Sensory and motor electrophysiological mapping of the cerebellum in humans

Cerebellar damage during posterior fossa surgery in children can lead to ataxia and risk of cerebellar mutism syndrome. Compartmentalisation of sensorimotor and cognitive functions within the cerebellum have been demonstrated in animal electrophysiology and human imaging studies. Electrophysiological monitoring was carried out under general anaesthesia to assess the limb sensorimotor representation within the human cerebellum for assessment of neurophysiological integrity to reduce the incidence of surgical morbidities. Thirteen adult and paediatric patients undergoing posterior fossa surgery were recruited. Sensory evoked field potentials were recorded in response to mapping (n = 8) to electrical stimulation of limb nerves or muscles. For motor mapping (n = 5), electrical stimulation was applied to the surface of the cerebellum and evoked EMG responses were sought in facial and limb muscles. Sensory evoked potentials were found in two patients (25%). Responses were located on the surface of the right inferior posterior cerebellum to stimulation of the right leg in one patient, and on the left inferior posterior lobe in another patient to stimulation of left forearm. No evoked EMG responses were found for the motor mapping. The present study identifies challenges with using neurophysiological methods to map functional organization within the human cerebellum and considers ways to improve success.

Ischnura praematura sp. nov. (Odonata: Zygoptera: Coenagrionidae): a species from Yunnan (China) whose females mate in the teneral state

Ischnura praematura sp. nov. (Holotype ♂, China, Yunnan, Lijiang, 26º31´03.54”N, 100º13’38.89”E, 2396 m, 04 xii 2015, I. Sanmartín-Villar & H. Zhang leg.) is morphologically described, illustrated and compared with close species of the genus. Ischnura praematura can be mainly distinguished from its congeners I. aurora, I. rubilio and I. asiatica by its abdominal and thoracic morphology and colouration. The posterior lobe of the prothorax is elevated in I. praematura and the mesostigmal plates possess dorsal triangular protuberances. Ischnura praematura shows pointed paraprocts, internalised wide cerci and lacks a dorsal tuberculum in the tenth abdominal segment. The blue abdominal colouration is present in the last three segments (incomplete for segment eight and ten in some individuals). No female polychromatism was detected and all females observed possessed different colouration than male (gynochrome). Morphological distinctiveness of the species is supported by genetic analyses, which show that I. praematura forms a well-supported, monophyletic clade, with I. asiatica, I. ezoin and I. pumilio as the most closely related species. In the field, mature females show strong reluctance to mate, and males were observed mating with newly emerged females.

Transcriptomic heterogeneity of Sox2-expressing pituitary cells

The mammalian pituitary gland is a complex organ consisting of hormone-producing cells (HPC), nonhormonal folliculostellate cells (FSC) and pituicytes, vascular pericytes and endothelial cells, and putative Sox2-expressing stem cells. Here, we used scRNAseq analysis of adult female rat pituitary cells to study the heterogeneity of pituitary cells with a focus on evaluating the transcriptomic profile of the Sox2-expressing population. Samples containing whole pituitary and separated anterior and posterior lobe cells allowed the identification of all expected pituitary resident cell types and lobe-specific subpopulations of vascular cells. Sox2 was expressed uniformly in all FSC, pituicytes, and a fraction of HPC. FSC comprised two subclusters; FSC1 contained more cells but expressed less genetic diversity compared to FSC2. The latter contained proliferative cells, expressed genes consistent with stem cell niche formation, including tight junctions, and shared genes with HPC. The FSC2 transcriptome profile was also consistent with the activity of pathways regulating cell proliferation and stem cell pluripotency, including the Hippo and Wnt pathways. The expression of other stem cell marker genes was common for FSC and pituicytes (Sox9, Cd9, Hes1, Vim, S100b) or cell type-specific (FSC: Prop1, Prrx1, Pitx1, Pitx2, Lhx3; pituicytes: Fgf10, Tbx3, Lhx2, Nkx2-1, Rax). FSC and pituicytes also expressed other astroglial marker genes, some common and other distinct, consistent with their identities as astroglial cells of the pituitary. These data suggest functional heterogeneity of FSC, with a larger fraction representing classical FSC, and a smaller fraction containing active stem-like cells and HPC-committed progenitors.

The Genetic Backdrop of Hypogonadotropic Hypogonadism

The pituitary is an organ of dual provenance: the anterior lobe is epithelial in origin, whereas the posterior lobe derives from the neural ectoderm. The pituitary gland is a pivotal element of the axis regulating reproductive function in mammals. It collects signals from the hypothalamus, and by secreting gonadotropins (FSH and LH) it stimulates the ovary into cyclic activity resulting in a menstrual cycle and in ovulation. Pituitary organogenesis is comprised of three main stages controlled by different signaling molecules: first, the initiation of pituitary organogenesis and subsequent formation of Rathke’s pouch; second, the migration of Rathke’s pouch cells and their proliferation; and third, lineage determination and cellular differentiation. Any disruption of this sequence, e.g., gene mutation, can lead to numerous developmental disorders. Gene mutations contributing to disordered pituitary development can themselves be classified: mutations affecting transcriptional determinants of pituitary development, mutations related to gonadotropin deficiency, mutations concerning the beta subunit of FSH and LH, and mutations in the DAX-1 gene as a cause of adrenal hypoplasia and disturbed responsiveness of the pituitary to GnRH. All these mutations lead to disruption in the hypothalamic–pituitary–ovarian axis and contribute to the development of primary amenorrhea.

Laparoscopic S7 hepatectomy for hepatic mucinous neoplasm: a case report and literature review

Background Mucinous cystic neoplasm of the Liver is rare tumors with malignant potential that occur in the biliary epithelium. Because of its rare presentation, it is often misdiagnosed before surgery. Case presentation A 63-year-old female patient presented with intermittent upper abdominal pain for three months. Laparoscopic hepatectomy of Segment 7 was conducted based on the preoperative diagnosis of space-occupying lesion in the right lobe of the liver. Postoperative pathology showed a low-grade mucinous cystic neoplasm in the right posterior lobe of the liver. The preoperative CA19-9 level was significantly increased while the postoperative CA19-9 returned to the normal range. Conclusions The diagnosis of mucinous cystic neoplasm of the liver is closely related to the thickening of the cystic wall or the increase of CA19-9, which has great significance and deserves clinical attention.

A new Idioneura Selys, 1860 for the Brazilian fauna with analysis of the other species (Odonata: Protoneuridae)

Idioneura Selys, 1860 can be separated from the other Protoneuridae (sensu Tillyard 1917) by a set of characters: angulated frons, presence of the CuP&AA vein, absence of the two subapical teeth in the cercus (present in Lamproneura De Marmels, 2003), and first and second antenodal spaces subequal (first a little longer than second). Here is described a new species, Idioneura furieriae spec. nov., from two females and five males. The new species is compared with I. ancilla Selys, 1860 and I. celioi Lencioni, 2009. Diagnostic illustrations are presented. The major differences between Idioneura species are: in the females, the shape of the highly modified mesostigmal plates and posterior lobe of prothorax; in males, the shape of cerci and paraprocts.

Cerebellum

The cerebellum is crucial for planning, executing, terminating, and learning movements. The cerebellum compares actual with intended motor performance and optimizes the timing of motor function. Thus, it is important in the adaptation of movement and posture. In addition, the cerebellum contributes to cognition and behavior. The primary fissure divides the cerebellum anatomically into anterior and posterior lobes. The posterior lobe is divided from the flocculonodular lobe by the posterolateral fissure. The cerebellum may also be divided into functional zones, including the vermis (midline), paravermal region, and hemispheres (most lateral).

Vasopressin and Breathing: Review of Evidence for Respiratory Effects of the Antidiuretic Hormone

Vasopressin (AVP) is a key neurohormone involved in the regulation of body functions. Due to its urine-concentrating effect in the kidneys, it is often referred to as antidiuretic hormone. Besides its antidiuretic renal effects, AVP is a potent neurohormone involved in the regulation of arterial blood pressure, sympathetic activity, baroreflex sensitivity, glucose homeostasis, release of glucocorticoids and catecholamines, stress response, anxiety, memory, and behavior. Vasopressin is synthesized in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus and released into the circulation from the posterior lobe of the pituitary gland together with a C-terminal fragment of pro-vasopressin, known as copeptin. Additionally, vasopressinergic neurons project from the hypothalamus to the brainstem nuclei. Increased release of AVP into the circulation and elevated levels of its surrogate marker copeptin are found in pulmonary diseases, arterial hypertension, heart failure, obstructive sleep apnoea, severe infections, COVID-19 due to SARS-CoV-2 infection, and brain injuries. All these conditions are usually accompanied by respiratory disturbances. The main stimuli that trigger AVP release include hyperosmolality, hypovolemia, hypotension, hypoxia, hypoglycemia, strenuous exercise, and angiotensin II (Ang II) and the same stimuli are known to affect pulmonary ventilation. In this light, we hypothesize that increased AVP release and changes in ventilation are not coincidental, but that the neurohormone contributes to the regulation of the respiratory system by fine-tuning of breathing in order to restore homeostasis. We discuss evidence in support of this presumption. Specifically, vasopressinergic neurons innervate the brainstem nuclei involved in the control of respiration. Moreover, vasopressin V1a receptors (V1aRs) are expressed on neurons in the respiratory centers of the brainstem, in the circumventricular organs (CVOs) that lack a blood-brain barrier, and on the chemosensitive type I cells in the carotid bodies. Finally, peripheral and central administrations of AVP or antagonists of V1aRs increase/decrease phrenic nerve activity and pulmonary ventilation in a site-specific manner. Altogether, the findings discussed in this review strongly argue for the hypothesis that vasopressin affects ventilation both as a blood-borne neurohormone and as a neurotransmitter within the central nervous system.

Rare primary hepatic carcinosarcoma composed of hepatocellular carcinoma, cholangiocarcinoma, and sarcoma: a case report

Primary hepatic carcinosarcoma (HCS) is an extremely rare malignant tumor of the liver that contains carcinomatous and sarcomatous components. The diagnosis, treatment, and prognosis of HCS pose great challenges to clinicians. Herein, we present a case of HCS in a 67-year-old man with unique pathological manifestation. Preoperative magnetic resonance imaging showed a malignant lesion in the right liver and a small sub-focus in the left liver. Radical treatment was performed, including excision of the right posterior lobe of the liver, thrombectomy of the right posterior portal vein, and radiofrequency ablation of lesions in the left liver. The specimens were confirmed to be HCS by pathological examinations, which revealed a combination of poorly differentiated hepatocellular carcinoma, moderately differentiated cholangiocellular carcinoma, and spindle cell sarcoma. Transhepatic arterial chemotherapy and embolization was performed after surgery. Unfortunately, pulmonary metastasis occurred 1.5 months later, which meant a poor prognosis. In this report, we discuss the clinicopathological characteristics of this case and factors that affected surgical outcomes, which may add some ideas for the future diagnosis and treatment of HCS patients.

Combination of structural MRI, functional MRI and brain PET-CT provide more diagnostic and prognostic value in patients of cerebellar ataxia associated with anti-Tr/DNER: a case report

Background Brain magnetic resonance imaging (MRI) rarely reveals structural changes in patients with suspected anti-Tr/DNER encephalitis and thus provides very limited information. Here, we combined structural MRI, functional MRI, and positron emission tomography-computed tomography (PET-CT) findings to characterize this rare disorder in a patient. Case presentation A 43-year-old woman presented with progressive cerebellar ataxia, memory impairment, anxiety, and depression. Anti-Tr antibodies were detected in both her serum (1:10) and cerebrospinal fluid (1:10). A diagnosis of anti-Tr-positive autoimmune cerebellar ataxia was established. The patient’s symptoms were worse, but her brain MRI was normal. Meanwhile, voxel-based morphometry analysis showed bilateral reduced cerebellar volume, especially in the posterior lobe and uvula of the cerebellum and the middle of the left temporal lobe compared with 6 sex- and age-matched healthy subjects (6 females, 43 ± 2 years; p < 0.05). Using seed-based functional connectivity analysis, decreased connectivity between the posterior cingulate cortex/precuneus and left frontal lobe compared to the control group (p < 0.05) was detected. PET-CT revealed bilateral hypometabolism in the cerebellum and relative hypermetabolism in the cerebellar vermis and bilateral frontal lobe, but no malignant changes. Conclusions A combination of structural MRI, functional MRI, and brain PET-CT has higher diagnostic and prognostic value than conventional MRI in patients with suspected anti-Tr/DNER encephalitis.