Morphological changes induced by neuropeptide in vitro stimulation of the rat parotid gland

The effect of in vitro stimulation of rat parotid gland with the neuropeptides substance P, calcitonin gene-related peptide and galanin has been studied by microfilament fluorescence staining and in semithin sections, and compared to control incubations and in vitro stimulation with b­adrenergic and muscarinic agonists. Clear-cut aspects of massive granule exocytosis and cytoplasm vacuolation, indicative of protein and fluid secretion respectively, were obvious only after substance P stimulation, whereas treatment with galanin and calcitonin gene-related peptide produced little to no morphological changes. The results being in agreement with the outcome of other methodological approaches, these procedures appear reliable, may be effectively applied to the study of the functional regulation of secretory mechanisms, and may be particularly useful in human tissue analyses

Brain-derived neurotrophic factor (BDNF) and polysialylated-neural cell adhesion molecule (PSA-NCAM) in the human brainstem precerebellar nuclei from prenatal to adult age.

Occurrence and distribution of the neurotrophin brain-derived neurotrophic factor (BDNF) and polysialylated-neural cell adhesion molecule (PSA-NCAM), a neuroplasticity marker known to modulate BDNF signalling, were examined by immunohistochemistry in the human brainstem precerebellar nuclei at prenatal, perinatal and adult age. Western blot analysis performed in human brainstem showed for both molecules a single protein band compatible with the molecular weight of the dimeric form of mature BDNF and with that of PSA-NCAM. Detectability of both molecules up to 72 h post-mortem was also assessed in rat brain. In neuronal perikarya, BDNF-like immunoreactivity (LI) appeared as intracytoplasmic granules, whereas PSA-NCAM-LI appeared mostly as peripheral staining, indicative of membrane labelling; immunoreactivity to both substances also labelled nerve fibres and terminals. BDNF- and PSA-NCAM-LI occurred in the external cuneate nucleus, perihypoglossal nuclei, inferior olive complex, arcuate nucleus, lateral reticular formation, vestibular nuclei, pontine reticulotegmental and paramedian reticular nuclei, and pontine basilar nuclei. With few exceptions, for both substances the distribution pattern detected at prenatal age persisted later on, though the immunoreactivity appeared often higher in preand full-term newborns than in adult specimens. The results obtained suggest that BDNF operates in the development, maturation, maintenance and plasticity of human brainstem precerebellar neuronal systems. They also imply a multiple origin for the BDNF-LI of the human cerebellum. The codistribution of BDNF- and PSA-NCAM-LI in analyzed regions suggests that PSA-NCAM may modulate the functional interaction between BDNF and its high and low affinity receptors, an issue worth further analysis, particularly in view of the possible clinical significance of neuronal trophism in cerebellar neurodegenerative disorders.

The human nucleus cuneatus contains discrete territories that share neurochemical features with the relay nuclei for nociceptive information

Traditionally, the spinal dorsal column and the gracile (GN) and cuneate (CN) nuclei are believed to be involved in somatic tactile and proprioceptive perceptions. However, more recent clinical and experimental studies show that this system is also involved in the neurotransmission of visceral nociceptive stimuli (Willis et al., Proc. Natl. Acad. Sci. USA 96, 7675, 1999; Pale?ek J., Physiol. Res. 53, S125, 2004). Early studies in our laboratory (Del Fiacco et al., Brain Res. 264, 142, 1983; Neuroscience, 12, 591, 1984) showed that, at variance with that of laboratory animals, the human CN contains discrete subregions that are strongly immunoreactive to substance P, a neuropeptide classically involved in pain transmission. Here we provide further information on the chemical neuroanatomy of the human dorsal column nuclei and show that the substance P-immunoreactive subregions of the CN retain the neurochemical features of the protopathic relay nuclei. Tissue distribution of a number of neuropeptides, trophic factors and neuroplasticity-associated proteins was analyzed by immunohistochemistry in postmortem specimens of medulla oblongata from subjects aged 21 gestation weeks to 78 years, with no signs of neuropathology. Immunoreactivity to neuropeptides calcitonin gene-related peptide, leucine- and methionine-enkephalin, somatostatin, galanin, and peptide histidine-isoleucine, to trophins of the Neurotrophin and glial-derived neurotrophic factor families and related receptors, and to the neuroplasticity-associated proteins growth-associated protein-43 and polysialylated-neural cell adhesion molecule labels neuronal elements in restricted areas of the cuneate nucleus, located along its dorsal edge or embedded in the white matter of the cuneate fasciculus. Multiple immunolabelling shows that, with respect to one another, the examined substances are distributed in these regions as in the superficial layers of the spinal dorsal horn and trigeminal subnucleus caudalis. By contrast, the immunoreactivity in the GN is usually sparse and not gathered in definite subregions. The results show that, at variance with that of laboratory mammals, including primates, the human CN contains clear-cut subregions with neurochemical features reminiscent of those present in the relay nuclei for protopathic and pain perception. Moreover, the peculiar localization of the examined substances suggests that the superficial layers of those regions may constitute a “gelatinous subnucleus”. The origin as well as the functional involvement of such innervation remains to be elucidated

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

<p>Abstract</p> <p>Background</p> <p>Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of <it>Pistacia lentiscus </it>L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma.</p> <p>Methods</p> <p>Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone.</p> <p>Results</p> <p>BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA).</p> <p>Conclusions</p> <p>Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.</p

Polysialylated-neural cell adhesion molecule (PSA-NCAM) in the human trigeminal ganglion and brainstem at prenatal and adult ages

<p>Abstract</p> <p>Background</p> <p>The polysialylated neuronal cell adhesion molecule (PSA-NCAM) is considered a marker of developing and migrating neurons and of synaptogenesis in the immature vertebrate nervous system. However, it persists in the mature normal brain in some regions which retain a capability for morphofunctional reorganization throughout life. With the aim of providing information relevant to the potential for dynamic changes of specific neuronal populations in man, this study analyses the immunohistochemical occurrence of PSA-NCAM in the human trigeminal ganglion (TG) and brainstem neuronal populations at prenatal and adult age.</p> <p>Results</p> <p>Western blot analysis in human and rat hippocampus supports the specificity of the anti-PSA-NCAM antibody and the immunodetectability of the molecule in postmortem tissue. Immunohistochemical staining for PSA-NCAM occurs in TG and several brainstem regions during prenatal life and in adulthood. As a general rule, it appears as a surface staining suggestive of membrane labelling on neuronal perikarya and proximal processes, and as filamentous and dot-like elements in the neuropil. In the TG, PSA-NCAM is localized to neuronal perikarya, nerve fibres, pericellular networks, and satellite and Schwann cells; further, cytoplasmic perikaryal staining and positive pericellular fibre networks are detectable with higher frequency in adult than in newborn tissue. In the adult tissue, positive neurons are mostly small- and medium-sized, and amount to about 6% of the total ganglionic population. In the brainstem, PSA-NCAM is mainly distributed at the level of the medulla oblongata and pons and appears scarce in the mesencephalon. Immunoreactivity also occurs in discretely localized glial structures. At all ages examined, PSA-NCAM occurs in the spinal trigeminal nucleus, solitary nuclear complex, vestibular and cochlear nuclei, reticular formation nuclei, and most of the precerebellar nuclei. In specimens of different age, the distribution pattern remains fairly steady, whereas the density of immunoreactive structures and the staining intensity may change and are usually higher in newborn than in adult specimens.</p> <p>Conclusion</p> <p>The results obtained show that, in man, the expression of PSA-NCAM in selective populations of central and peripheral neurons occurs not only during prenatal life, but also in adulthood. They support the concept of an involvement of this molecule in the structural and functional neural plasticity throughout life. In particular, the localization of PSA-NCAM in TG primary sensory neurons likely to be involved in the transmission of protopathic stimuli suggests the possible participation of this molecule in the processing of the relevant sensory neurotransmission.</p

TRPV1-Like Immunoreactivity in the Human Locus K, a Distinct Subregion of the Cuneate Nucleus

The presence of transient receptor potential vanilloid type-1 receptor (TRPV1)-like immunoreactivity (LI), in the form of nerve fibres and terminals, is shown in a set of discrete gray matter subregions placed in the territory of the human cuneate nucleus. We showed previously that those subregions share neurochemical and structural features with the protopathic nuclei and, after the ancient name of our town, collectively call them Locus Karalis, and briefly Locus K. TRPV1-LI in the Locus K is codistributed, though not perfectly overlapped, with that of the neuropeptides calcitonin gene-related peptide and substance P, the topography of the elements immunoreactive to the three markers, in relation to each other, reflecting that previously described in the caudal spinal trigeminal nucleus. Myelin stainings show that myelinated fibres, abundant in the cuneate, gracile and trigeminal magnocellular nuclei, are scarce in the Locus K as in the trigeminal substantia gelatinosa. Morphometric analysis shows that cell size and density of Locus K neurons are consistent with those of the trigeminal substantia gelatinosa and significantly different from those of the magnocellular trigeminal, solitary and dorsal column nuclei. We propose that Locus K is a special component of the human dorsal column nuclei. Its functional role remains to be determined, but TRPV1 appears to play a part in it

Proceedings of the 24th National Congress of the “Gruppo Italiano per lo Studio della Neuromorfologia” G.I.S.N., Bologna, November 28-29, 2014

Proceedings of the 24th National Congress of the “Gruppo Italiano per lo Studio della Neuromorfologia” G.I.S.N., Bologna, November 28-29, 201