Introduction: Functioning gonadotroph adenomas, also known as follicle-stimulating hormone (FSH)-secreting pituitary adenomas (FSH-omas), are rare pituitary tumors characterized by the secretion of biologically active FSH. Unlike the more common clinically nonfunctioning gonadotroph adenomas, these tumors produce endocrine manifestations due to excessive FSH secretion. Clinical presentation may result from local mass effects such as headache, visual disturbances due to optic chiasmal compression, or from hormonal activity affecting reproductive function. The endocrine manifestations vary between males and females and can lead to diagnostic challenges. Cases: We report two patients with functioning gonadotroph adenomas presenting with distinct clinical manifestations. The first case involved a 23-year-old female who presented with secondary amenorrhea for 4 years, accompanied by personality changes. Abdominal ultrasound demonstrated bilaterally enlarged multicystic ovaries suggestive of ovarian hyperstimulation, which subsequently regressed postoperatively. Biochemical evaluation revealed inappropriately elevated FSH levels (3.5-fold increase), with suppressed luteinizing hormone (LH) and markedly elevated estradiol levels (11-fold increase). Pituitary magnetic resonance imaging (MRI) identified a large sellar–suprasellar mass with mass effect, consistent with a pituitary macroadenoma. The second case involved a 68-year-old male who presented with progressively worsening vision over 2 years. Hormonal evaluation demonstrated elevated FSH levels (4.5-fold increase), with relatively normal LH and low testosterone levels. Pituitary MRI revealed a sellar mass consistent with a pituitary adenoma. Both patients subsequently underwent pterional craniotomy with tumor debulking. Histopathological examination confirmed gonadotroph adenomas, with positive immunohistochemical staining for FSH. Conclusion Functioning gonadotroph adenomas are rare and may present with diverse clinical features related to gonadal hyperstimulation or mass effects. Early recognition of the characteristic hormonal profile and radiological findings is crucial for diagnosis and appropriate management. These cases highlight the importance of considering functioning gonadotroph adenoma in patients presenting with unexplained gonadal hyperstimulation or atypical reproductive hormonal profiles.
Gonadotrophs ; Adenoma

Introduction: Functioning gonadotroph adenomas (FGPAs) in males are rare and typically present with macroorchidism. In elderly patients, the presentation can be confounding. This case illustrates a unique scenario where a pituitary tumor masked the physiological decline of testosterone, maintaining the patient’s stamina despite Introduction testicular involution. Case: A 65-year-old male was referred for a pituitary macroadenoma (10.7 × 10.6 × 11.4 mm) following progressive headaches. Remarkably, the patient denied symptoms of andropause; his stamina, mood, and libido were wellpreserved. Investigations revealed elevated folliclestimulating hormone (15.42 mIU/mL) and luteinizing hormone (12.1 mIU/mL) with normal testosterone levels. Scrotal ultrasound showed bilateral testicular involution (right: 8.66 mL, left: 7.21 mL), contradicting the expected macroorchidism of FGPA. Although the patient felt his vision was normal, a confrontation test revealed temporal visual field defects, indicating chiasmatic compression. This case presents a striking clinical discordance where tumorinduced gonadotropin hypersecretion provided a supraphysiological drive to the involuting testes, maintaining testosterone levels and masking andropause. The primary indication for transsphenoidal surgery is the Introduction evidence of visual field defects. However, removing the adenoma will abruptly eliminate this “hormonal drive.” Postoperative management will focus on rigorous hormonal monitoring. Testosterone replacement therapy is not immediately indicated; rather, it will be carefully planned only if postoperative evaluations demonstrate a significant hormonal decline accompanied by symptomatic hypogonadism. This tailored approach ensures that the benefits of intervention outweigh the potential risks in an elderly patient. Conclusion In elderly patients, FGPAs can mask age-related hormonal decline. In this case, clinicians must treat the patient, not just the tumor. Anticipating a potential decline in postoperative stamina is as crucial as the surgery itself. Comprehensive hormonal evaluation and a personalized approach to therapy are essential to preserve quality of life after the “masking” effect is removed.
Male ; Andropause ; Gonadotrophs

Introduction: Pituitary macroadenomas may present with mass effects, hypopituitarism, or hormone hypersecretion. Hyperprolactinemia, resulting from a prolactin-secreting tumor or stalk compression, typically suppresses gonadotropins. Thus, elevated follicle-stimulating hormone (FSH) and luteinizing hormone (LH) with low testosterone in this context are unusual. We report a macroprolactinoma with a clinically non-functioning gonadotroph adenoma. Case: A 69-year-old male presented with acute giddiness and headache while in Vietnam. He reported reduced libido but no visual symptoms or galactorrhea. Examination showed no neurological deficits, normal visual fields, and secondary sexual characteristics; bilateral testes volume of 25 mL. Magnetic resonance imaging (MRI) brain revealed a 1.6 × 2.2 × 2.1 cm pituitary macroadenoma compressing the optic chiasm and pituitary stalk. Initial pituitary evaluation demonstrated hyperprolactinemia (prolactin >200 µg/L; normal 2.4–13.1), central hypothyroidism (T4 6.8 pmol/L [7.8–14.4], thyroid-stimulating hormone 2.3 mIU/L [0.38–5.3]), elevated FSH (21.5 IU/L [1.2–19.2]) and LH (191 IU/L [1.24–8.62]), low testosterone (8.88 nmol/L), normal insulin-like growth factor 1 (IGF-1) (68 µg/L [46.5–191.9]), and cortisol 237 nmol/L. Cabergoline was initiated at 0.25 mg twice weekly and titrated to 1 mg twice weekly over 4 months, alongside levothyroxine 25 µg daily. Repeated MRI brain 2 months after cabergoline initiation showed a persistent macroadenoma (1.7 × 2.2 × 2.2 cm) with bilateral cavernous sinus extension. Prolactin decreased to <170 µg/L, central hypothyroidism persisted; levothyroxine was optimized, and hydrocortisone was initiated. At the 5-month follow-up, prolactin further improved to 57 µg/L. Central hypothyroidism and borderline adrenal function persisted, requiring continued replacement therapy. Testosterone remained low-normal (10.2 nmol/L) despite elevated FSH (15.4 IU/L) and LH (92 IU/L). Followup MRI and hormonal reassessment were planned in May 2026. Conclusion Profoundly elevated prolactin level >200 µg/L and response to cabergoline reflect true prolactinoma rather than stalk effect. Persistently low testosterone with discordant high FSH/LH suggests a non-functioning gonadotroph component producing biologically inactive gonadotropins. Definitive diagnosis requires histopathological confirmation, while serial biochemical and radiological follow-up guides management and clarifies tumor subtype.
Gonadotrophs ; Hyperprolactinemia

OBJECTIVES: To investigate the role of a neural pathway from oxytocin (OXT) neurons in the paraventricular hypothalamic nucleus (PVN) to γ-aminobutyric acid (GABA) neurons (GABAergic neurons) in the trigeminal nucleus caudalis (TNC) in regulating pain sensitization in a mouse model of chronic migraine and to explore the underlying mechanisms. METHODS: A chronic migraine mouse model was established by intraperitoneal injection of nitroglycerin (NTG, 1 mg/mL, 10 mg/kg) on days 1, 3, 5, 7, and 9. The study consisted of four parts: PartⅠ: 24 male wild-type C57BL/6J mice were divided into four groups (n=6 in each), receiving single or repeated injection of NTG or saline, respectively. Immunofluorescence was used to detect c-Fos and OXT expression in the PVN. Part Ⅱ: 6 male OXT-Cre transgenic C57BL/6J mice were used for anterograde monosynaptic tracing combined with RNAscope and immunofluorescence to identify neural projections from PVN OXT neurons to TNC GABAergic neurons. Part Ⅲ: 30 male OXT-Cre transgenic C57BL/6J mice were bilaterally injected Cre-dependent chemogenetic activation virus into the PVN. These mice were randomly divided into five groups, with six mice in each group. Mice in the clozapine N-oxide (CNO) group and the control group were intra-peritoneally injected with 0.1 mg/mL of CNO solution (1 mg/kg) and the same volume of isotonic normal saline, respectively. 3 hours after the injection, the brain tissues were harvest and c-Fos immunofluorescence staining was performed to verify the efficiency of chemogenetic activation virus. Mice in the model control group and the CNO activated model group were subjected to chronic migraine modeling, with bilateral TNC injection of isotonic normal saline and CNO, respectively, on day 10. The mice in the negative control group were bilaterally intra-TNC injected with isotonic normal saline. After 30 minutes, the Von-Frey filament and acetone tests were used to assess the mechanical pain threshold and cold pain response time in the periorbital region of the mice in these three groups. Part Ⅳ: 24 male OXT-Cre transgenic C57BL/6J mice were bilaterally injected with the Cre-dependent chemogenetic activation virus into the PVN. These mice were randomly divided into four groups, with six mice in each group. Mice in the model control group, the CNO activated model group and the atosiban group were subjected to chronic migraine modeling. On day 10, mice in the negative control group and the model control group were intraperitoneally injected with isotonic normal saline, while mice in the CNO activated model group and the atosiban group were intraperitoneally injected with CNO. After 15 minutes, mice in the atosiban group were bilaterally intra-TNC injected with atosiban, while mice in other three groups were bilaterally intra-TNC injected with isotonic normal saline containing 1% dimethyl sulfoxide. After 15 minutes, the Von-Frey filament and acetone tests were used to assess the mechanical pain threshold and cold pain response time in the periorbital region of the mice. The GABA content in the bilateral TNC was detected by high-performance liquid chromatography (HPLC). RESULTS: Mice with chronic migraine models exhibited reduced periorbital mechanical pain thresholds and increased periorbital cold pain reaction time, accompanied by an increase in both the number of c-Fos⁺ neurons and the percentage of c-Fos⁺ OXT neurons in the PVN (all P<0.05). The anterograde tracing virus and RNAscope combined with immunofluorescence staining showed that PVN OXT neurons projected to TNC GABAergic neurons. Immuno-fluorescence staining demonstrated that compared with the control group, the percentage of c-Fos⁺ OXT neurons in the PVN of CNO group increased (P<0.05). In bilateral intra-TNC drug administration experiments, compared with the model control group, the periorbital mechanical pain threshold increased, and the periorbital cold pain reaction time decreased in the CNO activated model group (both P<0.05). In intraperitoneal drug administration experiments, compared with the CNO activate model group, the periorbital mechanical pain threshold decreased, and the periorbital cold pain reaction time increased in the atosiban group (both P<0.05). HPLC analysis showed that, compared with the negative control group, the model control group and the atosiban group, GABA level of TNC in the CNO activated model group increased (all P<0.05). CONCLUSIONS PVN OXT neurons exert a descending facilitatory effect on GABAergic neurons in the TNC via OXT release, thereby ameliorating pain sensitization in chronic migraine.
Animals ; Paraventricular Hypothalamic Nucleus/physiopathology* ; Male ; Mice, Inbred C57BL ; Migraine Disorders/physiopathology* ; Mice ; GABAergic Neurons/physiology* ; Oxytocin/physiology* ; Disease Models, Animal ; Neurons/physiology* ; Mice, Transgenic ; Neural Pathways ; Chronic Disease

OBJECTIVES: To assess the regulatory effect of cannabidiol (CBD) on circadian rhythm sleep disorders following general anesthesia and explore its potential mechanism in a rat model of propofol-induced rhythm sleep disorder. METHODS: An electrode was embedded in the skull for cortical EEG recording in 24 male SD rats, which were randomized into control, propofol, CBD treatment, and diazepam treatment groups (n=6). Eight days later, a single dose of propofol (10 mg/kg) was injected via the tail vein with anesthesia maintenance for 3 h in the latter 3 groups, and daily treatment with saline, CBD or diazepam was administered via gavage; the control rats received only saline injection. A wireless system was used for collecting EEG, EMG, and body temperature data within 72 h after propofol injection. After data collection, blood samples and hypothalamic tissue samples were collected for determining serum levels of oxidative stress markers and hypothalamic expressions of the key clock proteins. RESULTS: Compared with the control rats, the rats with CBD treatment showed significantly increased sleep time at night (20:00-6:00), especially during the time period of 4:00-6:00 am. Compared with the rats in propofol group, which had prolonged SWS time and increased sleep episodes during 18:00-24:00 and sleep-wake transitions, the CBD-treated rats exhibited a significant reduction of SWS time and fewer SWS-to-active-awake transitions with increased SWS aspects and sleep-wake transitions at night (24:00-08:00). Diazepam treatment produced similar effect to CBD but with a weaker effect on sleep-wake transitions. Propofol caused significant changes in protein expressions and redox state, which were effectively reversed by CBD treatment. CONCLUSIONS CBD can improve sleep structure and circadian rhythm in rats with propofol-induced sleep disorder possibly by regulating hypothalamic expressions of the key circadian clock proteins, suggesting a new treatment option for perioperative sleep disorders.
Animals ; Rats, Sprague-Dawley ; Male ; Cannabidiol/therapeutic use* ; Rats ; Circadian Rhythm/drug effects* ; Propofol/adverse effects* ; Anesthesia, General/adverse effects* ; Sleep Wake Disorders/chemically induced* ; Hypothalamus/metabolism* ; Electroencephalography

OBJECTIVES: To investigate the regulatory role of astrocytes in the dorsomedial hypothalamus (DMH) during sevoflurane anesthesia emergence. METHODS: Forty-two male C57BL/6 mice were randomized into 6 groups (n=7) for assessing astrocyte activation in the dorsomedial hypothalamus (DMH) under sevoflurane anesthesia. Two groups of mice received microinjection of agfaABC1D promoter-driven AAV2 vector into the DMH for GCaMP6 overexpression, and the changes in astrocyte activity during sevoflurane or air inhalation were recorded using calcium imaging. For assessing optogenetic activation of astrocytes, another two groups of mice received microinjection of an optogenetic virus or a control vector into the DMH with optic fiber implantation, and sevoflurane anesthesia emergence was compared using behavioral experiments. In the remaining two groups, electroencephalogram (EEG) recording during sevoflurane anesthesia emergence was conducted after injection of the hChR2-expressing and control vectors. Anesthesia induction and recovery were assessed by observing the righting reflex. EEG data were recorded under 2.0% sevoflurane to calculate the burst suppression ratio (BSR) and under 1.5% sevoflurane for power spectrum analysis. Immunofluorescence staining was performed to visualize the colocalization of GFAP-positive astrocytes with viral protein signals. RESULTS: Astrocyte activity in the DMH decreased progressively as sevoflurane concentration increased. During 2.0% sevoflurane anesthesia, the mice injected with the ChR2-expressing virus exhibited a significantly shortened wake-up time (P<0.05), and optogenetic activation of the DMH astrocytes led to a marked reduction in BSR (P<0.001). Under 1.5% sevoflurane anesthesia, optogenetic activation resulted in a significant increase in EEG gamma power and a significant decrease in delta power in ChR2 group (P<0.01). CONCLUSIONS Optogenetic activation of DMH astrocytes facilitates sevoflurane anesthesia emergence but does not significantly influence anesthesia induction. These findings offer new insights into the mechanisms underlying anesthesia emergence and may provide a potential target for accelerating postoperative recovery and managing anesthesia-related complications.
Animals ; Astrocytes/physiology* ; Sevoflurane ; Mice, Inbred C57BL ; Mice ; Male ; Electroencephalography ; Anesthetics, Inhalation/pharmacology* ; Hypothalamus/cytology* ; Anesthesia Recovery Period ; Methyl Ethers/pharmacology*

OBJECTIVES: To clarify the role of hippocampal glutamate system in regulating HPA axis in mediating the effect of electroacupuncture (EA) at the heart meridian for improving myocardial injury in rats with acute myocardial ischemia (AMI). METHODS: Male SD rats were randomized into sham-operated group, AMI group, EA group, and L-glutamic acid+EA group (n=9). Rat models of AMI were established by left descending coronary artery ligation, and EA was applied at the "Shenmen-Tongli" segment; the rats in L-glutamic acid+EA group were subjected to microinjection of L-glutamic acid into the bilateral hippocampus prior to AMI modeling and EA treatment. Cardiac functions of the rats were evaluated using echocardiography, and ECG and heart rate variation (HRV) were analyzed using PowerLab and LabChart. Pathological changes in the myocardial tissue was examined using HE staining, and serum levels of myocardial enzymes were detected with ELISA. Myocardial expressions of TH and GAP43 were detected with immunohistochemistry, and colocalization of VGLUT1, VGLUT2 and c-fos were observed using immunofluorescence staining; the expressions of VGLUT1, VGLUT2, NMDAR1 and NMDAR2B were detected using Western blotting. RESULTS: The rat models of AMI showed significantly decreased LVEF and LVFS and increased serum levels of myocardial enzymes in positive correlation with the HPA axis. Numerous TH- and GAP43-positive cells were observed in the hippocampus, where the expressions of NE and E, neurons colabeled with VGLUT1, VGLUT2 and c-fos, and expressions of VGLUT1, VGLUT2, NMDAR1, NMDAR2B and Glu increased significantly. All these changes were significantly improved by interventions with EA as compared with those in AMI and L-Glutamate+EA groups. CONCLUSIONS In rats with AMI, EA at the heart meridian can regulate excessive glutamate release in the hippocampus, thereby inhibiting HPA axis hyperactivity and reducing sympathetic nerve activity to protect the myocardial tissue.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Hippocampus/metabolism* ; Rats ; Glutamic Acid/metabolism* ; Myocardial Ischemia/physiopathology* ; Hypothalamo-Hypophyseal System/physiopathology* ; Pituitary-Adrenal System/physiopathology* ; Receptors, N-Methyl-D-Aspartate/metabolism*

OBJECTIVES: To investigate the therapeutic effect of Ziwuliuzhu acupuncture in a rat model of insomnia and its regulatory effect on the glutamic acid (Glu)/γ-aminobutyric acid (GABA)-glutamine (Gln) metabolic loop. METHODS: Forty male SD rats were randomly assigned to control group, model group, Najia group and Nazi group (n=10). In the latter 3 groups, rat models of insomnia were established by intraperitoneal injections of p-chlorophenylalanine and verified using a sodium pentobarbital-induced sleep test. After modeling, the rats in Najia and Nazi groups received acupuncture for 7 days at specifically chosen sets of acupoints based on the Ziwuliuzhu rationale in traditional Chinese medicine. Pathological changes in the hypothalamic tissue of the rats were examined with HE staining, and the levels of Glu and GABA in the hypothalamus were determined with high-performance liquid chromatography (HPLC)-mass spectrometry (MS)/MS. Immunohistochemistry was used to detect the expressions of GABAA receptors (GABAARs) in the hypothalamus, and the expression levels of glutamate decarboxylase (GAD65/67) and glutamine synthetase (GS) were determined with Western blotting. RESULTS: Compared with the model group, the rats in Najia and Nazi groups exhibited decreased Glu levels and GABAA receptor expression and increased GABA levels with a decreased Glu/GABA ratio in the hypothalamus. Ziwuliuzhu acupuncture significantly increased the protein expressions of GAD65 and GAD67 and lowered the expression of GS in the hypothalamus in the rat models of insomnia. CONCLUSIONS Ziwuliuzhu acupuncture produces sedative and hypnotic effects in rat models of insomnia possibly by regulating Glu and GABA-Gln metabolism to restore the excitatory/inhibitory balance between Glu and GABA.
Animals ; Rats, Sprague-Dawley ; Male ; Rats ; gamma-Aminobutyric Acid/metabolism* ; Sleep Initiation and Maintenance Disorders/therapy* ; Glutamine/metabolism* ; Glutamic Acid/metabolism* ; Acupuncture Therapy ; Hypothalamus/metabolism* ; Receptors, GABA-A/metabolism* ; Acupuncture Points

In the face of constantly changing environments, the central nervous system (CNS) rapidly and accurately calculates the body's needs, regulates feeding behavior, and maintains energy homeostasis. The arcuate nucleus of the hypothalamus (ARC) plays a key role in this process, serving as a critical brain region for detecting nutrition-related hormones and regulating appetite and energy homeostasis. Agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons in the ARC are core elements that interact with other brain regions through a complex appetite-regulating network to comprehensively control energy homeostasis. In this review, we explore the discovery and research progress of AgRP neurons in regulating feeding and energy metabolism. In addition, recent advances in terms of feeding behavior and energy homeostasis, along with the redundant neural mechanisms involved in energy metabolism, are discussed. Finally, the challenges and opportunities in the field of neural regulation of feeding and energy metabolism are briefly discussed.
Energy Metabolism/physiology* ; Animals ; Humans ; Hypothalamus/metabolism* ; Neurons/metabolism* ; Feeding Behavior/physiology* ; Brain Stem/metabolism* ; Agouti-Related Protein/metabolism* ; Homeostasis/physiology* ; Neuropeptide Y/metabolism*

Oxytocin is classically termed a 'prosocial neuropeptide' because of its evolutionarily conserved role in promoting affiliative behaviors. Endogenous oxytocin is mainly synthesized by hypothalamic oxytocin neurons and signals through oxytocin receptors (OxtRs). Recent studies with cell type-specific and circuit-specific interrogation have uncovered that oxytocin signals exert pleiotropic neuromodulatory effects through anatomically widespread axonal projections and ubiquitously distributed OxtRs. Dysfunctions of oxytocin signals are closely relevant to brain disorders/diseases. While intranasal oxytocin administration has been demonstrated to be one potential strategy to alleviate some brain disorders/diseases, such as autism, obesity, and anxiety, conflicting clinical outcomes highlight the imperative for precision-targeted neuromodulation strategies. Dissecting the molecular, cellular, and neural circuitry mechanisms underlying oxytocinergic modulation is a prerequisite to achieving this goal. This review provides an overview of the current understanding of the oxytocin system in terms of anatomical structure, neuronal modulation, and signal pathways, and discusses the modulatory roles of oxytocin in social, feeding, emotional, and sensory-related brain functions and brain diseases.
Oxytocin/metabolism* ; Humans ; Animals ; Hypothalamus/physiology* ; Brain/physiology* ; Brain Diseases/physiopathology* ; Receptors, Oxytocin/metabolism*