5-MeO-DMT induces sleep-like LFP spectral signatures in the hippocampus and prefrontal cortex of awake rats.

5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a potent classical psychedelic known to induce changes in locomotion, behaviour, and sleep in rodents. However, there is limited knowledge regarding its acute neurophysiological effects. Local field potentials (LFPs) are commonly used as a proxy for neural activity, but previous studies investigating psychedelics have been hindered by confounding effects of behavioural changes and anaesthesia, which alter these signals. To address this gap, we investigated acute LFP changes in the hippocampus (HP) and medial prefrontal cortex (mPFC) of freely behaving rats, following 5-MeO-DMT administration. 5-MeO-DMT led to an increase of delta power and a decrease of theta power in the HP LFPs, which could not be accounted for by changes in locomotion. Furthermore, we observed a dose-dependent reduction in slow (20-50 Hz) and mid (50-100 Hz) gamma power, as well as in theta phase modulation, even after controlling for the effects of speed and theta power. State map analysis of the spectral profile of waking behaviour induced by 5-MeO-DMT revealed similarities to electrophysiological states observed during slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. Our findings suggest that the psychoactive effects of classical psychedelics are associated with the integration of waking behaviours with sleep-like spectral patterns in LFPs.

Neurophysiological alterations in mice and humans carrying mutations in APP and PSEN1 genes.

BACKGROUND: Studies in animal models of Alzheimer's disease (AD) have provided valuable insights into the molecular and cellular processes underlying neuronal network dysfunction. Whether and how AD-related neurophysiological alterations translate between mice and humans remains however uncertain. METHODS: We characterized neurophysiological alterations in mice and humans carrying AD mutations in the APP and/or PSEN1 genes, focusing on early pre-symptomatic changes. Longitudinal local field potential recordings were performed in APP/PS1 mice and cross-sectional magnetoencephalography recordings in human APP and/or PSEN1 mutation carriers. All recordings were acquired in the left frontal cortex, parietal cortex, and hippocampus. Spectral power and functional connectivity were analyzed and compared with wildtype control mice and healthy age-matched human subjects. RESULTS: APP/PS1 mice showed increased absolute power, especially at higher frequencies (beta and gamma) and predominantly between 3 and 6 moa. Relative power showed an overall shift from lower to higher frequencies over almost the entire recording period and across all three brain regions. Human mutation carriers, on the other hand, did not show changes in power except for an increase in relative theta power in the hippocampus. Mouse parietal cortex and hippocampal power spectra showed a characteristic peak at around 8 Hz which was not significantly altered in transgenic mice. Human power spectra showed a characteristic peak at around 9 Hz, the frequency of which was significantly reduced in mutation carriers. Significant alterations in functional connectivity were detected in theta, alpha, beta, and gamma frequency bands, but the exact frequency range and direction of change differed for APP/PS1 mice and human mutation carriers. CONCLUSIONS: Both mice and humans carrying APP and/or PSEN1 mutations show abnormal neurophysiological activity, but several measures do not translate one-to-one between species. Alterations in absolute and relative power in mice should be interpreted with care and may be due to overexpression of amyloid in combination with the absence of tau pathology and cholinergic degeneration. Future studies should explore whether changes in brain activity in other AD mouse models, for instance, those also including tau pathology, provide better translation to the human AD continuum.

Efficiency of maxillomandibular advancement for the treatment of obstructive apnea syndrome: a comprehensive overview of systematic reviews.

OBJECTIVES: To evaluate the efficiency of maxillomandibular advancement using aggregated individual patient data from multiple studies. MATERIALS AND METHODS: This overview was structured according to the PICO strategy. It adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist and was recorded on the international prospective register of systematic reviews (PROSPERO-CRD42020206135). Searches were conducted in the PubMed/MEDLINE, Scopus, Embase, Web of Science, LILACS, and Cochrane databases for studies published until January 1, 2021. Data from the included studies were collected by one author, while another reviewed the compilation. RESULTS: Twelve systematic reviews were included. The outcome measures studied were the apnea-hypopnea index, respiratory disturbance index, mean oxygen saturation, lowest oxygen saturation, sleepiness data, posterior air space, sella-nasion point A angle, sella-nasion point B angle, surgical success, and surgical cure in patients who underwent surgery. The AMSTAR scale presented moderate evaluations, with grades varying between 6 and 10 points. The Glenny scale revealed that the study selection did not include all languages. Only three reviews identified quality assessments conducted by at least two reviewers and only five related possible searches for unpublished data. CONCLUSIONS: Bimaxillary advancement surgery improved respiratory indicators, sleepiness data, and increased upper airway size. However, it is necessary to standardize the surgical criteria to establish measurable efficiency of the procedure. CLINICAL RELEVANCE: This overview makes a critical analysis of the results of the selected systematic reviews with the aim of presenting the most clinically relevant data on the maxillomandibular advancement for treating obstructive apnea syndrome, with a focus on improving respiratory, anatomical, and quality of life indices. There are no overviews that approach this theme from a well-structured perspective.

Masticatory performance of denture wearers with the use of denture adhesives: A systematic review.

STATEMENT OF PROBLEM: Denture adhesives are products used by wearers of removable dental prosthesis; however, systematic reviews on their influence on masticatory performance are lacking. PURPOSE: The purpose of this systematic review was to evaluate the efficiency of denture adhesives in improving the masticatory performance of users of complete dentures (CD). MATERIAL AND METHODS: This systematic review was organized from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist, and the methods were registered on the international prospective register of systematic reviews (PROSPERO-CRD42020187385). The focus question was as follows: "Does the use of denture adhesives improve the masticatory performance of patients with removable dental prostheses?" The databases PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Library were used to extract information. RESULTS: The search yielded 1338 articles, of which 6 met the inclusion criteria and were selected. All included studies were crossover randomized controlled trials including bimaxillary edentulous individuals. Masticatory performance was evaluated by using a comminution and sieve method. CONCLUSIONS: Denture adhesives significantly increased the masticatory performance of CD users.

Do Computerized Delivery Systems Promote Less Pain and Anxiety Compared to Traditional Local Anesthesia in Dental Procedures? A Systematic Review of the Literature.

PURPOSE: The aim of this study is to assess whether the use of computerized devices to deliver local anesthesia results in less pain and anxiety compared to traditional anesthesia in adult dental procedures. METHODS: This review was registered at PROSPERO (CRD 42021265046), based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was structured according to the PICO strategy. The studies were selected based on eligibility criteria, and data were collected by 1 author and reviewed by another. RESULTS: Nine of the 10 studies included were randomized controlled trials. Differences related to pain and anxiety were observed, which favored computerized techniques; however, caution should be exercised when interpreting these results due to differences in assessment methods. The studies used different local anesthetics, including 2% lidocaine, 4% articaine, or 3% mepivacaine with epinephrine diluted 1:80,000 to 1:200,000. A total of 560 patients were evaluated. CONCLUSIONS: Computerized anesthesia devices yielded better results than conventionally delivered anesthesia after qualitative evaluation. Nevertheless, conventional anesthesia is widely used, safe, and effective. Due to the heterogeneity among the included studies, it is strongly recommended that new randomized clinical trials using well-defined methodologies be performed to improve the quality of evidence regarding this topic.

Characterizing neural phase-space trajectories via Principal Louvain Clustering.

BACKGROUND: With the growing size and richness of neuroscience datasets in terms of dimension, volume, and resolution, identifying spatiotemporal patterns in those datasets is increasingly important. Multivariate dimension-reduction methods are particularly adept at addressing these challenges. NEW METHOD: In this paper, we propose a novel method, which we refer to as Principal Louvain Clustering (PLC), to identify clusters in a low-dimensional data subspace, based on time-varying trajectories of spectral dynamics across multisite local field potential (LFP) recordings in awake behaving mice. Data were recorded from prefrontal cortex, hippocampus, and parietal cortex in eleven mice while they explored novel and familiar environments. RESULTS: PLC-identified subspaces and clusters showed high consistency across animals, and were modulated by the animals' ongoing behavior. CONCLUSIONS: PLC adds to an important growing literature on methods for characterizing dynamics in high-dimensional datasets, using a smaller number of parameters. The method is also applicable to other kinds of datasets, such as EEG or MEG.

Structural Degradation in Midcingulate Cortex Is Associated with Pathological Aggression in Mice.

Pathological aggression is a debilitating feature of many neuropsychiatric disorders, and cingulate cortex is one of the brain areas centrally implicated in its control. Here we explore the specific role of midcingulate cortex (MCC) in the development of pathological aggression. To this end, we investigated the structural and functional degeneration of MCC in the BALB/cJ strain, a mouse model for pathological aggression. Compared to control animals from the BALB/cByJ strain, BALB/cJ mice expressed consistently heightened levels of aggression, as assessed by the resident-intruder test. At the same time, immunohistochemistry demonstrated stark structural degradation in the MCC of aggressive BALB/cJ mice: Decreased neuron density and widespread neuron death were accompanied by increased microglia and astroglia concentrations and reactive astrogliosis. cFos staining indicated that this degradation had functional consequences: MCC activity did not differ between BALB/cJ and BALB/cByJ mice at baseline, but unlike BALB/cByJ mice, BALB/cJ mice failed to activate MCC during resident-intruder encounters. This suggests that structural and functional impairments of MCC, triggered by neuronal degeneration, may be one of the drivers of pathological aggression in mice, highlighting MCC as a potential key area for pathologies of aggression in humans.

A central role for anterior cingulate cortex in the control of pathological aggression.

Controlling aggression is a crucial skill in social species like rodents and humans and has been associated with anterior cingulate cortex (ACC). Here, we directly link the failed regulation of aggression in BALB/cJ mice to ACC hypofunction. We first show that ACC in BALB/cJ mice is structurally degraded: neuron density is decreased, with pervasive neuron death and reactive astroglia. Gene-set enrichment analysis suggested that this process is driven by neuronal degeneration, which then triggers toxic astrogliosis. cFos expression across ACC indicated functional consequences: during aggressive encounters, ACC was engaged in control mice, but not BALB/cJ mice. Chemogenetically activating ACC during aggressive encounters drastically suppressed pathological aggression but left species-typical aggression intact. The network effects of our chemogenetic perturbation suggest that this behavioral rescue is mediated by suppression of amygdala and hypothalamus and activation of mediodorsal thalamus. Together, these findings highlight the central role of ACC in curbing pathological aggression.

Large-Scale and Multiscale Networks in the Rodent Brain during Novelty Exploration.

Neural activity is coordinated across multiple spatial and temporal scales, and these patterns of coordination are implicated in both healthy and impaired cognitive operations. However, empirical cross-scale investigations are relatively infrequent, because of limited data availability and to the difficulty of analyzing rich multivariate datasets. Here, we applied frequency-resolved multivariate source-separation analyses to characterize a large-scale dataset comprising spiking and local field potential (LFP) activity recorded simultaneously in three brain regions (prefrontal cortex, parietal cortex, hippocampus) in freely-moving mice. We identified a constellation of multidimensional, inter-regional networks across a range of frequencies (2-200 Hz). These networks were reproducible within animals across different recording sessions, but varied across different animals, suggesting individual variability in network architecture. The theta band (∼4-10 Hz) networks had several prominent features, including roughly equal contribution from all regions and strong inter-network synchronization. Overall, these findings demonstrate a multidimensional landscape of large-scale functional activations of cortical networks operating across multiple spatial, spectral, and temporal scales during open-field exploration.

Beta2 Oscillations in Hippocampal-Cortical Circuits During Novelty Detection.

Novelty detection is a core feature of behavioral adaptation and involves cascades of neuronal responses-from initial evaluation of the stimulus to the encoding of new representations-resulting in the behavioral ability to respond to unexpected inputs. In the past decade, a new important novelty detection feature, beta2 (~20-30 Hz) oscillations, has been described in the hippocampus (HC). However, the interactions between beta2 and the hippocampal network are unknown, as well as the role-or even the presence-of beta2 in other areas involved with novelty detection. In this work, we combined multisite local field potential (LFP) recordings with novelty-related behavioral tasks in mice to describe the oscillatory dynamics associated with novelty detection in the CA1 region of the HC, parietal cortex, and mid-prefrontal cortex. We found that transient beta2 power increases were observed only during interaction with novel contexts and objects, but not with familiar contexts and objects. Also, robust theta-gamma phase-amplitude coupling was observed during the exploration of novel environments. Surprisingly, bursts of beta2 power had strong coupling with the phase of delta-range oscillations. Finally, the parietal and mid-frontal cortices had strong coherence with the HC in both theta and beta2. These results highlight the importance of beta2 oscillations in a larger hippocampal-cortical circuit, suggesting that beta2 plays a role in the mechanism for detecting and modulating behavioral adaptation to novelty.

Comparison of three anesthetic techniques for the removal of posterior mandibular teeth with 2% lidocaine: a systematic review.

OBJECTIVES: The present systematic review aimed to evaluate whether the IANB (conventional inferior alveolar nerve block) technique is superior to the VA (Vazirani-Akinosi) or GG (Gow-Gates) techniques for anesthesia in the removal of posterior mandibular teeth. MATERIALS AND METHODS: This systematic review was structured according to the PICO strategy, adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist, and was recorded on the international prospective register of systematic reviews (PROSPERO-CRD42020153130). Studies were included based on the eligibility criteria and data from the included studies were collected by one author, while another reviewed the compilation. RESULTS: Eight studies were included, all of which were randomized controlled trials. Three studies tested the techniques by exclusively performing lower third molar removal; the others covered other posterior lower teeth. All studies used the same local anesthetic and the same vasoconstrictor: lidocaine 2% with epinephrine/adrenaline. A total of 1056 patients were evaluated. CONCLUSIONS: Some differences were observed between the techniques. Because of the heterogeneity between studies, clinical trials with more specific methodologies, such as comparisons of GG and VA with IANB for mandibular tooth removal, and the same clinical homogeneity will be worthwhile. CLINICAL RELEVANCE: A systematic review of which anesthetic technique is most effective for mandibular teeth removal may positively impact the population's life. There are no systematic reviews which approach this theme in a well-structured perspective.

Low-cost and versatile electrodes for extracellular chronic recordings in rodents.

Electrophysiological data are used to investigate fundamental properties of brain function, its relation to cognition, and its dysfunction in diseases. The development of reliable and open-source systems for electrophysiological data acquisition is decreasing the total cost of constructing and operating an electrophysiology laboratory, and facilitates low-cost methods to extract and analyze the data (Siegle et al., 2017). Here we detail our method of building custom-designed low-cost electrodes. These electrodes can be customized and manufactured by any researcher to address a broad set of research questions, further decreasing the final cost of an implanted animal. Finally, we present data showing such an electrode has a good signal quality to record LFP.

Fasceíte necrotizante cervical: relato de caso / Cervical necrotizing fasciitis: case report

Introdução: A Fasceíte Necrotizante Cervical é uma infecção rara, geralmente com evolução rápida e progressiva da fáscia superficial e do tecido adiposo subcutâneo. Pode se desenvolver a partir de uma infecção odontogênica que se dissemina para os planos faciais e profundos. O presente trabalho tem por objetivo relatar um caso clínico de uma paciente do gênero feminino, 49 anos de idade, atendida na Emergência do Hospital Getúlio Vargas-PE, com quadro clínico sugestivo de Fasceíte Necrotizante Cervical de origem Odontogênica. Relato de caso: O tratamento proposto foi antibioticoterapia parenteral de amplo espectro, desbridamento cirúrgico radical com instalação de dreno de penrose transfixante submandibular direito, múltiplas exodontias para remoção do foco primário da infecção, além de curativos orientado pela equipe de infectologia. Considerações finais: Excepcionalmente, as Fasceítes Necrotizantes Cervicais devem ter diagnóstico e manejo imediato, devido aos altos índices de destruição, rápida progressão e mortalidade. Nos casos de Fasceíte Necrotizante de origem odontogênica, a antibioticoterapia, remoção do(s) focos(s) de infecção, desbridamento cirúrgico e monitoramento intensivo constituem a terapêutica adequada... (AU)

Introduction: Cervical Necrotizing Fasciitis is a rare infection, usually with rapid and progressive evolution of the superficial fascia and subcutaneous adipose tissue. It can develop from an odontogenic infection that spreads to the facial and deep planes. This study aims to report a clinical case of a 49-year-old female patient, seen at the Emergency Department of Hospital Getúlio Vargas-PE, with a clinical condition suggestive of Cervical Necrotizing Fasciitis of Odontogenic origin. Case report: The proposed treatment was broad-spectrum parenteral antibiotic therapy, radical surgical debridement with the installation of a right submandibular transfixing penrose drain, multiple extractions to remove the primary focus of the infection, in addition to curatives guided by the infectology team. Final considerations: Exceptionally, cervical necrotizing fasciitis must have an immediate diagnosis and management, due to the high rates of destruction, rapid progression and mortality. In cases of Necrotizing Fasciitis of odontogenic origin, antibiotic therapy, removal of the foci (s) of infection, surgical debridement and intensive monitoring constitute the appropriate therapy... (AU)

Fibroma ossificantejuvenil em maxila: relato de caso / Juvenile Ossifying Fibromaof the maxilla: case report

Introdução:As lesões fibro-ósseas constituem-se num grupo de lesões caracterizadas por processos de substituição de osso normal por tecido fibroso contendo material mineralizado.O fibroma ossificante juvenil é uma neoplasia fibro-óssea benigna que acomete indivíduos jovens, de comportamento agressivo local e com altas taxas de recidiva. São relatadas duas variantes denominadas de fibroma ossificante juvenil trabecular (FOJT) e o fibromaossificante juvenil psamomatoide (FOJP). Apesar de ambos os padrões demonstrarem características semelhantes, a predileção para idade e os sítios de acometimento sãoespecíficos.O tratamento indicado varia de enucleção e curetagem à ressecção cirúrgica. Este trabalho tem como objetivo relatar um caso de um paciente portador de Fibroma Ossificante Juvenil na maxila. Relato de caso: J.S.B., 18 anos, sexo masculino, procurou o Serviço de Cirurgia e Traumatologia Bucomaxilofacial do Hospital Getúlio Vargas, em Recife/PE, com queixa de "caroço no rosto" com aproximadamente 5 anos de evolução em maxila direita. Paciente foi submetido ao tratamento cirúrgico conservador mediante enucleação, curetagem e osteotomia periférica e está sendo acompanhado há cerca de 10 meses sem apresentar recidiva. Considerações finais: O tratamento mais conservador escolhido foi considerado de sucesso, efetivo, com mínimo de morbidade. Mas, devido à lesão ser considerada agressiva e por possuir alta taxa de recidivas, necessita-se de longo período de acompanhamento... (AU)

Introduction: Fibro-osseous lesions constitute a group of lesions characterized by processes of replacement of normal bone by fibrous tissue containing mineralized material. Juvenile Ossifying Fibroma is a benign fibro-osseous neoplasm that affects young individuals, local aggressive behavior, with high rates of relapse. Two variants named trabecular juvenile ossifying fibroma (TJOF) and psamomatoid juvenile ossifying fibroma (PJOF) are reported. Although both patterns demonstrate similar characteristics, the predilection for age and the sites of involvement are specific. The indicated treatment varies from enucleation and curettage to surgical resection. This article aims to report a case of a patient with juvenile ossifying fibroma in maxilla.Case report:J.S.B., 18 years old, male, sought the Surgery and Traumatology Service of Hospital Getúlio Vargas, Recife / PE, complaining of a "lump in the face" with approximately 5 years of evolution in right maxila. Patient underwent conservative surgical treatmentwas performed through enucleation, curettage and peripheral osteotomy and has been followed for about 10 months without recurrence.Final considerations: The most conservative treatment chosen was considered successful, effective, with minimal morbidity. However, because the injury is considered aggressive and because it has a high rate of recurrence, a long follow-up period is required... (AU)

Exérese de extenso tórus palatino: relato de caso / Excision of extensive palatine torus: case report

Introdução: O tórus palatino se caracteriza por um desenvolvimento ósseo não patológico que ocorre ao longo da linha média do palato duro. Possui etiologia relacionada a fatores genéticos e ambientais, sendo a exostose mais comum em cavidade oral. O tratamento cirúrgico só é necessário em casos específicos quando o tórus interfere nas funções do sistema estomatognático ou na instalação de prótese total no palato. O presente estudo teve como objetivo relatar um caso clínico de tratamento cirúrgico de extenso tórus palatino onde foi empregado um acesso cirúrgico modificado. Relato de caso: Esse trabalho descreve o caso de uma paciente com um tórus palatino de dimensões atípicas com queixas fonéticas e protéticas. Devido ao tamanho da exostose e para permitir uma abordagem mais simplificada, optou-se por um acesso cirúrgico modificado, que em conjunto com a confecção de placa em resina acrílica para instalação no pós-operatório, auxiliou na recuperação e conforto da paciente. Considerações Finais: A técnica cirúrgica utilizada preveniu possíveis desvantagens relacionadas à técnica tradicional, portanto, garantiu um pós-operatório confortável, podendo ser aplicada em tratamentos de tórus palatino quando bem indicada... (AU)

Introduction: Palatine torus is characterized by a non-pathological bone development that occurs along the midline of the hard palate. It`s etiology is related to genetic and environmental factors, being the most common exostoses in the oral cavity. Surgical treatment is only necessary in specific cases when the torus interferes in the functions of the stomatognathic system or in the installation of total prosthesis in the palate. The present study aimed to report a clinical case of surgical treatment of extensive palatine torus where a modified surgical approach was employed. Case report: This article describes the case of a patient with a palatine torus of atypical dimensions with phonetic and prosthetic complaints.Due to the size of the exostoses and to allow a more simplified approach, a modified surgical access was chosen, which together with the confection of acrylic resin plaque for postoperative installationaided in patient recovery and comfort. Final considerations: The surgical technique used prevented possible disadvantages related to the traditional technique, therefore, it guaranteed a comfortable postoperative period... (AU)

Gradient of Parvalbumin- and Somatostatin-Expressing Interneurons Across Cingulate Cortex Is Differentially Linked to Aggression and Sociability in BALB/cJ Mice.

Successfully navigating social interactions requires the precise and balanced integration of social and environmental cues. When such flexible information integration fails, maladaptive behavioral patterns arise, including excessive aggression, empathy deficits, and social withdrawal, as seen in disorders such as conduct disorder and autism spectrum disorder. One of the main hubs for the context-dependent regulation of behavior is cingulate cortex, specifically anterior cingulate cortex (ACC) and midcingulate cortex (MCC). While volumetric abnormalities of ACC and MCC have been demonstrated in patients, little is known about the exact structural changes responsible for the dysregulation of behaviors such as aggression and social withdrawal. Here, we demonstrate that the distribution of parvalbumin (PV) and somatostatin (SOM) interneurons across ACC and MCC differentially predicts aggression and social withdrawal in BALB/cJ mice. BALB/cJ mice were phenotyped for their social behavior (three-chamber task) and aggression (resident-intruder task) compared to control (BALB/cByJ) mice. In line with previous studies, BALB/cJ mice behaved more aggressively than controls. The three-chamber task revealed two sub-groups of highly-sociable versus less-sociable BALB/cJ mice. Highly-sociable BALB/cJ mice were as aggressive as the less-sociable group-in fact, they committed more acts of socially acceptable aggression (threats and harmless bites). PV and SOM immunostaining revealed that a lack of specificity in the distribution of SOM and PV interneurons across cingulate cortex coincided with social withdrawal: both control mice and highly-sociable BALB/cJ mice showed a differential distribution of PV and SOM interneurons across the sub-areas of cingulate cortex, while for less-sociable BALB/cJ mice, the distributions were near-flat. In contrast, both highly-sociable and less-sociable BALB/cJ mice had a decreased concentration of PV interneurons in MCC compared to controls, which was therefore linked to aggressive behavior. Together, these results suggest that the dynamic balance of excitatory and inhibitory activity across ACC and MCC shapes both social and aggressive behavior.

Hippocampal and cortical communication around micro-arousals in slow-wave sleep.

Sleep plays a crucial role in the regulation of body homeostasis and rhythmicity in mammals. Recently, a specific component of the sleep structure has been proposed as part of its homeostatic mechanism, named micro-arousal. Here, we studied the unique progression of the dynamic behavior of cortical and hippocampal local field potentials (LFPs) during slow-wave sleep-related to motor-bursts (micro-arousals) in mice. Our main results comprised: (i) an abrupt drop in hippocampal LFP amplitude preceding micro-arousals which persisted until the end of motor-bursts (we defined as t interval, around 4s) and a similar, but delayed amplitude reduction in cortical (S1/M1) LFP activity occurring at micro-arousal onset; (ii) two abrupt frequency jumps in hippocampal LFP activity: from Theta (6-12 Hz) to Delta (2-4 Hz), also t seconds before the micro-arousal onset, and followed by another frequency jump from Delta to Theta range (5-7 Hz), now occurring at micro-arousal onset; (iii) a pattern of cortico-hippocampal frequency communication precedes micro-arousals: the analysis between hippocampal and cortical LFP fluctuations reveal high coherence during τ interval in a broader frequency band (2-12 Hz), while at a lower frequency band (0.5-2 Hz) the coherence reaches its maximum after the onset of micro-arousals. In conclusion, these novel findings indicate that oscillatory dynamics pattern of cortical and hippocampal LFPs preceding micro-arousals could be part of the regulatory processes in sleep architecture.

OLMα2 Cells Bidirectionally Modulate Learning.

Inhibitory interneurons participate in mnemonic processes. However, defined roles for identified interneuron populations are scarce. A subpopulation of oriens lacunosum-moleculare (OLM) interneurons genetically defined by the expression of the nicotinic receptor α2 subunit has been shown to gate information carried by either the temporoammonic pathway or Schaffer collaterals in vitro. Here we set out to determine whether selective modulation of OLMα2 cells in the intermediate CA1 affects learning and memory in vivo. Our data show that intermediate OLMα2 cells can either enhance (upon their inhibition) or impair (upon their activation) object memory encoding in freely moving mice, thus exerting bidirectional control. Moreover, we find that OLMα2 cell activation inhibits fear-related memories and that OLMα2 cells respond differently to nicotine in the dorsoventral axis. These results suggest that intermediate OLMα2 cells are an important component in the CA1 microcircuit regulating learning and memory processes. VIDEO ABSTRACT.

Intraosseous Mucoepidermoid Carcinoma in the Mandible.

Although it is a rare neoplasm, intraosseous mucoepidermoid carcinoma is the most common and well-recognized intraosseous salivary gland tumor. Usually, it presents as an asymptomatic volume increase and most patients perceive the presence of the lesion within a year or less of evolution. They are more common in middle-aged adults and have a slight female predilection. They are three times more common in the mandible than in the maxilla and are most often found in the area of the molars and mandibular ramus. The most frequently present symptom is cortical bulging, although some lesions may be discovered as an accidental finding on radiographs. The main modality of treatment for patients with this neoplasm is radical surgical resection, offering a greater chance of cure than the more conservative procedures, such as enucleation or curettage, due to the great possibility of recurrence and tumor metastasis. This paper reports a rare case of intraosseous mucoepidermoid carcinoma occasionally discovered after panoramic radiography of the jaws, which was treated with segmental resection through hemimandibulectomy.

Object recognition impairment and rescue by a dopamine D2 antagonist in hyperdopaminergic mice.

Genetically-modified mice without the dopamine transporter (DAT) are hyperdopaminergic, and serve as models for studies of addiction, mania and hyperactive disorders. Here we investigated the capacity for object recognition in mildly hyperdopaminergic mice heterozygous for DAT (DAT +/-), with synaptic dopaminergic levels situated between those shown by DAT -/- homozygous and wild-type (WT) mice. We used a classical dopamine D2 antagonist, haloperidol, to modulate the levels of dopaminergic transmission in a dose-dependent manner, before or after exploring novel objects. In comparison with WT mice, DAT +/- mice showed a deficit in object recognition upon subsequent testing 24h later. This deficit was compensated by a single 0.05mg/kg haloperidol injection 30min before training. In all mice, a 0.3mg/kg haloperidol injected immediately after training impaired object recognition. The results indicate that a mild enhancement of dopaminergic levels can be detrimental to object recognition, and that this deficit can be rescued by a low dose of a D2 dopamine receptor antagonist. This suggests that novel object recognition is optimal at intermediate levels of D2 receptor activity.