Search results for "Neuropeptide"

Profilin 1 is required for peripheral nervous system myelination

2014

Myelination allows rapid saltatory propagation of action potentials along the axon and is an essential prerequisite for the normal functioning of the nervous system. During peripheral nervous system (PNS) development, myelin-forming Schwann cells (SCs) generate radial lamellipodia to sort and ensheath axons. This process requires controlled cytoskeletal remodeling, and we show that SC lamellipodia formation depends on the function of profilin 1 (Pfn1), an actin-binding protein involved in microfilament polymerization. Pfn1 is inhibited upon phosphorylation by ROCK, a downstream effector of the integrin linked kinase pathway. Thus, a dramatic reduction of radial lamellipodia formation is obs…

Nucleus incertus—An emerging modulatory role in arousal, stress and memory

2011

A major challenge in systems neuroscience is to determine the underlying neural circuitry and associated neurotransmitters and receptors involved in psychiatric disorders, such as anxiety and depression. A focus of many of these studies has been specific brainstem nuclei that modulate levels of arousal via their ascending monoaminergic projections (e.g. the serotonergic dorsal raphe, noradrenergic locus ceruleus and cholinergic laterodorsal tegmental nucleus). After years of relative neglect, the subject of recent studies in this context has been the GABAergic nucleus incertus,1 which is located in the midline periventricular central gray in the ‘prepontine’ hindbrain, with broad projection…

EFFECT OF ACETALDEHYDE INTOXICATION AND WITHDRAWAL ON NEUROPEPTIDE Y EXPRESSION. FOCUS ON CB1 RECEPTOR ROLE.

2014

Neuropeptide Y (NPY) acts as an endogenous anxiolytic, and, like endocannabinoids, plays an important role in the regulation of neuronal excitability during ethanol withdrawal (Rubio et al., 2011). Since acetaldehyde is considered a mediator of ethanol central effects, this research aims at investigating, following intoxication and during withdrawal, the effects of acetaldehyde on NPY expression in brain areas particularly vulnerable to alcohol, and the influence of cannabinoid system on it. Rats underwent acetaldehyde intoxication (450mg/kg, i.g., 4 times daily for 4 days); AM281, a CB1 selective antagonist (2,5 mg/kg, i.p.) was administered during abstinence. Immunohistochemical analysis …

Melanocortins: regulators of behavioural and neurochemical processes

2004

Characterization of somatostatin- and cholecystokinin-immunoreactive periglomerular cells in the rat olfactory bulb.

2005

Periglomerular cells (PG) are interneurons of the olfactory bulb (OB) that modulate the first synaptic relay of the olfactory information from the olfactory nerve to the dendrites of the bulbar principal cells. Previous investigations have pointed to the heterogeneity of these interneurons and have demonstrated the presence of two different types of PG. In the rat OB, type 1 PG receive synaptic contacts from the olfactory axons and are γ-aminobutyric acid (GABA)-ergic, whereas type 2 PG do not receive synaptic contacts from the olfactory axons and are GABA immunonegative. In this study, we analyze and characterize neurochemically a group of PG that has not been previously classified either …

The neuropeptide Pth2 modulates social behavior and anxiety in zebrafish

2021

SummaryAnimal behavior is strongly context-dependent and behavioral performance is often modulated by internal state. In particular, different social contexts can alter anxiety levels and modulate social behavior. The vertebrate-specific neuropeptide parathyroid hormone 2 (pth2) is directly regulated by the presence or absence of conspecifics in zebrafish. As its cognate receptor, the parathyroid hormone 2 receptor (pth2r), is widely expressed across the brain, we tested fish lacking the functional Pth2 peptide in several anxiety-related and social paradigms. Rodents lacking PTH2 display increased anxiety-related behavior. Here we show that the propensity to react to sudden stimuli with an …

Gastrin-cholecystokinin-like immunoreactivity in the central nervous system of the milkweed bug, Spilostethus pandurus. Ultrastructural aspects of th…

1995

Summary All the ganglia belonging to the central nervous system of adults of the milkweed bug Spilostethus pandurus (Hemiptera) were screened immunohistochemically for vertebrate gastrin-cholecystokinin (CCK-8(s))-like peptides. Several large reactive perikarya are present in the median part of the protocerebrum, their processes extending to the dorsal ‘aorta’. These cell bodies are also paraldehyde fuchsin-positive, ie they are A-type cells. In the lateral part of the protocerebrum, in the deutocerebrum and tritocerebrum, and in the suboesophageal, prothoracic and abdominal ganglia, a few immunoreactive cell bodies send axonal processes into their respective neuropiles. The A-type cells re…

Étude des mécanismes moléculaires associés aux effets de l'ODN sur des cellules astrogliales et microgliales soumises à un stress oxydant : impact su…

2019

Neurodegenerative diseases are characterized by oxidative stress associated with mitochondrial damages leading to neuronal cell death. To mitigate these damages and promote neuronal cytoprotection and neurogenesis, endogenous (Neuropeptide: octadecaneuropeptide (ODN)) or exogenous (Polyphenols: resveratrol (RSV) and apigenin (API)) natural neurotrophic factors could be used as therapeutic agents to promote neuronal differentiation of immature and pluripotent stem cells. ODN is a peptide produced by astrocytes and known as a powerful neuroprotective agent. It is therefore of interest of studying its effects on the mobilization of calcium, its ability to protect neuronal cells against apoptos…

Role of NK1 and NK2 receptors in mouse gastric mechanical activity

2006

The aim of the present study was to examine the role of NK1 and NK2 receptors in the control of mechanical activity of mouse stomach. In this view, the motor effects induced by NK1 and NK2 receptor agonists and antagonists were analyzed, measuring motility as intraluminal pressure changes in mouse-isolated stomach preparations. In parallel, immunohistochemical studies were performed to identify the location of NK1 and NK2 receptors on myenteric neurons and smooth muscle cells. Substance P (SP) induced biphasic effects: a contraction followed by relaxation; neurokinin A (NKA) and [β-Ala8]-NKA(4−10), selective agonist of NK2 receptors, evoked concentration-dependent contractions, whereas [Sar…

Progress in the characterization of insulin-like peptides in aphids: Immunohistochemical mapping of ILP4.

2021

Aphids were the first animals described as photoperiodic due to their seasonal switch from viviparous parthenogenesis to sexual reproduction (cyclical parthenogenesis) caused by the shortening of the photoperiod in autumn. This switch produces a single sexual generation of oviparous females and males that mate and lay diapausing cold-resistant eggs that can overcome the unfavourable environmental conditions typical of winter in temperate regions. Previous studies have hinted at a possible implication of two insulin-like peptides (ILP1 and ILP4) in the aphid seasonal response, changing their expression levels between different photoperiodic conditions. Moreover, in situ localization of their…