Nitric oxide plays a crucial role in multiple physiological processes in salivary glands, yet its precise cellular sources in human glandular tissues remain insufficiently characterized. This study investigated the distribution and subcellular localization of neuronal nitric oxide synthase (nNOS) in human parotid and submandibular gland tissue samples obtained from surgical biopsies and autopsies, using both light and electron-microscope immunohistochemistry. In both gland types, nNOS was consistently observed in serous secretory cells and the ductal epithelium, whereas mucous cells showed no immunoreactivity. Ductal cell staining was heterogeneous, with some cells displaying intense labeling and others remaining unstained. Nerve fibers containing the enzyme were rare within the gland parenchyma. Ultrastructural analysis revealed the enzyme within secretory granules and small cytoplasmic vesicles of serous cells, as well as in the apical and basal cytoplasm, mitochondria, and nuclei of ductal epithelial cells. These findings provide the first ultrastructural evidence of nNOS in secretory and ductal cells of human major salivary glands. The selective localization in serous cells, absence in mucous cells, and limited nitrergic innervation suggest a substantial parenchymal contribution to nitric oxide production. This distribution indicates that nitric oxide regulates saliva formation, composition, and intracellular signaling and could play a broader role in oral physiology and disease.

Previous research has demonstrated that the transient bilateral common carotid artery occlusion and reperfusion (BCCAO/R) effectively models early brain inflammation resulting from sudden hypoperfusion and subsequent reperfusion. According to studies showing that diet and nutrition strongly influence brain neuroplasticity, in this study we evaluated whether kaempferol (KAM), a dietary flavonoid, offers neuroprotection in a rat BCCAO/R model. Adult Wistar rats were gavage fed a single dose of KAM (40 mg) six hours before surgery. Comprehensive lipidomic and molecular analyses were conducted on samples from the frontal and temporal-occipital cortices, as well as the plasma. In the frontal cortex, KAM elevated anti-inflammatory N-acylethanolamines palmitoylethanolamide (PEA), oleoylethanolamide (OEA), and docosahexaenoylethanolamide (DHAEA) and reduced oxidized arachidonic acid metabolites. KAM also downregulated cyclooxygenase- 2 (COX-2) protein and selectively decreased the endocannabinoid 2-arachidonoylglycerol (2-AG), showing a shift in AA metabolism. These molecular changes correlated with increased levels of peroxisome proliferator-activated receptor alpha (PPARα) and cannabinoid receptors CB1R and CB2R, supporting activation of both nuclear and membrane-bound anti-inflammatory pathways. No significant changes were observed in the temporal-occipital cortex. In plasma, DHAEA levels increased similarly to those in the cortex. However, rises in PEA and OEA were detected only in sham-operated KAM-treated animals, suggesting possible central redistribution under hypoperfusion/reperfusion stress. In summary, these findings demonstrate that KAM exerts dual anti-inflammatory effects by inhibiting COX-2-mediated prostanoid synthesis and promoting PPARα-driven lipid signaling. This dual mechanism highlights the potential of KAM as a dietary intervention to reduce neuroinflammation associated with hypoperfusion–reperfusion challenges.

The pulvinar, the largest thalamic nucleus, is a highly interconnected structure supporting perception, visuospatial attention, and emotional processing. Such a central role relies on a precise topographical organization reflected in anatomical connectivity and neurochemical markers. Traditionally subdivided into distinct subnuclei, recent work shows that these divisions only partially explain its organization, which is better captured by continuous gradients of cortical connections along dorso-ventral and medio-lateral axes. While well studied in primates, this gradient-based architecture remains less explored in humans. The present work combines high-quality, multimodal structural and functional imaging with a whole-brain, large-scale, PET atlas mapping 19 neurotransmitter systems. By applying diffusion embedding to tractography, functional connectivity, and receptor coexpression, we identify multiple gradients of structural connections, functional coactivation, and molecular binding patterns. These converge on a shared representation along the dorso-ventral and medio-lateral axes of the human pulvinar, aligning with connectivity transitions from lower-level to higher-order cortical regions. Moreover, this is paralleled by gradual changes in the expression of molecular markers associated with key neuromodulator systems, including serotoninergic, noradrenergic, dopaminergic, and opioid systems. Our findings advance the understanding of pulvinar anatomy and function, offering an exploratory framework to investigate the role of this structure in both health and disease.

BACKGROUND AND AIMS:Oxaliplatin (OHP) induced peripheral neurotoxicity (OIPN) is a complex spectrum comprising an acute and a chronic form. Acute OIPN leads to unpleasant transient sensations in the 24-72 h after chemotherapy, due to a temporary dysfunction in ion channels (i.e., axonal hyperexcitability in the absence of anatomical damage). Whereas chronic OIPN is characterized by painful manifestations. Literature data showed that a more pronounced acute OIPN could be an early predictor of chronic OIPN; thus, acute OIPN is becoming a possible target to prevent chronic OIPN. We went back to the bench side to characterize the complexity of painful phenomena experienced by OHP-treated patients. METHODS:Female OHP-treated (3 mg/Kg, 2qwx4ws, iv) and control rats (n = 10/group) were studied. Acute OIPN was detected via nerve excitability testing (NET), whereas chronic OIPN was assessed via behavioral tests, nerve conduction studies (NCS), and neuropathology (including immunohistochemistry on lumbar spinal cord specimens) both at the end of the full chemotherapy treatment (4 weeks) and at 6 weeks of follow-up. NET was also performed 1 week after treatment completion. RESULTS:NET alterations related to acute OIPN were resolved within a week after chemotherapy. Whereas, chronic OIPN encountered only partial recovery over time, with prominent small fiber damage. Immunolabeling of the spinal cord at the end of treatment and after the follow-up period was consistent with persistent neuropathic pain. INTERPRETATION:Our data supports the statement that unpleasant manifestations due to acute and chronic OIPN mirror different underlying phenomena and assessment as two separate entities should be considered in both clinical and preclinical studies.

The use of synthetic cannabinoid receptor agonists (SCRAs) represents a public health concern. Besides abuse liability and cognitive impairments, SCRAs consumption is associated with serious medical consequences in humans, including cardiotoxicity. The precise mechanisms underlying cardiac or other toxicities induced by SCRAs are not well understood. Here, we used in silico, in vivo, and ex vivo approaches to investigate the toxicological consequences induced by exposure to the SCRA JWH-018. Along with in silico predictive toxicological screening of 36 SCRAs by MC4PC software, adult male Sprague-Dawley rats were repeatedly exposed to JWH018 (0.25 mg/kg ip) for 14 consecutive days, with body temperature and cardiovascular parameters measured over the course of treatment. At 1 and 7 days after JWH-018 discontinuation, multiorgan tissue pathologies and heart mitochondria bioenergetics were assessed. The in silico findings predicted risk of cardiac adverse effects specifically for JWH-018 and other aminoalkylindole SCRAs (i.e., electrocardiogram abnormality and QT prolongation). The results from rats revealed that repeated, but not single, JWH-018 exposure induced hypothermia and cardiovascular stimulation (e.g., increased blood pressure and heart rate) which persisted throughout treatment. Post-mortem findings demonstrated cardiac lesions (i.e., vacuolization, waving, edema) 1 day after JWH-018 discontinuation, which may contribute to lung, kidney, and liver tissue degeneration observed 7 days later. Importantly, repeated JWH-018 exposure induced mitochondrial dysfunction in cardiomyocytes, i.e., defective lipid OXPHOS, which may represent one mechanism of JWH-018-induced toxicity. Our results demonstrate that repeated administration of even a relatively low dose of JWH-018 is sufficient to affect cardiovascular function and induce enduring toxicological consequences, pointing to risks associated with SCRA consumption.

BackgroundWhat textbooks usually call the sublingual gland in humans is in reality a tissue mass of two types of salivary glands, the anteriorly located consisting of a cluster of minor sublingual glands and the posteriorly located major sublingual gland with its outlet via Bartholin’s duct. Only recently, the adrenergic and cholinergic innervations of the major sublingual gland was reported, while information regarding the neuropeptidergic and nitrergic innervations is still lacking.MethodsBioptic and autoptic specimens of the human major sublingual gland were examined by means of immunohistochemistry for the presence of vasoactive intestinal peptide (VIP)-, neuropeptide Y (NPY)-, substance P (SP)-, calcitonin gene related-peptide (CGRP)-, and neuronal nitric oxide synthase (nNOS)-labeled neuronal structures.ResultsAs to the neuropeptidergic innervation of secretory cells (here in the form of mucous tubular and seromucous cells), the findings showed many VIP-containing nerves, few NPY- and SP-containing nerves and a lack of CGRP-labeled nerves. As to the neuropeptidergic innervation of vessels, the number of VIP-containing nerves was modest, while, of the other neuropeptide-containing nerves under study, only few (SP and CGRP) to very few (NPY) nerves were observed. As to the nitrergic innervation, nNOS-containing nerves were very few close to secretory cells and even absent around vessels.ConclusionThe various innervation patterns may suggest potential transmission mechanisms involved in secretory and vascular responses of the major sublingual gland.

A growing body of evidence indicates that the practice of consuming alcohol mixed with energy drinks (ED) (AMED) in a binge drinking pattern is significantly diffusing among the adolescent population. This behavior, aimed at increasing the intake of alcohol, raises serious concerns about its long-term effects. Epidemiological studies suggest that AMED consumption might increase vulnerability to alcohol abuse and have a gating effect on the use of illicit drugs. The medial prefrontal cortex (mPFC) is involved in the modulation of the reinforcing effects of alcohol and of impulsive behavior and plays a key role in the development of addiction. In our study, we used a binge-like protocol of administration of alcohol, ED, or AMED in male adolescent rats, to mimic the binge-like intake behavior observed in humans, in order to evaluate whether these treatments could differentially affect the function of mesocortical dopaminergic neurons in adulthood. We did so by measuring: i) physiological sensorimotor gating; ii) voluntary alcohol consumption and dopamine transmission before, during, and after presentation of alcohol; iii) electrophysiological activity of VTA dopaminergic neurons and their sensitivity to a challenge with alcohol. Our results indicate that exposure to alcohol, ED, or AMED during adolescence induces differential adaptive changes in the function of mesocortical dopaminergic neurons and, in particular, that AMED exposure decreases their sensitivity to external stimuli, possibly laying the foundation for the altered behaviors observed in adulthood.

In the last decades, the consumption of energy drinks has risen dramatically, especially among young people, adolescents and athletes, driven by the constant search for ergogenic effects, such as the increase in physical and cognitive performance. In parallel, mixed consumption of energy drinks and ethanol, under a binge drinking modality, under a binge drinking modality, has similarly grown among adolescents. However, little is known whether the combined consumption of these drinks, during adolescence, may have long-term effects on central function, raising the question of the risks of this habit on brain maturation. Our study was designed to evaluate, by behavioral, electrophysiological and molecular approaches, the long-term effects on hippocampal plasticity of ethanol (EtOH), energy drinks (EDs), or alcohol mixed with energy drinks (AMED) in a rat model of binge-like drinking adolescent administration. The results show that AMED binge-like administration produces adaptive hippocampal changes at the molecular level, associated with electrophysiological and behavioral alterations, which develop during the adolescence and are still detectable in adult animals. Overall, the study indicates that binge-like drinking AMED adolescent exposure represents a habit that may affect permanently hippocampal plasticity.

The stress-induced alterations in cognitive processes and psychiatric disorders can be accelerated when acute stressors challenge the hippocampal functions. To address this issue, we used Western Blot (WB) and immunohistochemistry assays to investigate the impact of acute forced swimming (FS) on the expression of the CB1 cannabinoid receptors (CB1R) in the hippocampus (HC) of the male outbred Roman High- (RHA) and Low-Avoidance (RLA) rat lines, one of the most validated genetic models for the study of behavior related to fear/anxiety and stress-induced depression. The distinct responses to FS confirmed the different behavioral strategies displayed by the two phenotypes when exposed to stressors, with RLA and RHA rats displaying reactive vs. proactive coping, respectively. In control rats, the WB analysis showed lower hippocampal CB1R relative levels in RLA rats than in their RHA counterparts. After FS, RLA rats showed increased CB1R levels in the dorsal HC (dHC) vs. no change in the ventral HC (vHC), while RHA rats displayed no change in the dHC vs. a decrease in the vHC. In the tissue sections from dHC, FS elicited an increment over the control level of CB1R-like immunoreactivity (LI) in the CA1 and CA3 sectors of the Ammon's horn of RLA rats, while in RHA rats the density of CB1R-LI increased only in the CA1 sector. In tissue sections from the vHC, FS caused an increase over the control values of CB1R-LI only in the CA1 sector of RLA rats and a decrement of the CB1R-LI in the CA1 sector and dentate gyrus of control RHA rats. This study shows for the first time that, in baseline conditions, the CB1Rs are present in the dHC and the vHC of the Roman rat lines with a different distribution along the septo-temporal extension of the HC and that the FS induces rapid and distinct changes in the hippocampal expression of CB1R of RLA vs. RLA rats, in keeping with the view that endocannabinoid signaling may contribute to the molecular mechanisms that regulate the different responses of the dHC vs. the vHC to aversive situations in male Roman rats. Our results also provide evidence supporting the involvement of CB1R in the molecular underpinnings of the susceptibility of RLA rats and the resistance of RHA rats to stress-induced depression-like behavior.

In this article, we describe the effects of tail pinch (TP), a mild acute stressor, on the levels of brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor B (trkB) proteins in the hippocampus (HC) of the outbred Roman High- (RHA) and Low-Avoidance (RLA) rats, one of the most validated genetic models for the study of fear/anxiety- and stress-related behaviors. Using Western blot (WB) and immunohistochemistry assays, we show for the first time that TP induces distinct changes in the levels of BDNF and trkB proteins in the dorsal (dHC) and ventral (vHC) HC of RHA and RLA rats. The WB assays showed that TP increases BDNF and trkB levels in the dHC of both lines but induces opposite changes in the vHC, decreasing BDNF levels in RHA rats and trkB levels in RLA rats. These results suggest that TP may enhance plastic events in the dHC and hinder them in the vHC. Immunohistochemical assays, carried out in parallel to assess the location of changes revealed by the WB, showed that, in the dHC, TP increases BDNF-like immunoreactivity (LI) in the CA2 sector of the Ammon’s horn of both Roman lines and in the CA3 sector of the Ammon’s horn of RLA rats while, in the dentate gyrus (DG), TP increases trkB-LI in RHA rats. In contrast, in the vHC, TP elicits only a few changes, represented by decreases of BDNF- and trkB-LI in the CA1 sector of the Ammon’s horn of RHA rats. These results support the view that the genotypic/phenotypic features of the experimental subjects influence the effects of an acute stressor, even as mild as TP, on the basal BDNF/trkB signaling, leading to different changes in the dorsal and ventral subdivisions of the HC.

Sickle cell disease (SCD) is caused by the homozygous beta-globin gene mutation that can lead to ischemic multi-organ damage and consequently reduce life expectancy. On the other hand, sickle cell trait (SCT), the heterozygous beta-globin gene mutation, is still considered a benign condition. Although the mechanisms are not well understood, clinical evidence has recently shown that specific pathological symptoms can also be recognized in SCT carriers. So far, there are still scant data regarding the morphological modifications referable to possible multi-organ damage in the SCT condition. Therefore, after genotypic and hematological characterization, by conventional light microscopy and transmission electron microscopy (TEM), we investigated the presence of tissue alterations in 13 heterozygous Townes mice, one of the best-known animal models that, up to now, was used only for the study of the homozygous condition. We found that endothelial alterations, as among which the thickening of vessel basal lamina, are ubiquitous in the lung, liver, kidney, and spleen of SCT carrier mice. The lung shows the most significant alterations, with a distortion of the general tissue architecture, while the heart is the least affected. Collectively, our findings contribute novel data to the histopathological modifications at microscopic and ultrastructural levels, underlying the heterozygous beta-globin gene mutation, and indicate the translational suitability of the Townes model to characterize the features of multiple organ involvement in the SCT carriers.

The human subthalamic area is a region of high anatomical complexity, tightly packed with tiny fiber bundles. Some of them, including the pallidothalamic, cerebello-thalamic, and mammillothalamic tracts, are relevant targets in functional neurosurgery for various brain diseases. Diffusion-weighted imaging-based tractography has been suggested as a useful tool to map white matter pathways in the human brain in vivo and non-invasively, though the reconstruction of these specific fiber bundles is challenging due to their small dimensions and complex anatomy. To the best of our knowledge, a population-based, in vivo probabilistic atlas of subthalamic white matter tracts is still missing. In the present work, we devised an optimized tractography protocol for reproducible reconstruction of the tracts of subthalamic area in a large data sample from the Human Connectome Project repository. First, we leveraged the super-resolution properties and high anatomical detail provided by short tracks track-density imaging (stTDI) to identify the white matter bundles of the subthalamic area on a group-level template. Tracts identification on the stTDI template was also aided by visualization of histological sections of human specimens. Then, we employed this anatomical information to drive tractography at the subject-level, optimizing tracking parameters to maximize between-subject and within-subject similarities as well as anatomical accuracy. Finally, we gathered subject level tracts reconstructed with optimized tractography into a large-scale, normative population atlas. We suggest that this atlas could be useful in both clinical anatomy and functional neurosurgery settings, to improve our understanding of the complex morphology of this important brain region.

The present work was undertaken to investigate the effects of acute forced swimming (FS) on the levels of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (trkB) proteins in: the ventral tegmental area (VTA); the nucleus accumbens (Acb) shell and core compartments; and the anterior cingulate (ACg), prelimbic (PL) and infralimbic (IL) territories of the prefrontal cortex of genetic models of vulnerability (RLA, Roman low-avoidance rats) and resistance (RHA, Roman high-avoidance rats) to stress-induced depression. We report for the first time that FS induced very rapid and distinct changes in the levels of BDNF and trkB proteins in different areas of the mesocorticolimbic system of RHA and RLA rats. Thus, (1) in the VTA and Acb core, FS elicited a significant increase of both BDNF- and trkB-LI in RHA but not RLA rats, whereas in the Acb shell no significant changes in BDNF- and trkB-LI across the line and treatment were observed; (2) in RLA rats, the basal levels of BDNF-LI in the IL/PL cortex and of trkB-LI in the ACg cortex were markedly lower than those of RHA rats; moreover, BDNF- and trkB-LI in the IL/PL and ACg cortex were increased by FS in RLA rats but decreased in their RHA counterparts. These results provide compelling evidence that the genetic background influences the effects of stress on BDNF/trkB signaling and support the view that the same stressor may impact differently on the expression of BDNF in discrete brain areas.

Sexual activity causes differential changes in the expression of markers of neural activation (c-Fos and ΔFosB) and neural plasticity (Arc and BDNF/trkB), as determined either by Western Blot (BDNF, trkB, Arc, and ΔFosB) or immunohistochemistry (BDNF, trkB, Arc, and c-Fos), in the hippocampus of male Roman high (RHA) and low avoidance (RLA) rats, two psychogenetically selected rat lines that display marked differences in sexual behavior (RHA rats exhibit higher sexual motivation and better copulatory performance than RLA rats). Both methods showed (with some differences) that sexual activity modifies the expression levels of these markers in the hippocampus of Roman rats depending on: (i) the level of sexual experience, that is, changes were usually more evident in sexually naïve than in experienced rats; (ii) the hippocampal partition, that is, BDNF and Arc increased in the dorsal but tended to decrease in the ventral hippocampus; (iii) the marker considered, that is, in sexually experienced animals BDNF, c-Fos, and Arc levels were similar to those of controls, while ΔFosB levels increased; and (iv) the rat line, that is, changes were usually larger in RHA than RLA rats. These findings resemble those of early studies in RHA and RLA rats showing that sexual activity influences the expression of these markers in the nucleus accumbens, medial prefrontal cortex, and ventral tegmental area, and show for the first time that also in the hippocampus sexual activity induces neural activation and plasticity, events that occur mainly during the first phase of the acquisition of sexual experience and depend on the genotypic/phenotypic characteristics of the animals.

To contribute to the knowledge of the autonomic innervation in liver regeneration, here we investigate the distribution of tyrosine hydroxylase (TH)- and choline acetyltransferase (ChAT)-like immunoreactive (LI) nerve fibers, to indicate noradrenergic and cholinergic nerves, respectively, in rats under different conditions of liver damage and repair. By immunohistochemistry and assessment of nerve fiber density, three models of induced hepatic regeneration were examined: the carbon tetrachloride (CCl4) intoxication, with two treatment periods of 14 weeks and 18 weeks; the partial hepatectomy (PH); the thyroid hormone (T3) treatment. TH- and ChAT-LI nerve fibers were detectable mostly in the portal spaces, the TH-LI ones occurring only around blood vessels while the ChAT-LI nerve fibers were also associated with secretory ducts. The density of TH-like immunoreactivity in the portal areas decreased after the CCl4 14 weeks treatment and PH and increased after T3. By contrast, ChAT-LI nerve fibers appeared particularly abundant around the neoductal elements in the CCl4 rats and were rare to absent in the PH and T3-treated groups. The ChAT-LI nerve fiber density within the portal areas revealed an increase in the CCl4-treated rats while showing no change in the PH and T3-treated rats. The changes in the density of perivascular TH- and ChAT-containing nerve fibers suggest a finely tuned autonomic modulation of hepatic blood flow depending on the type of subacute/chronic induced hyperplasia, while the characteristic occurrence of the periductal cholinergic innervation after the CCl4 treatment implies a selective parasympathetic role in regulating the physiopathological regenerative potential of the rat liver.

We have previously shown that bilateral common carotid artery occlusion followed by reperfusion (BCCAO/R) is a model to study early hypoperfusion/reperfusion-induced changes in biomarkers of the tissue physiological response to oxidative stress and inflammation. Thus in this study, we investigate with immunochemical assays if a single dose of beta-caryophyllene (BCP), administered before the BCCAO/R, can modulate the TRPV1, BDNF, and trkB receptor in the brain cortex; the glial markers GFAP and Iba1 were also examined. Frontal and temporal-occipital cortical regions were analyzed in two groups of male rats, sham-operated and submitted to BCCAO/R. Six hours before surgery, one group was gavage fed a dose of BCP (40 mg/per rat in 300 μL of sunflower oil), the other was pre-treated with the vehicle alone. Western blot analysis showed that, in the frontal cortex of vehicle-treated rats, the BCCAO/R caused a TRPV1 decrease, an increment of trkB and GFAP, no change in BDNF and Iba1. The BCP treatment caused a decrease of BDNF and an increase of trkB levels in both sham and BCCAO/R conditions while inducing opposite changes in the case of TRPV1, whose levels became higher in BCCAO/R and lower in sham conditions. Present results highlight the role of BCP in modulating early events of the cerebral inflammation triggered by the BCCAO/R through the regulation of TRPV1 and the BDNF-trkB system.