The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the ultrastructure of roots of Pisum sativum L. after seven days of Cd treatment (10, 50, 100, and 200 μM CdSO4). Our results showed that phenylalanine ammonia-lyase (PAL) activity and the amount of Cd accumulated in the roots were significantly positively correlated with the Cd concentration used in our experiment. However, Cd caused a decrease of all studied antioxidative enzyme activities (i.e., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX)). The analysis of the ultrastructure (TEM) showed various responses to Cd, depending on Cd concentrations. In general, lower Cd concentrations (50 and 100 μM CdSO4) mostly resulted in increased amounts of oil bodies, plastolysomes and the accumulation of starch granules in plastids. Meanwhile, roots treated with a higher concentration of Cd (200 μM CdSO4) additionally triggered protective responses such as an increased deposition of suberin lamellae in the endodermal cell walls. This indicates that Cd induces a complex defense response in root tissues.

Unbiased stereological methods were used to morphometrically examine and compare the medial geniculate body (MGB) of two species from different mammalian orders. The MGB had a similar nuclear pattern, and it was parcelled into three major cytoarchitectural areas: the dorsal nucleus (MGd), the ventral nucleus (MGv) and the medial nucleus (MGm). The MGd was predominant in the fox, where it contributed nearly 50% to the total MGB volume, while in the rabbit, the MGv was insignificantly larger than the MGd. In both species, the percentage contribution of the MGm was the lowest. The MGd in the fox was also characterized by twice as many neurons per mm(3) as in the rabbit, whereas a reverse proportion was observed in the MGm, although the numerical density in the MGv was very similar in both species. The total number of MGB neurons in the fox was over twice higher than that in the rabbit. The variability in the percentage contribution of the MGd, MGv and MGm cells to the total neuronal population of the MGB was different in both mammals. In the rabbit, there was a larger contribution from the MGv and MGm, while in the fox, the MGd was predominant. These data demonstrate that the main areas of the MGB complex differ in terms of the morphometric characteristics in both species. Our results also show that the negative correlation between the volume and numerical density in the sensory centres of the brain might not be as distinct as in the non-sensory brain structures.

Abstract:This study provides a detailed description of cocaine-and amphetamine-regulated transcript (CART) distribution and the co-localization pattern of CART and gonadotropin releasing hormone (GnRH), somatostatin (SOM), neuropeptide Y (NPY), cholecystokinin (CCK), and substance P (SP) in the preoptic area (POA) of the domestic pig. The POA displays a low density of immunoreactive cells and rich immunoreactivity for CART in fibers. CART-immunoreactive (CART-IR) cell bodies were single and faintly stained, and located in the medial preoptic area (MPA) and the periventricular region of the POA. A high density of immunoreactive fibers was observed in the periventricular preoptic nucleus (PPN); a high to moderate density of fibers was observed in the MPA; but in the dorso-medial region of the MPA the highest density of fibers in the whole POA was observed. The lateral preoptic area (LPA) exhibited a less dense concentration of CART-immunoreactive fibers than the MPA. The median preoptic nucleus (MPN) showed moderate to low expression of staining fibers. In the present study, dual-labeling immunohistochemistry was used to show that CART-IR cell bodies do not contain any GnRH and SP. CART-positive fibers were identified in close apposition with GnRH neurons. This suggests that CART may influence GnRH secretion. Double staining revealed that CART-IR structures do not co-express any of the substances we studied, but a very small population of CART-IR fibers also contain

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The distribution and morphology of neurons containing cocaine- and amphetamine-regulated transcript (CART) was investigated in the pig amygdala. CART- immunoreactive (CART-IR) cell bodies were rarely observed in the pig amygdala and most often they were present in the posterior (small-celled) parts of the basolateral and basomedial nuclei. In all other subdivisions only a small number of randomly scattered pericarya were present. In every region studied the CART-IR neurons formed a heterogeneous population consisting mostly of small, rounded or slightly elongated cell bodies, with a few poorly branched, smooth dendrites. In general, the morphological features of these cells clearly resembled non-pyramidal Golgi type II interneurons. Some randomly scattered CART-IR cell bodies were significantly larger and they demonstrated features of pyramidal-like Golgi type I projecting neurons. The highest densities of CART-IR fibres were evident within the central and medial nuclei. Moderate to high expression was found within the large-celled part of the basolateral nucleus and moderate to low levels in the lateral, basomedial and cortical nuclei. The routine double-labelling studies with antisera directed against CART and somatostatin (SOM), or neuropeptide Y (NPY), or cholecystokinin (CCK), or vasoactive intestinal peptide (VIP), or substance P (SP) demonstrated that, in general, these peptides do not co-exist in the CART-IR neurons. However, small subpopulations of the CART-IR fibres contained SOM, CCK, VIP or SP together.