The medial prefrontal cortex (mPFC) has been associated with diverse functions including attentional processes, visceromotor activity, decision making, goal directed behavior, and working memory. Using retrograde tracing techniques, we examined, compared, and contrasted afferent projections to the four divisions of the mPFC in the rat: the medial (frontal) agranular (AGm), anterior cingulate (AC), prelimbic (PL), and infralimbic (IL) cortices. Each division of the mPFC receives a unique set of afferent projections. There is a shift dorsoventrally along the mPFC from predominantly sensorimotor input to the dorsal mPFC (AGm and dorsal AC) to primarily 'limbic' input to the ventral mPFC (PL and IL). The AGm and dorsal AC receive afferent projections from widespread areas of the cortex (and associated thalamic nuclei) representing all sensory modalities. This information is presumably integrated at, and utilized by, the dorsal mPFC in goal directed actions. In contrast with the dorsal mPFC, the ventral mPFC receives significantly less cortical input overall and afferents from limbic as opposed to sensorimotor regions of cortex. The main sources of afferent projections to PL/IL are from the orbitomedial prefrontal, agranular insular, perirhinal and entorhinal cortices, the hippocampus, the claustrum, the medial basal forebrain, the basal nuclei of amygdala, the midline thalamus and monoaminergic nuclei of the brainstem. With a few exceptions, there are few projections from the hypothalamus to the dorsal or ventral mPFC. Accordingly, subcortical limbic information mainly reaches the mPFC via the midline thalamus and basal nuclei of amygdala. As discussed herein, based on patterns of afferent (as well as efferent) projections, PL is positioned to serve a direct role in cognitive functions homologous to dorsolateral PFC of primates, whereas IL appears to represent a visceromotor center homologous to the orbitomedial PFC of primates.

Anatomical analysis of afferent projections to the medial prefrontal cortex in the rat

There are seven relaxin family peptides that are all structurally related to insulin. Relaxin has many roles in female and male reproduction, as a neuropeptide in the central nervous system, as a vasodilator and cardiac stimulant in the cardiovascular system, and as an antifibrotic agent. Insulin-like peptide-3 (INSL3) has clearly defined specialist roles in male and female reproduction, relaxin-3 is primarily a neuropeptide involved in stress and metabolic control, and INSL5 is widely distributed particularly in the gastrointestinal tract. Although they are structurally related to insulin, the relaxin family peptides produce their physiological effects by activating a group of four G protein-coupled receptors (GPCRs), relaxin family peptide receptors 1-4 (RXFP1-4). Relaxin and INSL3 are the cognate ligands for RXFP1 and RXFP2, respectively, that are leucine-rich repeat containing GPCRs. RXFP1 activates a wide spectrum of signaling pathways to generate second messengers that include cAMP and nitric oxide, whereas RXFP2 activates a subset of these pathways. Relaxin-3 and INSL5 are the cognate ligands for RXFP3 and RXFP4 that are closely related to small peptide receptors that when activated inhibit cAMP production and activate MAP kinases. Although there are still many unanswered questions regarding the mode of action of relaxin family peptides, it is clear that they have important physiological roles that could be exploited for therapeutic benefit.

https://www.physiology.org/doi/pdf/10.1152/physrev.00001.2012

Relaxin Family Peptides and Their Receptors

Limbic circuitry of the midline thalamus

The nucleus reuniens (RE) is the largest of the midline nuclei of the thalamus and exerts strong excitatory actions on the hippocampus and medial prefrontal cortex. Although RE projections to the hippocampus have been well documented, no study using modern tracers has examined the totality of RE projections. With the anterograde anatomical tracer Phaseolus vulgaris leuccoagglutinin, we examined the efferent projections of RE as well as those of the rhomboid nucleus (RH) located dorsal to RE. Control injections were made in the central medial nucleus (CEM) of the thalamus. We showed that the output of RE is almost entirely directed to the hippocampus and "limbic" cortical structures. Specifically, RE projects strongly to the medial frontal polar, anterior piriform, medial and ventral orbital, anterior cingulate, prelimbic, infralimbic, insular, perirhinal, and entorhinal cortices as well as to CA1, dorsal and ventral subiculum, and parasubiculum of the hippocampus. RH distributes more widely than RE, that is, to several RE targets but also significantly to regions of motor, somatosensory, posterior parietal, retrosplenial, temporal, and occipital cortices; to nucleus accumbens; and to the basolateral nucleus of amygdala. The ventral midline thalamus is positioned to exert significant control over fairly widespread regions of the cortex (limbic, sensory, motor), hippocampus, dorsal and ventral striatum, and basal nuclei of the amygdala, possibly to coordinate limbic and sensorimotor functions. We suggest that RE/RH may represent an important conduit in the exchange of information between subcortical-cortical and cortical-cortical limbic structures potentially involved in the selection of appropriate responses to specific and changing sets of environmental conditions.

Efferent projections of reuniens and rhomboid nuclei of the thalamus in the rat

The mammalian habenula is involved in regulating the activities of serotonergic and dopaminergic neurons. It consists of the medial and lateral habenulae, with each subregion having distinct neural connectivity. Despite the functional significance, manipulating neural activity in a subset of habenular pathways remains difficult because of the poor availability of molecular markers that delineate the subnuclear structures. Thus, we examined the molecular nature of neurons in the habenular subnuclei by analyzing the gene expressions of neurotransmitter markers. The results showed that different subregions of the medial habenula (MHb) use different combinations of neurotransmitter systems and could be categorized as either exclusively glutamatergic (superior part of MHb), both substance P-ergic and glutamatergic (dorsal region of central part of MHb), or both cholinergic and glutamatergic (inferior part, ventral region of central part, and lateral part of MHb). The superior part of the MHb strongly expressed interleukin-18 and was innervated by noradrenergic fibers. In contrast, the inferior part, ventral region of the central part, and lateral part of the MHb were peculiar in that acetylcholine and glutamate were cotransmitted from the axonal terminals. In contrast, neurons in the lateral habenula (LHb) were almost uniformly glutamatergic. Finally, the expressions of Htr2c and Drd2 seemed complementary in the medial LHb division, whereas they coincided in the lateral division, suggesting that the medial and lateral divisions of LHb show strong heterogeneity with respect to monoamine receptor expression. These analyses clarify molecular differences between subnuclei in the mammalian habenula that support their respective functional implications.

Molecular characterization of the subnuclei in rat habenula

The nucleus incertus is located caudal to the dorsal raphe and medial to the dorsal tegmentum. It is composed of a pars compacta and a pars dissipata and contains acetylcholinesterase, glutamic acid decarboxylase, and cholecystokinin-positive somata. In the present study, anterograde tracer injections in the nucleus incertus resulted in terminal-like labeling in the perirhinal cortex and the dorsal endopyriform nucleus, the hippocampus, the medial septum diagonal band complex, lateral and triangular septum medial amygdala, the intralaminar thalamic nuclei, and the lateral habenula. The hypothalamus contained dense plexuses of fibers in the medial forebrain bundle that spread in nearly all nuclei. Labeling in the suprachiasmatic nucleus filled specifically the ventral half. In the midbrain, labeled fibers were observed in the interpeduncular nuclei, ventral tegmental area, periaqueductal gray, superior colliculus, pericentral inferior colliculus, pretectal area, the raphe nuclei, and the nucleus reticularis pontis oralis. Retrograde tracer injections were made in areas reached by anterogradely labeled fibers including the medial prefrontal cortex, hippocampus, amygdala, habenula, nucleus reuniens, superior colliculus, periaqueductal gray, and interpeduncular nuclei. All these injections gave rise to retrograde labeling in the nucleus incertus but not in the dorsal tegmental nucleus. These data led us to conclude that there is a system of ascending projections arising from the nucleus incertus to the median raphe, mammillary complex, hypothalamus, lateral habenula, nucleus reuniens, amygdala, entorhinal cortex, medial septum, and hippocampus. Many of the targets of the nucleus incertus were involved in arousal mechanisms including the synchronization and desynchronization of the theta rhythm.

Cytoarchitecture and efferent projections of the nucleus incertus of the rat.

We are currently living in an era where the use of computer-aided design/computer-aided manufacturing has allowed individualized orthodontic treatments, but has also incorporated enhanced digitalized technology that does not permit improvisation. The purpose of this systematic review was to analyze publications that assessed the accuracy and efficiency of the Invisalign® system. A systematic review was performed using a search strategy to identify articles that referenced Invisalign®, which were published between August 2007 and August 2017, and listed in the following databases: MEDLINE, Embase, Cochrane Library, Web of Knowledge, Google Scholar, and LILACS. Additionally, a manual search of clinical trials was performed in scientific journals and other databases. To rate the methodological quality of the articles, a grading system described by the Swedish Council on Technology Assessment in Health Care was used, in combination with the Cochrane tool for risk of bias assessment. We selected 20 articles that met the inclusion criteria and excluded 5 due to excess biases. The level of evidence was high. Although it is possible to treat malocclusions with plastic systems, the results are not as accurate as those achieved by treatment with fixed appliances.

/pdf/a-systematic-review-of-the-accuracy-and-efficiency-of-dental-30scxnf7wk.pdf

A systematic review of the accuracy and efficiency of dental movements with Invisalign

Background The WHO defines obesity as abnormal excessive fat accumulation. Indeed, it is the most relevant nutritional disorder in the developed countries. Nutrition turns out to be relevant for childhood development involving different systems and organs as and including teeth development. Prediction of teeth eruption results of relevance in odontopediatrics and more particularly at transitional stages with mixed dentition. Early teeth eruption can lead to dental defects and eventually to periodontal disease. In addition to this, obesity increases chronic periodontitis risk on teenagers and young-adults. Objectives: The aim of the work is to confirm the relation of weigh and dental eruption on six years old children. Material and Methods 519 six years old children were included on the analytic observational study. Clinical examination was conducted at school, weight and size was registered for BMI index (Kg/cm2). Permanent teeth presence was recorded during examination. Results Overweight or obesity significantly doubles the probability to find both, the first permanent molars and the lower central incisors. In addition, we report herein a significant association between weight at birth and the first milk tooth eruption. Conclusions Early dental eruption is observed in obese/overweight school children compared to normal weigh children. Key words:Pediatric obesity, tooth eruption, permanent dentition.

Jorge Barcia-Gonzalez

Papers

Cytoarchitecture and efferent projections of the nucleus incertus of the rat.

A systematic review of the accuracy and efficiency of dental movements with Invisalign

Early permanent dental eruption in obese/overweigh schoolchildren