Ventral Part Research Articles

Cost-effectiveness analysis of extended endoscopic lumbar foraminotomy (EELF) and transforaminal lumbar interbody fusion (TLIF): a prospective observational study

Lumbar foraminal stenosis can be surgically treated by foraminal decompression or facet joint resection and fusion (transforaminal lumbar interbody fusion, TLIF). While conventional foraminal decompression poses a risk of segmental instability, the endoscopic approach (extended endoscopic lumbar foraminotomy, EELF) resects only the ventral part of the facet joint with a horizontal surgical trajectory. A prospective observational study was performed to analyze the cost-effectiveness of EELF versus TLIF. Patients with dominant unilateral radicular pain from lumbar foraminal stenosis at or above L4-5, without severe central stenosis or instability, were included from January 2021 to February 2023. EELF involved sufficient foraminal widening using a reamer, followed by an endoscopic procedure. The primary outcome was the cost per quality-adjusted life year (QALY) gain at postoperative 12 months. Among 26 patients in each group, the primary analysis included 23 EELF patients (mean age: 72 ± 8 years) and 22 TLIF patients (mean age: 70 ± 8 years). EELF was significantly more cost-effective (EELF: $15,536.0 ± 4,190.0/QALY vs. TLIF: $32,869.4 ± 5,429.3/QALY, p < .001) and demonstrated shorter operating times, less blood loss, and shorter length of stay (p < .05), with no significant difference in clinical outcomes. Thus, EELF could be a cost-effective and less invasive alternative for treating lumbar foraminal stenosis.

Linking the Congruency Effect in Memory to Confirmation Bias in Decision-Making Across the Lifespan – Common Roles of the Medial Prefrontal Cortex

Abstract: Memory and decision-making are two key cognitive processes, influencing each other, and possessing various commonalities and differences. The intricate relationship between the two concepts has gained recent emphasis under a neurocognitive system model. The aim of this review is to connect these two areas of research by focusing on two concepts – the congruency effect in memory research and confirmation bias in decision-making research, and to inspire new research directions. In a selective review of the literature, studies were chosen based on their relevance to these topics following comprehensive literature searches. The review begins with an overview of the two concepts, both of which are notably linked to prior experiences, implicating common roles of the medial prefrontal cortex (mPFC). Given the distinct maturation and ageing patterns of the dorsal and the ventral parts of the mPFC (dmPFC and vmPFC), we further explore related research from a developmental cognitive neuroscience perspective. This perspective offers a valuable tool for understanding the underlying mechanisms and suggests potential directions for future research, including investigating the learning processes associated with the memory congruency effect, employing more complete and inclusive lifespan samples and conducting studies on individual differences. In sum, linking these two concepts may shed new light on understanding how humans process new information based on their prior experiences.

Schemas, reinforcement learning and the medial prefrontal cortex.

Schemas are rich and complex knowledge structures about the typical unfolding of events in a context; for example, a schema of a dinner at a restaurant. In this Perspective, we suggest that reinforcement learning (RL), a computational theory of learning the structure of the world and relevant goal-oriented behaviour, underlies schema learning. We synthesize literature about schemas and RL to offer that three RL principles might govern the learning of schemas: learning via prediction errors, constructing hierarchical knowledge using hierarchical RL, and dimensionality reduction through learning a simplified and abstract representation of the world. We then suggest that the orbitomedial prefrontal cortex is involved in both schemas and RL due to its involvement in dimensionality reduction and in guiding memory reactivation through interactions with posterior brain regions. Last, we hypothesize that the amount of dimensionality reduction might underlie gradients of involvement along the ventral-dorsal and posterior-anterior axes of the orbitomedial prefrontal cortex. More specific and detailed representations might engage the ventral and posterior parts, whereas abstraction might shift representations towards the dorsal and anterior parts of the medial prefrontal cortex.

Sex differences in aggression and its neural substrate in a cichlid fish

Aggression is ubiquitous among social species and can function to maintain social dominance hierarchies. The African cichlid fish Astatotilapia burtoni is an ideal study species for studying aggression due to their dominance hierarchy and robust behavioral repertoire. To further understand the potential sex differences in aggression in this species, we characterized aggression in male and female A. burtoni in a mirror assay. We then quantified neural activation patterns in brain regions of the social behavior network (SBN) to investigate if differences in behavior are reflected in the brain with immunohistochemistry by detecting the phosphorylated ribosome marker phospho-S6 ribosomal protein (pS6), a marker for neural activation. We found that A. burtoni perform both identical and sex-specific aggressive behaviors in response to a mirror assay. Females had greater pS6 immunoreactivity than males in the Vv (ventral part of the ventral telencephalon), a homolog of the lateral septum in mammals. Males but not females had higher pS6 immunoreactivity in the ATn after the aggression assay. The ATn (anterior tuberal nucleus) is a homolog of the ventromedial hypothalamus in mammals, which is strongly implicated in the regulation of aggression in males. Several regions also have higher pS6 immunoreactivity in negative controls than fish exposed to a mirror, implicating a role for inhibitory neural processes in suppressing aggression until a relevant stimulus is present. Male and female A. burtoni display both similar and different behavioral patterns in aggression in response to a mirror assay. There are also sex differences in the corresponding neural activation patterns in the SBN. In mirror males but not females, the ATn clusters with the POA, revealing a functional connectivity of these regions that is triggered in an aggressive context in males. These findings suggest that distinct neural circuitry underlie aggressive behavior in male and female A. burtoni, serving as a foundation for future work investigating the molecular and neural underpinnings of sex differences in behavior in this species to reveal fundamental insights into understanding aggression.

The neural ensembles activated by propofol and isoflurane anesthesia across the whole mouse brain.

General anesthesia has been widely used in surgical procedures. Propofol and isoflurane are the most commonly used injectable and inhaled anesthetics, respectively. The various adverse effects induced by propofol and isoflurane are highly associated with the anesthetic-dependent change of brain activities. In this work, we aim to delineate a brain-wide neuronal activity landscape of injectable versus inhaled anesthetics to understand the neural basis underlying the different physiological effects induced by these two major types of anesthetics. Through detailed scanning of the whole mouse brain subjected to propofol or isoflurane anesthesia, in total, we identified 17 subcortical regions, 3 of which (anterodorsal preoptic nucleus, ADP; lateral habenular, LHb; inferior olivary nucleus, ION) were specifically activated by propofol, and 3 (ventral part of the lateral septum, LSV; the intermediate part of the lateral septum, LSI; the solitary tract nucleus, Sol) were specifically activated by isoflurane, with the remaining 11 were activated by both two anesthetics. Moreover, within the 17 brain regions, ADP, SubCV (subcoeruleus nucleus, ventral part), PCRtA (parvicellular reticular nucleus, alpba part) and ION were newly identified that activated by propofol or isoflurane, respectively. By using Targeted Recombination in Active Populations (TRAP) technique, we further showed that propofol and isoflurane largely activate the same group of neurons in supraoptic nucleus (SON), but activate different groups of neurons in central amygdala (CeA). Our results reveals the neural ensembles activated by injectable and inhaled anesthetics, and provides detailed anatomical references for future studies on general anesthesia.

Arterial thoracic outlet syndrome caused by a cervical rib: a combined thoracoscopic and supraclavicular approach for "en bloc"-resection.

A cervical rib is the cause of about 5% of thoracic outlet syndromes (TOS). We report the case of a patient with arterial TOS due to the presence of a cervical rib, managed by combined thoracoscopic and supraclavicular approach. An 18 years old female patient presented with symptoms of arterial TOS. MRI and computed tomography angiography scans showed a tortuous subclavian artery due to a fused cervical and 1st rib. 3-port thoracoscopy was performed, which allowed to mobilize the ventral part of the 1st rib. Supraclavicular access allowed mobilization as well as central division of the ribs. After removal of the ribs, the subclavian artery presented a normal caliber and aspect. In recent years, there has been a trend towards minimally invasive approach to TOS, either by thoracoscopy or by robotic assisted surgery. The advantages of this approach are the "enbloc"-resection of both ribs and the possibility to evaluate the subclavian artery during the same procedure and perform repair if necessary.

Play activity of the Hooded crow &lt;i&gt;Corvus corone cornix&lt;/i&gt;

Three episodes, all similar to each other, of play behaviour by the Hooded crow were observed in September and October 2016 in Piedmont (NW Italy). The game played by the Hooded crow consisted of carrying a walnut in the air with its beak at a height of about 15-20 meters, letting it fall and catching it before it touched the ground, through a fast, sinuous flight that also included some rotations around the axis of its body. At the moment of the recovery of the walnut, the birds were with the dorsal part facing the ground, and the ventral part facing upwards. [Short communication in Italian]

Crustacean Hyperglycemic Hormone and Gonad Histology of Female Spiny Lobster (Panulirus homarus) Inducted by Laserpuncture

Spiny lobster is one of the potential commodities in Indonesia. On the other hand, there is still a problem to fulfill the export-ready stock of spiny lobster. Production engineering can be utilized as one way to overcome the existing problems. Laserpuncture is a new method of production engineering by utilizing low wavelength helium-neon light that can provide biological stimulation to living things resulting in accelerated development. Laserpuncture induction in crustaceans such as lobsters can be done on the eye stalk and ventral part. This study was conducted using completely randomized design method with 4 treatments and 5 repetitions of each treatment. The treatments given are differences in the duration of laserpuncture induction on female spiny lobster including A (2 seconds induction), B (4 seconds induction), C (6 seconds induction), and control (without induction). This study aims to analyze wheter laserpuncture affects Crustacean Hyperglycemic Hormone. CHH and gonad in female spiny lobster. Data analysis in this study was carried out qualitatively which included Crustacean Hyperglycemic Hormone A &amp; B hormone, gonad histology, and survival rate. The results showed that treatment A (2 seconds induction of laserpuncture) on female spinny lobster had the most significant effect compared to other treatments.

DEVELOPMENT OF THE PERINEUM STRUCTURES IN THE EMBRYONIC AND PREFETAL PERIODS

Traditionally, it is believed that the division of the cloaca into the ventral genitourinary pert and the dorsal - ureteric part occurs at the expense of the urorectal septum during the fourth week of intrauterine development. The separation of the cloaca finally ends during the sixth week of fetal development, with the fusion of the urorectal septum with the cloaca membrane. During the seventh week, both departments become separate entities. However, a significant cohort of authors question the traditional view of the mechanisms of cloacal separation.Purpose to establish and visualize the mechanism of cloaca division; to resolve the controversy regarding the role of the urorectal septum in the separation of the cloaca; to reveal the beginnings of future organ complexes of the male perineum.Material and method. Series of sections of 15 embryo preparations (4-7 weeks of gestational age; 4.5-13.5 mm. PCL) and 15 preparations of pre-fetus (7-9 weeks of gestational age; 14.0-35.0 mm. PCL) were studied by the methods of morphological research: microscopy, morphometry. In order to more accurately visualize and understand the processes of formation of the structures of the male perineum, the method of three-dimensional visualization was used.The results of own research. We found a significant number of mitotic divisions in the dorsal and lateral parts of the mesodermal tissue around the cranial part of the cloaca, but the absence of mitotic divisions was observed in the cells of the mesodermal tissue of the urogenital septum. The urorectal septum becomes visible after the cloacal folds separate the cloaca from the hindgut, distal to the junction between the mesonephric ducts and the cloaca. We established that from the 36th day of intrauterine development, an abdominal cavity is formed, which is located inside the urorectal septum and extends in the caudal direction distally from the point of entry of the mesonephric ducts to the middle of the distance between the entrance of the mesonephric ducts and the caudal top of the urorectal septum. On the 41st day of intrauterine development, parts of the mesonephric ducts, which are located between the cloaca and the ureteric buds, gradually disappear. Thus, both ureters and mesonephric ducts have a common entrance to the genitourinary sinus. Taking into account our observations, it should be noted that the division of the cloaca is a direct consequence of the growth and increase in the volume of the mesenchymal tissue that surrounds the cloaca and, especially in the later stages, its ventral part - the genitourinary sinus. During the 6-9th week of intrauterine development, the genitourinary sinus and urinary bladder are formed along with the demarcation of the mesonephric ducts and ureters.Conclusions. We identified three main structures that indirectly affect the division of the cloaca: after the formation of the urorectal septum, a decrease in the frequency of mitotic divisions of the latter is noted, which indicates its temporary and initial role in the division of the cloaca. Disproportionate growth and increase in the volume of mesenchymal tissue of the ventral part and dorsal part of the cloaca significantly affects the change in its shape and its division. The urorectal septum is not a single, separate structure and extends laterally. Finally, role of the abdominal cavity in the distribution of the cloaca is uncertain.

To Sew or Not to Sew: A Case Report

Introduction-Tongue injuries in children vary from slight lacerations to complete amputations. It could be due to fall, self-mutilation, epilepsy, child abuse, or sport injury. The anterior dorsum is the most common site followed by the mid dorsum and anterior ventral part. These injuries may cause dysfunction of tongue, hemorrhage, and disfigurement. Management of injuries of tongue in young children is challenging. There are no established guidelines for managing tongue lacerations. This is a case report of a three-year-old girl with a laceration on the anterolateral part of the tongue with non-approximating wound edges. The laceration extended from the dorsal to the ventral part. The parents were apprehensive about the surgical management of the injury due to the age of their daughter. Hence, healing of the injury with conservative management without suturing was achieved. Conclusion-The management of traumatic injuries of tongue in children is difficult due to their age and cooperation. The pediatrician has to decide whether to heal the tongue by primary or secondary intention. Our decision to allow the healing by secondary intention was successful. The tongue healed without any complications barring a small scar with satisfactory aesthetic and functional outcome. Both the parents and the child were satisfied with the management of the injury.

Regional response to light illuminance across the human hypothalamus.

Light exerts multiple non-image-forming biological effects on physiology including the stimulation of alertness and cognition. However, the subcortical circuitry underlying the stimulating impact of light is not established in humans. We used 7 Tesla functional magnetic resonance imaging to assess the impact of variations in light illuminance on the regional activity of the hypothalamus while healthy young adults (N=26; 16 women; 24.3±2.9 y) were completing two auditory cognitive tasks. We find that, during both the executive and emotional tasks, higher illuminance triggered an activity increase over the posterior part of the hypothalamus, which includes part of the tuberomamillary nucleus and the posterior part of the lateral hypothalamus. In contrast, increasing illuminance evoked a decrease in activity over the anterior and ventral parts of the hypothalamus, encompassing notably the suprachiasmatic nucleus and another part of the tuberomammillary nucleus. Critically, the performance of the executive task was improved under higher illuminance and was negatively correlated with the activity of the posterior hypothalamus area. These findings reveal the distinct local dynamics of different hypothalamus regions that underlie the impact of light on cognition.

Regional response to light illuminance across the human hypothalamus

Light exerts multiple non-image-forming biological effects on physiology including the stimulation of alertness and cognition. However, the subcortical circuitry underlying the stimulating impact of light is not established in humans. We used 7 Tesla functional magnetic resonance imaging to assess the impact of variations in light illuminance on the regional activity of the hypothalamus while healthy young adults (N=26; 16 women; 24.3±2.9 y) were completing two auditory cognitive tasks. We find that, during both the executive and emotional tasks, higher illuminance triggered an activity increase over the posterior part of the hypothalamus, which includes part of the tuberomamillary nucleus and the posterior part of the lateral hypothalamus. In contrast, increasing illuminance evoked a decrease in activity over the anterior and ventral parts of the hypothalamus, encompassing notably the suprachiasmatic nucleus and another part of the tuberomammillary nucleus. Critically, the performance of the executive task was improved under higher illuminance and was negatively correlated with the activity of the posterior hypothalamus area. These findings reveal the distinct local dynamics of different hypothalamus regions that underlie the impact of light on cognition.

Musical Sophistication and Multilingualism: Effects on Arcuate Fasciculus Characteristics.

The processing of auditory stimuli which are structured in time is thought to involve the arcuate fasciculus, the white matter tract which connects the temporal cortex and the inferior frontal gyrus. Research has indicated effects of both musical and language experience on the structural characteristics of the arcuate fasciculus. Here, we investigated in a sample of n = 84 young adults whether continuous conceptualizations of musical and multilingual experience related to structural characteristics of the arcuate fasciculus, measured using diffusion tensor imaging. Probabilistic tractography was used to identify the dorsal and ventral parts of the white matter tract. Linear regressions indicated that different aspects of musical sophistication related to the arcuate fasciculus' volume (emotional engagement with music), volumetric asymmetry (musical training and music perceptual abilities), and fractional anisotropy (music perceptual abilities). Our conceptualization of multilingual experience, accounting for participants' proficiency in reading, writing, understanding, and speaking different languages, was not related to the structural characteristics of the arcuate fasciculus. We discuss our results in the context of other research on hemispheric specializations and a dual-stream model of auditory processing.

Distinct circuits and molecular targets of the paraventricular hypothalamus decode visceral and somatic pain

Visceral and somatic pain serve as protective mechanisms against external threats. Accumulated evidence has confirmed that the paraventricular hypothalamus (PVH) plays an important role in the perception of visceral and somatic pain, whereas the exact neural pathways and molecules distinguishing them remain unclear. Here, we report distinct neuronal ensembles within the PVH dedicated to processing visceral and somatic pain signals. An essential discovery is the distinct expression of P2X3R and VIPR2 in visceral and somatic pain-activated PVH neuronal ensembles. Furthermore, visceral pain- and somatic pain-responsive PVH neuronal ensembles project to specific downstream regions, the ventral part of the lateral septal nucleus (LSV) and the caudal part of the zona incerta (ZIC), respectively. These findings unveil that the PVH acts as a pain sorting center that distinctly processes visceral and somatic pain, identifying potential molecular targets for specific pain processing and providing a new framework for comprehending how the brain processes nociceptive information.

Anatomy of the Male Reproductive System of Sugar Gliders (Petaurus breviceps).

The present study provides a detailed macroscopic examination (with some microscopic insights) of the genital apparatus of seven adult and intact male sugar gliders, as well as one castrated individual. The scrotum is pendulous and attached to the ventral abdominal wall, situated in the caudal part of the abdomen and cranial to the cloacal opening. The testes are oval shaped with their long axes oriented vertically. The epididymides are attached along the caudomedial border of their respective testes. The head and tail of the epididymides are in close proximity to the poles of the testes but are not directly attached. The deferent ducts are positioned laterally to their ipsilateral ureter as they run near the dorsal surface of the urinary bladder. The ampulla of the deferent duct is absent. The penis is located post-scrotally, lacks insertion into the bony pelvis, and has a bifid distal end. The crura of the penis originate within the ischiocavernosus muscles, and there are two bulbs of the penis. When flaccid, the entire penis is concealed in the perineal region and externalizes through an orifice situated in the ventral part of the cloaca, traversing its floor towards the cloacal opening. The urethral external orifice is positioned at the point where the bifurcation of the free part of the penis begins. The prostate gland resides in the pelvic cavity and consists of two parts: a macroscopically visible body surrounding the urethra and a microscopically identifiable portion embedded within the walls of the duct. Sugar gliders possess two pairs of bulbous bulbourethral glands, located dorsally and laterally to the rectum, but lack vesicular glands.

CD34 distribution in C-fiber low threshold mechanoreceptors in the mouse dorsal root ganglion and spinal cord

CD34 is a well-known cell marker of hematopoietic stem/ progenitor cells, endothelial cells, and fibrocytes. In the peripheral nervous system, a certain type of primary sensory neuron C-fiber low threshold mechanoreceptors (C-LTMRs) are reported to express CD34 mRNA. Here, we investigated the distribution of CD34 protein among putative C-LTMRs (pC-LTMR) using pC-LTMR markers such as VGLUT3 and TH in the dorsal root ganglion (DRG) and spinal cord. CD34 was frequently observed in DRG neurons double-positive for VGLUT3 and TH and single-positive for VGLUT3 in C8 and L4 levels, however, in C4 and L1 levels most of CD34-positive DRG neurons were demonstrated to be double-positive for VGLUT3 and TH. As for the termination, CD34-positive DRG neurons terminated in the ventral part of inner lamina II (lamina IIiv). At C4 and L1 levels of the dorsal horn, CD34 was observed in the entire region of lamina IIiv, however, in C8 and L4 levels of the dorsal horn CD34 was not detected in the medial part of lamina IIiv, which receives neural inputs from DRG neurons that innervate palm or sole skin. These results indicate that CD34 is expressed in pC-LTMRs and suggest that CD34 may play a role in providing C-LTMRs with a specific sensation by maintaining neural circuits.

The Glutamine-Glutamate Cycle Contributes to Behavioral Feminization in Female Rats

Plain Language SummaryThe expression of female sexual behaviors in rodents relies on neuronal signaling within the ventromedial nucleus of the hypothalamus (VMH). Neurons located in the ventral lateral part of the VMH (vlVMH) release glutamate and use it as a mediator to transmit neuronal signals. These neurons are surrounded by astrocytes and may engage in metabolic interactions with them during the perinatal period. Astrocytes produce glutamine (Gln), which are transported into neurons as a precursor for producing glutamate. The vlVMH neurons that release glutamate depend on astrocytic Gln more heavily in female than in male pups. Perinatal disruption of Gln supply to neurons sex-differentially alters glutamate-mediated neuronal signaling and results in morphological changes in vlVMH neurons that resemble those of the opposite sex in adult animals. The present study reveals that perinatal blockade at various points of this metabolic pathway consistently decreased the expression of sex behavior of female rats, while it may only moderately reduce or left unaffected the sex behavior of male rats. Additionally, perinatal inhibition of Gln supply to neurons led to compensatory increases in a neuronal enzyme responsible for glutamate production in the hypothalamus of adult female rats. The results of the study demonstrate that an intact Gln-glutamate metabolic cycle between astrocytes and neurons during the perinatal period is necessary for the development of neuronal networks for proper sex behavior expression in female rats. The findings also suggest that behavioral defeminization could occur in the absence of high levels of E2 exposure in the brain of perinatal female rats.

Association of medullary reticular formation ventral part with spasticity in mice suffering from photothrombotic stroke

Strokes cause spasticity via stretch reflex hyperexcitability in the spinal cord, and spastic paralysis due to involuntary muscle contraction in the hands and fingers can severely restrict skilled hand movements. However, the underlying neurological mechanisms remain unknown. Using a mouse model of spasticity after stroke, we demonstrate changes in neuronal activity with and without electrostimulation of the afferent nerve to induce the stretch reflex, measured using quantitative activation-induced manganese-enhanced magnetic resonance imaging. Neuronal activity increased within the ventral medullary reticular formation (MdV) in the contralesional brainstem during the acute post-stroke phase, and this increase was characterised by activation of circuits involved in spasticity. Interestingly, ascending electrostimulation inhibited the MdV activity on the stimulation side in normal conditions.Moreover, immunohistochemical staining showed that, in the acute phase, the density of GluA1, one of the α-amino-3 hydroxy‑5 methyl -4 isoxazolepropionic acid receptor (AMPAR) subunits, at the synapses of MdV neurons was significantly increased. In addition, the GluA1/GluA2 ratio in these receptors was altered at 2 weeks post-stroke, confirming homeostatic plasticity as the underlying mechanisms of spasticity. These results provide new insights into the relationship between impaired skilled movements and spasticity at the acute post-stroke phase.

POST-NATAL DEVELOPMENT OF PRESCAPULAR LYMPH NODE IN ONE-HUMPED CAMEL (Camelus dromedarius): A MORPHOMTRIC STUDY

The study aimed at forming a base line data on prescapular lymph node of one- humped camel (Camelus dromedarius) at post-natal stage of development and determination of the role of the lymph node in disease resistance of the animal species. A morphometric study was conducted on the prescapular lymph nodes of thirty camels (15 each from male and female) collected from Sokoto metropolitan abattoir over a period of three weeks at different post-natal ages. The approximate age of the camels was estimated using rostral dentition. The morphologic observations revealed that the lymph nodes were relatively large elongated, pinkish, palpable structures situated in the caudal and ventral part of the neck, cranial to the shoulder joint and between the superficial pectoral and the sternocephalic muscles. There is a progressive increase in length, width, weight and volume of the lymph nodes with advancement in age in both sexes. These biometrical variables are relatively higher in male than in female.

A hypothalamic circuit for circadian regulation of corticosterone secretion.

The secretion of cortisol in humans and corticosterone (Cort) in rodents follows a daily rhythm which is important in readying the individual for the daily active cycle and is impaired in chronic depression. This rhythm is orchestrated by the suprachiasmatic nucleus (SCN) which governs the activity of neurons in the paraventricular nucleus of the hypothalamus that produce the corticotropin-releasing hormone (PVHCRH neurons). The dorsomedial nucleus of the hypothalamus (DMH) serves as a crucial intermediary, being innervated by the SCN both directly and via relays in the subparaventricular zone, and projecting axons to the PVH, thereby exerting influence over the cortisol/corticosterone rhythm. However, the role and synaptic mechanisms by which DMH neurons regulate the daily rhythm of Cort secretion has not been explored. We found that either ablating or acutely inhibiting the DMH glutamatergic (DMHVglut2) neurons resulted in a 40-70% reduction in the daily peak of Cort. Deletion of the Vglut2 gene within the DMH produced a similar effect, highlighting the indispensable role of glutamatergic signaling. Chemogenetic stimulation of DMHVglut2 neurons led to an increase of Cort levels, and optogenetic activation of their terminals in the PVH in hypothalamic slices directly activated PVHCRH neurons through glutamate release (the DMHVglut2 → PVHCRH pathway). Similarly, ablating, inhibiting, or disrupting GABA transmission by DMH GABAergic (DMHVgat) neurons diminished the circadian peak of Cort, particularly under constant darkness conditions. Chemogenetic stimulation of DMHVgat neurons increased Cort, although with a lower magnitude compared to DMHVglut2 neuron stimulation, suggesting a role in disinhibiting PVHCRH neurons. Supporting this hypothesis, we found that rostral DMHVgat neurons project directly to GABAergic neurons in the caudal ventral part of the PVH and adjacent peri-PVH area (cvPVH), which directly inhibit PVHCRH neurons, and that activating the DMHVgat terminals in the cvPVH in brain slices reduced GABAergic afferent input onto the PVHCRH neurons. Finally, ablation of cvPVHVgat neurons resulted in increased Cort release at the onset of the active phase, affirming the pivotal role of the DMHVgat → cvPVHVgat → PVHCRH pathway in Cort secretion. In summary, our study delineates two parallel pathways transmitting temporal information to PVHCRH neurons, collectively orchestrating the daily surge in Cort in anticipation of the active phase. These findings are crucial to understand the neural circuits regulating Cort secretion, shedding light on the mechanisms governing this physiological process and the coordinated interplay between SCN, DMH, and PVH.