Epilepsy is a common neurological disorder characterized by hyperexcitability in the brain. Its pathogenesis is classically associated with an imbalance of excitatory and inhibitory neurons. Calretinin (CR) is one of the three major types of calcium-binding proteins present in inhibitory GABAergic neurons. The functions of CR and its role in neural excitability are still unknown. Recent data suggest that CR neurons have diverse neurotransmitters, morphologies, distributions, and functions in different brain regions across various species. Notably, CR neurons in the hippocampus, amygdala, neocortex, and thalamus are extremely susceptible to excitotoxicity in the epileptic brain, but the causal relationship is unknown. In this review, we focus on the heterogeneous functions of CR neurons in different brain regions and their relationship with neural excitability and epilepsy. Importantly, we provide perspectives on future investigations of the role of CR neurons in epilepsy.
Amygdala/metabolism* ; Calbindin 2/metabolism* ; Epilepsy ; GABAergic Neurons ; Hippocampus/metabolism* ; Humans

The human nervus terminalis (terminal nerve) and the nerves to the vomeronasal organ (VNON) are both associated with the olfactory nerves and are of major interest to embryologists. However, there is still limited knowledge on their topographical anatomy in the nasal septum and on the number and distribution of ganglion cells along and near the cribriform plate of the ethmoid bone. We observed serial or semiserial sections of 30 fetuses at 7–18 weeks (crown rump length [CRL], 25–160 mm). Calretinin and S100 protein staining demonstrated not only the terminal nerve along the anterior edge of the perpendicular lamina of the ethmoid, but also the VNON along the posterior edge of the lamina. The terminal nerve was composed of 1–2 nerve bundles that passed through the anterior end of the cribriform plate, whereas the VNON consisted of 2–3 bundles behind the olfactory nerves. The terminal nerve ran along and crossed the posterior side of the nasal branch of the anterior ethmoidal nerve. Multiple clusters of small ganglion cells were found on the lateral surfaces of the ethmoid's crista galli, which are likely the origin of both the terminal nerve and VNON. The ganglions along the crista galli were ball-like and 15–20 µm in diameter and, ranged from 40–153 in unilateral number according to our counting at 21-µm-interval except for one specimen (480 neurons; CRL, 137 mm). An effect of nerve degeneration with increasing age seemed to be masked by a remarkable individual difference.
Calbindin 2 ; Ethmoid Bone ; Fetus ; Ganglion Cysts ; Humans ; Individuality ; Masks ; Nasal Septum ; Nerve Degeneration ; Neurons ; Olfactory Nerve ; Vomeronasal Organ

The synaptic contacts of cochlear afferent fibers (CAFs) with inner hair cells (IHCs) are spatially segregated according to their firing properties. CAFs also exhibit spatially segregated vulnerabilities to noise. The CAF fibers contacting the modiolar side of IHCs tend to be more vulnerable. Noise vulnerability is thought to be due to the absence of neuroprotective mechanisms in the modiolar side contacting CAFs. In this study, we investigated whether the expression of neuroprotective Ca²⁺-buffering proteins is spatially segregated in CAFs. The expression patterns of calretinin, parvalbumin, and calbindin were examined in rat CAFs using immunolabeling. Calretinin-rich fibers, which made up ~50% of the neurofilament (NF)-positive fibers, took the pillar side course and contacted all IHC sides. NF-positive and calretinin-poor fibers took the modiolar side pathway and contacted the modiolar side of IHCs. Both fiber categories juxtaposed the C-terminal binding protein 2 (CtBP2) puncta and were contacted by synaptophysin puncta. These results indicated that the calretinin-poor fibers, like the calretinin-rich ones, were afferent fibers and probably formed functional efferent synapses. However, the other Ca²⁺-buffering proteins did not exhibit CAF subgroup specificity. Most CAFs near IHCs were parvalbumin-positive. Only the pillar-side half of parvalbumin-positive fibers coexpressed calretinin. Calbindin was not detected in any nerve fibers near IHCs. Taken together, of the Ca²⁺-buffering proteins examined, only calretinin exhibited spatial segregation at IHC-CAF synapses. The absence of calretinin in modiolar-side CAFs might be related to the noise vulnerability of the fibers.
Animals ; Calbindin 2* ; Calbindins ; Carrier Proteins ; Fires ; Hair Cells, Auditory, Inner ; Intermediate Filaments ; Nerve Fibers ; Noise* ; Rats ; Sensitivity and Specificity ; Synapses ; Synaptophysin

The ganglion cardiacum or juxtaductal body is situated along the left recurrent laryngeal nerve in the aortic window and is an extremely large component of the cardiac nerve plexus. This study was performed to describe the morphologies of the ganglion cardiacum or juxtaductal body in human fetuses and to compare characteristics with intracardiac ganglion. Ganglia were immunostained in specimens from five fetuses of gestational age 12–16 weeks and seven fetuses of gestational age 28–34 weeks. Many ganglion cells in the ganglia were positive for tyrosine hydroxylase (TH; sympathetic nerve marker) and chromogranin A, while a few neurons were positive for neuronal nitric oxide synthase (NOS; parasympathetic nerve marker) or calretinin. Another ganglion at the base of the ascending aorta carried almost the same neuronal populations, whereas a ganglion along the left common cardinal vein contained neurons positive for chromogranin A and NOS but no or few TH-positive neurons, suggesting a site-dependent difference in composite neurons. Mixtures of sympathetic and parasympathetic neurons within a single ganglion are consistent with the morphology of the cranial base and pelvic ganglia. Most of the intracardiac neurons are likely to have a non-adrenergic non-cholinergic phenotype, whereas fewer neurons have a dual cholinergic/noradrenergic phenotype. However, there was no evidence showing that chromogranin A- and/or calretinin-positive cardiac neurons corresponded to these specific phenotypes. The present study suggested that the ganglion cardiacum was composed of a mixture of sympathetic and parasympathetic neurons, which were characterized the site-dependent differences in and near the heart.
Aorta ; Calbindin 2 ; Chromogranin A ; Fetus* ; Ganglia ; Ganglion Cysts* ; Gestational Age ; Heart ; Humans* ; Neurons ; Nitric Oxide Synthase Type I ; Phenotype ; Recurrent Laryngeal Nerve ; Skull Base ; Tyrosine 3-Monooxygenase ; Veins

The circling mice with tmie gene mutation are known as an animal deafness model, which showed hyperactive circling movement. Recently, the reinvestigation of circling mouse was performed to check the inner ear pathology as a main lesion of early hearing loss. In this trial, the inner ear organs were not so damaged to cause the hearing deficit of circling (cir/cir) mouse at 18 postnatal day (P18) though auditory brainstem response data indicated hearing loss of cir/cir mice at P18. Thus, another mechanism may be correlated with the early hearing loss of cir/cir mice at P18. Hearing loss in the early life can disrupt the ascending and descending information to inferior colliculus (IC) as integration site. There were many reports that hearing loss could result in the changes in Ca²⁺ concentration by either cochlear ablation or genetic defect. However, little was known to be reported about the correlation between the pathology of IC and Ca²⁺ changes in circling mice. Therefore, the present study investigated the distribution of calcium-binding proteins (CaBPs), calbindin-D28k, parvalbumin, and calretinin immunoreactivity (IR) in the IC to compare among wild-type (+/+), heterozygous (+/cir), and homozygous (cir/cir) mice by immunohistochemistry. The decreases of CaBPs IR in cir/cir were statistically significant in the neurons as well as neuropil of IC. Thus, this study proposed overall distributional alteration of CaBPs IR in the IC caused by early hearing defect and might be helpful to elucidate the pathology of central auditory disorder related with Ca²⁺ metabolism.
Animals ; Calbindin 1* ; Calbindin 2* ; Calcium-Binding Proteins ; Deafness ; Ear, Inner ; Evoked Potentials, Auditory, Brain Stem ; Hearing ; Hearing Loss ; Immunohistochemistry ; Inferior Colliculi* ; Metabolism ; Mice* ; Neurons ; Neuropil ; Parvalbumins ; Pathology

PURPOSE: To report a case of recurrent myxomatous corneal degeneration after pterygectomy. CASE SUMMARY: A 65-year-old man with a history of abdominal keloid was referred to our hospital for assessment of a well-circumscribed, gelatinous, whitish corneal mass on the nasal corneal area of the left eye that appeared one month prior. The patient had undergone pterygectomy on his left eye 2 years ago. The patient experienced mild foreign body sensation. The other anterior segment and fundus examination of the left eye were both normal. We diagnosed the case as keloid and we performed excisional biopsy of the corneal mass. Histologic findings revealed proliferation of myxoid-appearing material in the anterior corneal stroma. On immunohistochemical examination, sections were stained positive for actin and calretinin, and negative for S-100. We diagnosed the tumor as myxomatous corneal degeneration. After six months, a recurrent mass was found on the previously excised site. Re-excisional biopsy and topical interferon α-2b treatment were then performed in response. After re-excision, there was no recurrence or complications during one year follow-up. CONCLUSIONS: Myxomatous corneal degeneration should be considered during differential diagnosis of an elevated, whitish, gelatinous lesion of the cornea with previous history of trauma or operation, such as pterygectomy. An interferon α-2b topical treatment is useful for recurrent corneal myomatous degeneration.
Actins ; Aged ; Biopsy ; Calbindin 2 ; Cornea ; Corneal Stroma ; Diagnosis, Differential ; Follow-Up Studies ; Foreign Bodies ; Gelatin ; Humans ; Interferons* ; Keloid ; Recurrence ; Sensation

PURPOSE: Hirschsprung’s disease (HD) is a congenital intestinal disorder with absence of ganglion cells in the intestinal muscle and submucosa. Diagnosis is based on histopathological study such as H&E, and acetylcholinesterase (AchE) immunohistochemistry. Calretinin immunohistochemistry was introduced as a new diagnostic method against limitations of other staining. The aim of this study is to investigate the usefulness of calretinin immunohistochemistry for the diagnosis of HD compared to H&E and AchE. METHODS: Ten patients with HD and 22 non-HD patients were included in the study. H&E staining, AchE and calretinin immunohistochemistry were performed in all 32 patients. All slides were evaluated by same single pathologist and the diagnostic value was calculated for each H&E stain, AchE immunohistochemical staining, and calretinin immunohistochemical staining. RESULTS: Calretinin method had sensitivity of 100% and specificity of 100% for diagnosis of HD. Its diagnostic accuracy was 100%. AchE staining showed 100% of specificity and 80% of sensitivity. Diagnostic accuracy of H&E staining was 56.3%. CONCLUSION: We concluded that calretinin immunohistochemistry is a very useful and valuable method to diagnosis HD patient.
Acetylcholinesterase ; Biopsy* ; Calbindin 2* ; Diagnosis ; Ganglion Cysts ; Hematoxylin ; Hirschsprung Disease ; Humans ; Immunohistochemistry* ; Sensitivity and Specificity ; Suction*

Solitary fibrous tumor (SFT) is a derived mesenchymal tumor from spindle cells, mostly occurred in the pleura. To analyze the clinical features of the SFT, data for a patient with SFT that involved in the pleura were retrospectively analyzed by assisted thoracoscope in the Affiliated Hospital of Zunyi Medical College in August 2015. The male patient was 45 years old, who showed the main clinical symptoms of chest pain, cough, sputum, and dyspnea. Large amount of right pleural effusion, chest space-occupying lesions were found by chest CT, suggesting a malignant tumor with metastasis at the 2nd and 3rd right rib. Immunohistochemical results showed: CD34 (+), cytokeratin (-), cytokeratin 5/6 (-), calretinin (-), epithelial membrane antigen(-), mesothelial cell (-), vimentin (++), Wilm's tumor-1 (+), Bcl-2 (+), CD56 (-), CD99 (+), desmin (-), and thyroid transcription factor-1 (-). It was diagnosed as SFT at right side wall layer pleura. SFT is a rare disease and it may occur at any site in the body. It lacks characteristic clinical symptoms and can be asymptomatic, or displays symptoms such as cough, chest pain, dyspnea, and hemoptysis. SFTs can only be conclusively diagnosed based on histopathologic and immunohistochemical characteristics of the tumor, and they are mostly benign. The main treatment for SFTs is the complete surgical resection. The prognosis for this disease is relatively good.
Calbindin 2 ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Prognosis ; Solitary Fibrous Tumor, Pleural ; diagnosis ; surgery ; Thyroid Nuclear Factor 1 ; Tomography, X-Ray Computed

Dopamine plays an important role in cognitive functions including decision making, attention, learning and memory in the anterior cingulate cortex (ACC). However, little is known about dopamine receptors (DAR) expression patterns in ACC neurons, especially GABAergic interneurons. The aim of the present study was to investigate the expression of the most abundant DAR subtypes, D1 receptors (D1Rs) and D2 receptors (D2Rs), in major types of GABAergic interneurons in rat ACC, including parvalbumin (PV)-, calretinin (CR)-, and calbindin D-28k (CB)-containing interneurons. Double immunofluorescence staining and confocal scanning were used to detect protein expression in rat brain sections. The results showed a high proportion of PV-containing interneurons express D1Rs and D2Rs, while a low proportion of CR-positive interneurons express D1Rs and D2Rs. D1R- and D2R-expressing PV interneurons are more prevalently distributed in deep layers than superficial layers of ACC. Moreover, we found the proportion of D2Rs expressed in CR cells is much greater than that of D1Rs. These regional and interneuron type-specific differences of D1Rs and D2Rs indicate functionally distinct roles for dopamine in modulating ACC activities via stimulating D1Rs and D2Rs.
Animals ; Calbindin 1 ; physiology ; Calbindin 2 ; physiology ; Calcium-Binding Proteins ; physiology ; Dopamine ; physiology ; Gyrus Cinguli ; cytology ; Interneurons ; physiology ; Parvalbumins ; physiology ; Rats ; Receptors, Dopamine D1 ; physiology ; Receptors, Dopamine D2 ; physiology

OBJECTIVETo analyze the clinicopathologic and immunohistochemical features of nodular histiocytic/mesothelial hyperplasia (NHMH) and to improve the knowledge of this disease.

METHODSSeven cases of NHMH were collected and the clinicopathologic and immunohistochemical data were analyzed with review of the literature.

RESULTSSeven male patients aged from 1.5 to 5.0 years (mean 2.8). The main clinical symptom was an inguinal mass.Grossly, main pathological changes were the mural nodule or free nodule in lumen, with diameter of 0.1-0.5 cm.Histologically, the tumor cell morphology was relatively single, cohesive polygonal or oval cells which were arranged in solid sheets or nests, usually with ovoid or deeply grooved nuclei and a moderate amount of pale pink cytoplasm in the nodular collection area. The nuclei had delicate chromatin and no obvious atypia, and mitosis was incidentally found. A few scattered lymphocytes were found in the stroma. The cyst wall was lined by a single layer of mesothelial cells.Immunohistochemically, the most cells in nodular lesion were strongly positive for the histiocytic marker CD68, vimentin and α1-antichymotrypsin, while lining mesothelial cells on the wall were positive for calretinin, MC, WT1, CK5/6, CKpan and EMA.

CONCLUSIONSNHMH is a rare and benign tumor-like lesion, and easy to be misdiagnozed, which should be distinguished from neuroendocrine tumors, Langerhans cell histiocytosis, seminoma, mesothelioma and so on. The correct diagnosis of this lesion depends on the clinical characteristics, morphology and immunohistochemistry.

Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Calbindin 2 ; metabolism ; Child, Preschool ; Diagnosis, Differential ; Epithelium ; metabolism ; pathology ; surgery ; Histiocytes ; metabolism ; pathology ; Histiocytosis, Langerhans-Cell ; metabolism ; pathology ; Humans ; Hyperplasia ; metabolism ; pathology ; surgery ; Infant ; Leukocyte Common Antigens ; metabolism ; Male ; Mesothelioma ; metabolism ; pathology ; Mucin-1 ; metabolism ; Neuroendocrine Tumors ; metabolism ; pathology ; Seminoma ; metabolism ; pathology ; Vimentin ; metabolism ; WT1 Proteins ; metabolism ; alpha 1-Antichymotrypsin ; metabolism