the 5-HT-IR neurons in the rat brainstem nuclei.

Vasopressin- and oxytocin-immunoreactive nerve cells in the aging rat hypothalamus.

Immunohistochemistry and morphometry were used to study the age-related changes in the vasopressin (AVP) and oxytocin (OXT) nerve cells in the paraventricular (PVN), supraoptic (SON) and suprachiasmatic (SCN) nuclei of 3-, 11- and 28-month-old rats. The results showed a statistically significant reduction in the mean number of AVP cells in the PVN, SON and SCN, and of OXT cells in the PVN with advancing age. Different age-related changes in the mean size of the immunoreactive cells were found in the three nuclei: a significant and transitory increase in the AVP and OXT cell sizes in the PVN, a tendency towards increasing the AVP and OXT cell sizes in the SON, and a significant and gradual decrease in the AVP cell size in the SCN.

Age-related changes in basic fibroblast growth factor-immunoreactive cells of rat substantia nigra.

Immunohistochemistry and computer-assisted image analysis were used to examine the age-related changes in bFGF-immunoreactivity in rat substantia nigra (SN). Distribution pattern, number, size and staining intensity of bFGF-immunoreactive (bFGF-ir) cells in pars compacta and pars reticulata of 3-, 12- and 26-month-old rats were compared. The overall distribution of bFGF-immunoreactivity was similar in the three age groups, but changes in the morphological appearance of bFGF-ir somata and processes occurred in aging.

Age-related morphological and morphometrical changes in parvalbumin- and calbindin-immunoreactive neurons in the rat hippocampal formation.

Parvalbumin (PV)- and calbindin (CaBP)-immunostaining in the hippocampal formation of 3-, 11- and 28-month-old Wistar rats was studied using monoclonal antibodies. A quantitative analysis of the densities, cross-sectional areas, length and number of processes of PV-immunoreactive neurons in the hippocampal dentata and CA1 areas of the three age groups was employed. Marked age-related changes in the morphological appearance and in the quantitative parameters characterizing the PV-immunoreactive neurons in both hippocampal regions were observed.

Age-related changes in cholinergic and noradrenergic transmission in the rat cerebellum. A histochemical and immunocytochemical study.

The histochemical and immunocytochemical distribution of some cholinergic and noradrenergic markers was compared in the cerebellum of young adult (3-month old) and aged (24-month old) Wistar rats. A decrease in the density and staining of acetyl cholinesterase (AChE) positive fibers, puncta and Golgi cells was found in both the cerebellar cortex and nuclei of aged rats. The age-related changes in choline acetyltransferase immunoreactivity were less pronounced than the changes in AChE activity.

Age-related changes in serotonin-immunoreactive neurons in the rat nucleus raphe dorsalis and nucleus centralis superior: a light microscope study.

Comparison of serotonin-immunoreactive (SER-IR) neurons in the nucleus raphe dorsalis (NRD) and the nucleus centralis superior (NCS) of 3-month-old and 28-month-old rats was made using qualitative and quantitative immunohistochemical analysis. Significant age-related changes in size and density of the SER-IR somata as well as in the length and number of their processes were demonstrated. A different vulnerability of the SER-IR neurons in both raphe nuclei to aging was observed that may be related to their different structural and functional features.

Qualitative and quantitative glial changes in the hippocampus of aged rats.

Ultrastructure of the glial cells in the CA 1 hippocampal field and some quantitative parameters characterizing the astrocytes in stratum lacunosum-moleculare (str. L-M) of the CA 1 hippocampal field of young-mature (3-month old) and aged (24-month old) rats were examined. The qualitative observations showed structural changes in astrocytes, oligodendrocytes and microglial cells in all layers of the CA1 hippocampal field in aged rats.

Changes in GABA-immunoreactivity and GABA-transaminase activity in rat amygdaloid complex in aging.

The distribution of gamma-aminobutyric acid (GABA), gamma-aminobutyric acid-transaminase (GABA-T) and glial fibrillary acid protein (GFAP) in the amygdaloid complex of young adult (3-month old) and aged (26-month old) Wistar rats was compared by using histo- and immunohistochemical techniques. The study revealed a heterogeneous distribution of GABA-immunoreactive and GABA-T positive nerve cells, fibers and terminals in various amygdaloid nuclei of young adult rats. A significant reduction in the density of GABA-immunoreactive neurons was demonstrated in the amygdala of aged rats.

Age-related changes in serotonin-immunoreactivity in the telencephalon and diencephalon of rats.

Comparison of the appearance and density of the serotoninergic fibers and terminals in some tel- and diencephalon areas of young adult (3 months) and aged (28 months) rats was made immunohistochemically using an antibody to serotonin. In young adult rats a characteristic arrangement of the serotonin-immunoreactive (SER-IR) fibers and terminals in the tel- and diencephalon was observed. In aged rats the distribution pattern was the same but changes in the appearance and density of the SER-IR fibers were demonstrated.

Immuno- and histochemical data on changed GABA transmission in aged rat cerebellum.

The distribution of gamma-aminobutyric acid-immunoreactivity (GABA-I) and activity of GABA-transaminase (GABA-T) was compared in the cerebellum of young adult (3-month old) and aged (24-month old) Wistar rats. A decrease in the density and staining of GABA-immunoreactive and GABA-T positive nerve cells, fibers and puncta were observed in both cerebellar cortex and nuclei of aged rats as compared to those in young adult rats. In contrast, an increased number of Bergmann glia cell and astrocyte processes and bodies in aged rats were demonstrated in GABA immunostaining and histochemical GABA-T reaction.

Changes in the synapses in the parietal cortex of senescent rats.

Quantitative parameters characterizing the density of the synapses, the pre- and postsynaptic elements, and the synaptic contact zones (SCZ) in the parietal cortex of young adult (3-month-old) and aged rats (24 months) were investigated using an automated computer system. A big loss of axospinous, but not of axodendritic synapses, was observed in the aged rats. The parameters for the synaptic vesicles and SCZ were changed also only in the axospinous synapses.

Histo- and immunohistochemical changes in acetylcholinesterase and choline acetyltransferase activities in the amygdaloid complex in aged rats.

Histo- and immunohistochemical distribution of acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) in the amygdaloid nuclei of young adult (3 month old) and aged (26 month old) Wistar rats was compared. AChE staining and ChAT immunoreactivity showed the same regional variations in the amygdaloid nuclei of young adult rats. The density and staining of AChE- and ChAT-positive fibres, terminals, and nerve cells were reduced in aged rat amygdala.

Age-related abnormalities of oxidoreductase activity and mitochondria in rat hippocampal formation.

The activity of oxidoreductases in the hippocampal formation of young adult (3-month old) and aged (24-month old) Wistar rats was compared by histochemical methods. A decreased activity of NADH-diaphorase and dehydrogenases involved in the Krebs cycle and glycolysis as well as an increased activity of glucose-6-phosphate dehydrogenase were demonstrated in the hippocampal nerve cells of aged rats. The activity of oxidoreductases in the glial cells of aged rats was increased.

Quantification of the synapses in the hippocampus of aged rats.

The synapses in the stratum lacunosum-molecular (str. L-M) of CA1 hippocampal field in 3-month old and 24-month old rats were examined using quantitative ultrastructural methods. No significant difference in the density of synapses and postsynaptic dendritic spines was found between the two age groups.

Changes in the synapses of rat hippocampus following pre- and postnatal alcohol exposure.

Quantitative and qualitative changes in the synapses in stratum lacunosum-moleculare of rat hippocampus following pre- and postnatal alcohol exposure were studied. Dense and lamellar bodies, damaged mitochondria, autophagic vacuoles and dilatated cisterns of the smooth endoplasmic reticulum were seen in axons and dendrites. The enlarged glial processes were also found.

Immuno- and histochemical evidence for changed neurotransmission in basal forebrain, hippocampal formation and neocortex of aged rats.

The distribution of choline acetyltransferase- and gamma-aminobutyric acid-immunoreactivity as well as acetylcholinesterase-, gamma-aminobutyrci acid-transaminase- and monoaminooxidase-positive structures in the basal forebrain, hippocampal formation and neocortex of young adult and aged rats was compared. The changes in the staining and density of the immuno- and histochemical positive nerve cells and fibers observed provide evidence for the involvement of different transmitters in normal ageing.

Dendritic changes in the hippocampus of aged rats.

Age-related changes in dendritic branches in stratum lacunosum-moleculare of the CA1 hippocampal field were examined using quantitative ultrastructural methods. A decrease by 38% was demonstrated in the number of dendritic branch profiles per tissue square area in the group of aged (24-month-old) rats as compared to that in the group of young adult (3-month-old) rats. The total volume fraction and total surface of dendrites per volume neuropil were decreased by 23% and 35%, respectively in aged rats.

Synaptic changes in the rat cerebellum following pre- and postnatal alcohol exposure.

The synapses in the cerebellar vermis molecular layer of 6 week old rats treated with small amounts of ethanol (9 g/kg daily) during pre- and postnatal development were examined. Quantitative analysis was made using a digitizer interfaced to a computer. Some relative and absolute (volume) parameters for synapses were calculated using respective computer programs.