-
Reviews in the Neurosciences Oct 2023Since the 1950s study of Scoville and Milner on the case H.M., the hippocampus has attracted neuroscientists' attention. The hippocampus has been traditionally divided... (Review)
Review
Since the 1950s study of Scoville and Milner on the case H.M., the hippocampus has attracted neuroscientists' attention. The hippocampus has been traditionally divided into dorsal and ventral parts, each of which projects to different brain structures and mediates various functions. Despite a predominant interest in its dorsal part in animal models, especially regarding episodic-like and spatial cognition, recent data highlight the role of the ventral hippocampus (vHPC), as the main hippocampal output, in cognitive processes. Here, we review recent studies conducted in rodents that have used advanced functional techniques to specifically monitor and manipulate vHPC efferent pathways and delineate the roles of these specific projections in learning and memory processes. Results highlight that vHPC projections to basal amygdala are implicated in emotional memory, to nucleus accumbens in social memory and instrumental actions and to prefrontal cortex in all the above as well as in object-based memory. Some of these hippocampal projections also modulate feeding and anxiety-like behaviours providing further evidence that the "one pathway-one function" view is outdated and future directions are proposed to better understand the role of hippocampal pathways and shed further light on its connectivity and function.
Topics: Animals; Humans; Hippocampus; Nucleus Accumbens; Prefrontal Cortex; Learning; Cognition; Neural Pathways
PubMed: 37192533
DOI: 10.1515/revneuro-2023-0009 -
Updates in Surgery Aug 2023Primary and incisional ventral hernias are significant public health issues for their prevalence, variability of professional practices, and high costs associated with... (Review)
Review
Primary and incisional ventral hernias are significant public health issues for their prevalence, variability of professional practices, and high costs associated with the treatment In 2019, the Board of Directors of the Italian Society for Endoscopic Surgery (SICE) promoted the development of new guidelines on the laparoscopic treatment of ventral hernias, according to the new national regulation. In 2022, the guideline was accepted by the government agency, and it was published, in Italian, on the SNLG website. Here, we report the adopted methodology and the guideline's recommendations, as established in its diffusion policy. This guideline is produced according to the methodology indicated by the SNGL and applying the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Fifteen recommendations were produced as a result of 4 PICO questions. The level of recommendation was conditional for 12 of them and conditional to moderate for one. This guideline's strengths include relying on an extensive systematic review of the literature and applying a rigorous GRADE method. It also has several limitations. The literature on the topic is continuously and rapidly evolving; our results are based on findings that need constant re-appraisal. It is focused only on minimally invasive techniques and cannot consider broader issues (e.g., diagnostics, indication for surgery, pre-habilitation).
Topics: Humans; Herniorrhaphy; Surgical Mesh; Hernia, Ventral; Incisional Hernia; Laparoscopy
PubMed: 37217637
DOI: 10.1007/s13304-023-01534-3 -
BioRxiv : the Preprint Server For... Jul 2023The hippocampus , as well as dopamine circuits , coordinate decision-making in anxiety-eliciting situations. Yet, little is known about how dopamine modulates...
The hippocampus , as well as dopamine circuits , coordinate decision-making in anxiety-eliciting situations. Yet, little is known about how dopamine modulates hippocampal representations of emotionally-salient stimuli to inform appropriate resolution of approach avoidance conflicts. We here study dopaminoceptive neurons in mouse ventral hippocampus (vHipp), molecularly distinguished by their expression of dopamine D1 or D2 receptors. We show that these neurons are transcriptionally distinct and topographically organized across vHipp subfields and cell types. In the ventral subiculum where they are enriched, both D1 and D2 neurons are recruited during anxiogenic exploration, yet with distinct profiles related to investigation and behavioral selection. In turn, they mediate opposite approach/avoidance responses, and are differentially modulated by dopaminergic transmission in that region. Together, these results suggest that vHipp dopamine dynamics gate exploratory behaviors under contextual uncertainty, implicating dopaminoception in the complex computation engaged in vHipp to govern emotional states.
PubMed: 37546856
DOI: 10.1101/2023.07.25.550554 -
Annual Review of Vision Science Sep 2023Perception and memory are traditionally thought of as separate cognitive functions, supported by distinct brain regions. The canonical perspective is that perceptual... (Review)
Review
Perception and memory are traditionally thought of as separate cognitive functions, supported by distinct brain regions. The canonical perspective is that perceptual processing of visual information is supported by the ventral visual stream, whereas long-term declarative memory is supported by the medial temporal lobe. However, this modular framework cannot account for the increasingly large body of evidence that reveals a role for early visual areas in long-term recognition memory and a role for medial temporal lobe structures in high-level perceptual processing. In this article, we review relevant research conducted in humans, nonhuman primates, and rodents. We conclude that the evidence is largely inconsistent with theoretical proposals that draw sharp functional boundaries between perceptual and memory systems in the brain. Instead, the weight of the empirical findings is best captured by a representational-hierarchical model that emphasizes differences in content, rather than in cognitive processes within the ventral visual stream and medial temporal lobe.
Topics: Animals; Humans; Temporal Lobe; Recognition, Psychology; Brain; Cognition; Perception
PubMed: 37068791
DOI: 10.1146/annurev-vision-120222-014200 -
Frontiers in Immunology 2023Encephalitis is a devastating neurologic disorder with high morbidity and mortality. Autoimmune causes are roughly as common as infectious ones. N-methyl-D-aspartic acid...
BACKGROUND AND OBJECTIVES
Encephalitis is a devastating neurologic disorder with high morbidity and mortality. Autoimmune causes are roughly as common as infectious ones. N-methyl-D-aspartic acid receptor (NMDAR) encephalitis (NMDARE), characterized by serum and/or spinal fluid NMDAR antibodies, is the most common form of autoimmune encephalitis (AE). A translational rodent NMDARE model would allow for pathophysiologic studies of AE, leading to advances in the diagnosis and treatment of this debilitating neuropsychiatric disorder. The main objective of this work was to identify optimal active immunization conditions for NMDARE in mice.
METHODS
Female C57BL/6J mice aged 8 weeks old were injected subcutaneously with an emulsion of complete Freund's adjuvant, killed and dessicated , and a 30 amino acid peptide flanking the NMDAR GluN1 subunit N368/G369 residue targeted by NMDARE patients' antibodies. Three different induction methods were examined using subcutaneous injection of the peptide emulsion mixture into mice in 1) the ventral surface, 2) the dorsal surface, or 3) the dorsal surface with reimmunization at 4 and 8 weeks (boosted). Mice were bled biweekly and sacrificed at 2, 4, 6, 8, and 14 weeks. Serum and CSF NMDAR antibody titer, mouse behavior, hippocampal cell surface and postsynaptic NMDAR cluster density, and brain immune cell entry and cytokine content were examined.
RESULTS
All immunized mice produced serum and CSF NMDAR antibodies, which peaked at 6 weeks in the serum and at 6 (ventral and dorsal boosted) or 8 weeks (dorsal unboosted) post-immunization in the CSF, and demonstrated decreased hippocampal NMDAR cluster density by 6 weeks post-immunization. In contrast to dorsally-immunized mice, ventrally-induced mice displayed a translationally-relevant phenotype including memory deficits and depressive behavior, changes in cerebral cytokines, and entry of T-cells into the brain at the 4-week timepoint. A similar phenotype of memory dysfunction and anxiety was seen in dorsally-immunized mice only when they were serially boosted, which also resulted in higher antibody titers.
DISCUSSION
Our study revealed induction method-dependent differences in active immunization mouse models of NMDARE disease. A novel ventrally-induced NMDARE model demonstrated characteristics of AE earlier compared to dorsally-induced animals and is likely suitable for most short-term studies. However, boosting and improving the durability of the immune response might be preferred in prolonged longitudinal studies.
Topics: Mice; Female; Animals; Emulsions; Mice, Inbred C57BL; Encephalitis; Antibodies; Receptors, N-Methyl-D-Aspartate; Vaccination; Disease Models, Animal; Autoimmune Diseases of the Nervous System
PubMed: 37520559
DOI: 10.3389/fimmu.2023.1177672 -
Bioactive Materials Sep 2023Transplanting human neural progenitor cells is a promising method of replenishing the lost neurons after spinal cord injury (SCI), but differentiating neural progenitor...
Transplanting human neural progenitor cells is a promising method of replenishing the lost neurons after spinal cord injury (SCI), but differentiating neural progenitor cells into the diverse types of mature functional spinal cord neurons is challenging. In this study, engineered human embryonic spinal cord-like tissues with dorsal and ventral neuronal characters (DV-SC) were generated by inducing human neural progenitor cells (hscNPCs) to differentiate into various types of dorsal and ventral neuronal cells on collagen scaffold . Transplantation of DV-SC into complete SCI models in rats and monkeys showed better therapeutic effects than undifferentiated hscNPCs, including pronounced cell survival and maturation. DV-SC formed a targeted connection with the host's ascending and descending axons, partially restored interrupted neural circuits, and improved motor evoked potentials and the hindlimb function of animals with SCI. This suggests that the transplantation of pre-differentiated hscNPCs with spinal cord dorsal and ventral neuronal characteristics could be a promising strategy for SCI repair.
PubMed: 37064803
DOI: 10.1016/j.bioactmat.2023.03.015 -
Chirurgia (Bucharest, Romania : 1990) Aug 2023While ventral hernia repair is a frequent surgical intervention, the possibility of complications remains present. The use of drains to mitigate complications is a... (Observational Study)
Observational Study
While ventral hernia repair is a frequent surgical intervention, the possibility of complications remains present. The use of drains to mitigate complications is a topic of debate, with conflicting evidence. This study aimed to evaluate the association between drain usage and postoperative complications in ventral hernia repair. A single-center prospective study included patients undergoing ventral hernia repair from 2018 to 2022. Patient data and surgical techniques were recorded. Statistical analysis was performed to assess risk factors for drain insertion and complications. Of the 216 patients included, 19.44% had diabetes, and 20% had cancer. Postoperative complications (Clavien Dindo grade IIIB) occurred in 9.3% of cases, resulting in a 3.7% mortality. Decision factors for drain insertion included older age, larger hernia size, bowel resection with anastomosis, emergency setting and the need for adhesiolysis. No differences were found between the two groups regarding seroma and hematoma formation and mesh infection. Patients with drains had a longer hospital stay and higher costs. Conclusion: The decision to use drains in ventral hernia repair was influenced by surgical complexity factors rather than patient characteristics. While drain usage did not correlate with postoperative morbidities, it was associated with longer hospitalization and higher costs. Individualized decision-making is crucial to balance complications and resource utilization in ventral hernia repair.
Topics: Humans; Prospective Studies; Treatment Outcome; Drainage; Postoperative Complications; Hernia, Ventral
PubMed: 37698005
DOI: 10.21614/chirurgia.2023.v.118.i.4.p.426 -
Obesity (Silver Spring, Md.) Sep 2023This case-control study was aimed at testing two main hypotheses: (i) obesity is characterized by neurofunctional alterations within the mesocorticolimbic reward system,...
OBJECTIVE
This case-control study was aimed at testing two main hypotheses: (i) obesity is characterized by neurofunctional alterations within the mesocorticolimbic reward system, a brain network originating from the midbrain ventral tegmental area (VTA); and (ii) these alterations are associated with a bias for food-related stimuli and craving.
METHODS
Normal-weight individuals and individuals with obesity underwent a resting-state functional magnetic resonance imaging scan and the assessment of impulsivity, food craving, appetite, and implicit bias for food and non-food stimuli. The VTA was used as a seed to map, for each participant, the strength of its functional connections with the rest of the brain. The between-group difference in functional connectivity was then computed, and brain-behavior correlations were performed.
RESULTS
Individuals with obesity showed hyper-connectivity of the VTA with part of the ventral occipitotemporal cortex, recently found to be specialized for food images, and hypo-connectivity with the left inferior frontal gyrus, devoted to cognitive control. VTA-ventral occipitotemporal cortex connectivity was positively associated with food craving and food-related bias; the reverse correlation was observed for VTA-inferior frontal gyrus connectivity.
CONCLUSIONS
These findings reveal that, in obesity, food-related visual stimuli become cravingly salient through an imbalanced connectivity of the reward system with sensory-specific regions and the frontal cortex involved in cognitive control.
Topics: Humans; Case-Control Studies; Food; Brain; Cerebral Cortex; Obesity
PubMed: 37605635
DOI: 10.1002/oby.23834