Comparative features of calretinin, calbindin, and parvalbumin expressing interneurons in mouse and monkey primary visual and frontal cortices.

Fundamental differences in excitatory pyramidal cells across cortical areas and species highlight the implausibility of extrapolation from mouse to primate neurons and cortical networks. Far less is known about comparative regional and species-specific features of neurochemically distinct cortical inhibitory interneurons. Here, we quantified the density, laminar distribution, and somatodendritic morphology of inhibitory interneurons expressing one or more of the calcium-binding proteins (CaBPs) (calretinin [CR], calbindin [CB], and/or parvalbumin [PV]) in mouse (Mus musculus) versus rhesus monkey (Macaca mulatta) in two functionally and cytoarchitectonically distinct regions-the primary visual and frontal cortical areas-using immunofluorescent multilabeling, stereological counting, and 3D reconstructions. There were significantly higher densities of CB+ and PV+ neurons in visual compared to frontal areas in both species. The main species difference was the significantly greater density and proportion of CR+ interneurons and lower extent of CaBP coexpression in monkey compared to mouse cortices. Cluster analyses revealed that the somatodendritic morphology of layer 2-3 inhibitory interneurons is more dependent on CaBP expression than on species and area. Only modest effects of species were observed for CB+ and PV+ interneuron morphologies, while CR+ neurons showed no difference. By contrast to pyramidal cells that show highly distinctive area- and species-specific features, here we found more subtle differences in the distribution and features of interneurons across areas and species. These data yield insight into how nuanced differences in the population organization and properties of neurons may underlie specializations in cortical regions to confer species- and area-specific functional capacities.

Therapeutic strategies for well-differentiated papillary mesothelioma of the peritoneum.

OBJECTIVE: Well-differentiated papillary mesothelioma is an uncommon subtype of mesothelioma with a frequently indolent course, although it occasionally manifests in a more aggressive form. To establish a treatment strategy for this rare disease, we report the clinical characteristics and outcomes of 15 patients with well-differentiated papillary mesothelioma. METHODS: All pathologically diagnosed well-differentiated papillary mesothelioma cases were reviewed between 1998 and 2012. RESULTS: Of the 15 cases, 8 and 7 presented with single and multiple lesions, respectively. All cases with single lesions were asymptomatic, while 4 out of the 7 cases with multiple lesions were symptomatic. After tumor excision, none of the eight single-lesion cases experienced tumor recurrence. Among the other seven cases with multiple lesions, only one patient with disseminated lesions died due to disease burden. Five patients with multiple lesions received cisplatin-based intravenous or intraperitoneal chemotherapy, with a mix of complete (n= 2) and partial (n= 2) responses observed. Of particular note, one patient receiving cisplatin and pemetrexed combination chemotherapy experienced complete tumor resolution without any serious toxicity. CONCLUSIONS: We recommend different treatment strategies based on the disease status. If the tumor is completely resectable, an excisional biopsy seems to be sufficient. If complete resection is unavailable for the asymptomatic patient with a localized tumor extent, close follow-up is an appropriate option. When the tumor is extensive or accompanied by symptoms, chemotherapy should be strongly considered.

Differences in parvalbumin and calbindin chemospecificity in the centers of the turtle ascending auditory pathway revealed by double immunofluorescence labeling.

Using double immunofluorescence labeling, quantitative ratio between parvalbumin- and calbindin-containing neurons, neurons that co-localize both peptides, as well as the intensity of their immunoreactivities were studied in the brainstem, midbrain and forebrain auditory centers of two chelonian species, Testudo horsfieldi and Emys orbicularis. In the spiral ganglion and first-order cochlear nuclei, highly immunoreactive parvalbumin-containing neurons predominated, and almost all neurons in these nuclei also exhibited weak immunoreactivity to calbindin. The number of strongly calbindin-immunoreactive (-ir) cells increased in the second-order brainstem auditory centers (the laminar cochlear nucleus, superior olivary complex, lateral lemniscal nucleus), and co-localization with parvalbumin in some of them was observed. In the midbrain, a complementary distribution of parvalbumin and calbindin immunoreactivity was found: the central (core) region of the torus semicircularis showed strong parvalbumin immunoreactivity, while the laminar (belt) nucleus was strongly calbindin-ir. In the thalamic nucleus reuniens, almost complete topographic overlapping of the parvalbumin-ir and calbindin-ir neurons was shown in its dorsomedial region (core), with the intensity of immunoreactivity to calbindin being much higher than that to parvalbumin. The predominance of calbindin immunoreactivity in neurons of the dorsomedial region of the nucleus reuniens is correlated with the existence of the dense calbindin-ir terminal field in its projection area in the telencephalon. We conclude that the turtle auditory pathway is chemically heterogeneous with respect to calcium-binding proteins, the predominance of parvalbumin in the brainstem and midbrain centers giving way to that of calbindin in the forebrain centers; the portion of neurons co-localizing both peptides nonlinearly decreases from lower to higher order centers.

Fallopian tube malignant mixed müllerian tumor (carcinosarcoma): a case report with immunohistochemical profiling.

We report a case of malignant mixed müllerian tumor (MMMT) (carcinosarcoma) of the right fallopian tube in a 69-year-old woman presenting with abdominal pain and an adnexal mass. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, received adjuvant chemotherapy and is without evidence of disease 12 months postoperatively. The tumor involved the fallopian tube and was composed of in situ and invasive high-grade serous and undifferentiated carcinoma, leiomyosarcoma, rhabdomyosarcoma and undifferentiated sarcoma. Immunohistochemically, the epithelial and mesenchymal cells expressed CD56, Leu-7 and p53. The epithelial elements expressed nuclear WT1 and calretinin while the mesenchymal cells showed negative nuclear and strong cytoplasmic staining. HBME was observed focally in carcinoma. The expression of mesothelial-associated antigens WT1, calretinin and HBME in MMMT likely reflects the common embryologic derivation of the mesothelium and urogenital ridge. Loss of nuclear WT1 expression in the mesenchymal component may be involved in MMMT tumorigenesis.

Morphological aspects as prognostic factors in malignant mesothelioma: a study of 58 cases.

OBJECTIVE: Various markers have shown promise as diagnostic markers and prognostic predictors in malignant mesothelioma (MM). METHODS: Through morphometric and immunological studies of markers in stromal components (calretinin, CEA, Leu-M1 and thrombomodulin) and nuclear components (p53 and Ki-67), we evaluated post-diagnosis survival in 58 patients with MM. RESULTS: The histologic pattern of the MM was typical in 50 cases and atypical in 8. Through immunohistochemistry, we confirmed 40 cases of mesothelioma and 11 cases of adenocarcinoma, although we were unable to classify 7 of the 8 cases presenting atypical histologic patterns. Cox multivariate analysis revealed that the risk factor for death was higher (476.2) among patients of advanced age, presenting the biphasic subtype and testing positive for components expressed at the nuclear level. CONCLUSION: The most useful immunohistochemical markers were was calretinin (for mesothelioma) and CEA (for adenocarcinoma). Immunohistochemical quantification of thrombomodulin facilitated the diagnosis of mesothelioma in patients testing positive for both calretinin and CEA. The most useful prognostic information was that provided by the routine histopathological analysis of the tumor type. It is of note that the combination of a mean age of 55 years and 30.5% immunohistochemical markers in nuclear components created a natural dividing point between patients in which survival was shorter than expected and those in which it was longer than expected. Therefore, histopathological analysis offers a powerful weapon with great potential to inform decisions regarding the use of adjuvant chemotherapy after surgical excision of a mesothelioma.

Intracerebral schwannoma clinically and radiologically mimicking meningioma.

A case of intracerebral schwannoma (ICS) occurring in a 33-year-old woman is presented. The patient's history of headache, numbness, tingling and the recent development of weakness of the right upper extremity with right facial droop began during pregnancy. Magnetic resonance imaging (MRI) showed a 4 x 2 x 2 cm heterogeneous, gadolinium-enhanced mass at the left frontoparietal junction, with peritumoral edema and a dural-based attachment. During her pregnancy, the mass increased in size. The surgically resected specimen consisted of lobulated, somewhat gelatinous soft tissue. Microscopically, the tumor demonstrated classic biphasic Antoni type A and B patterns, admixed with degenerative changes. Immunohistochemically, the neoplastic cells were positive for S-100 protein (diffuse and strong), CD34 (primarily in Antoni B areas), glial fibrillary acidic protein (GFAP; weak and diffuse) and calretinin (mainly in Antoni A areas), while none was positive for CD31, estrogen and progesterone receptors, bcl-2, or epithelial membrane antigen (EMA). Ultrastructurally, basal laminae and Luse bodies were identified. The differential diagnosis includes fibrous meningioma, solitary fibrous tumor, and ICS. Twenty-seven cases of ICS were reviewed in which the histological diagnosis was confirmed immunohistochemically or ultrastructually, and the cases were summarized (including the present case). A combined use of immunostains (S-100 protein, EMA, CD34, and maybe calretinin) is of great help in distinguishing ICS from its histological mimickers.

Quantitative neuropathologic correlates of changes in ratio of N-acetylaspartate to creatine in macaque brain.

PURPOSE: To elucidate the neuropathologic basis of transient changes in the ratio of N-acetylaspartate (NAA) to creatine (Cr) in the primate brain by using a simian immunodeficiency virus (SIV)-infected macaque model of the neurologic manifestation of acquired immune deficiency syndrome. MATERIALS AND METHODS: This study was approved by the Massachusetts General Hospital Subcommittee on Research and Animal Care and the Institutional Animal Care and Use Committee of Harvard University. Rhesus macaques infected with SIV were evaluated during the 1st month of infection. A total of 11 animals were studied, including four control animals, three animals sacrificed 12 days after infection, three animals sacrificed 14 days after infection, and one animal sacrificed 28 days after infection. All animals underwent in vivo proton ((1)H) magnetic resonance (MR) spectroscopy, and postmortem frontal lobe tissue was investigated by using high-spectral-resolution (1)H MR spectroscopy of brain extracts. In addition, quantitative neuropathologic analyses were performed. Stereologic analysis was performed to determine neuronal counts, and immunohistochemical analysis was performed to analyze three neuronal markers: synaptophysin, microtubule-associated protein 2 (MAP2), and calbindin. Analysis of variance (ANOVA) was used to determine substantial changes in neuropathologic and MR spectroscopic markers. Spearman rank correlations were calculated between plasma viral load and neuropathologic and spectroscopic markers. RESULTS: During acute infection with SIV, the macaque brain exhibited significant changes in NAA/Cr (P < .02, ANOVA) and synaptophysin (P < .013, ANOVA). There was no significant change in the concentration of Cr. No significant changes were found in neuronal counts or other immunohistochemical neuronal markers. With the Spearman rank test, a significant direct correlation was detected between synaptophysin and ex vivo NAA/Cr (r(s) = 0.72, P < .013). No correlation between NAA/Cr and neuronal counts, calbindin, or MAP2 was found. CONCLUSION: NAA/Cr is a sensitive marker of neuronal injury, not necessarily neuronal loss, and best correlates with synaptophysin, a marker of synaptodendritic dysfunction.

Localization of M2 muscarinic receptor protein in parvalbumin and calretinin containing cells of the adult rat entorhinal cortex using two complementary methods.

We investigated parvalbumin (PV) and calretinin (CR) containing interneurons in the rat entorhinal cortex. RNA amplification following single cell dissection of immunohistochemically labeled cells from layers II to VI revealed that PV cells, in contrast to CR cells, express the m2 muscarinic receptor (M2AchR) protein. Double immunostaining to confirm the results of RNA amplification indicated that the majority of PV cells contain M2AchR protein, whereas only a small proportion of CR cells do. In contrast, a large number of layer I CR cells, which are mostly Cajal-Retzius cells, were positive for M2AchR. RNA amplification following dissection of these cells also revealed that they contain the M2AchR protein. These findings emphasize that there are significant differences in the expression of different proteins, even among similar neuronal types in the same brain region. This highlights the importance of accurately collecting single cells, and knowledge of anatomical details in molecular biological studies.

Folic acid deficiency during late gestation decreases progenitor cell proliferation and increases apoptosis in fetal mouse brain.

In mice and rats, maternal dietary choline intake during late pregnancy modulates mitosis and apoptosis in progenitor cells of the fetal hippocampus and septum. Because choline and folate are interrelated metabolically, we investigated the effects of maternal dietary folate availability on progenitor cells in fetal mouse telencephalon. Timed-pregnant mice were fed a folate-supplemented (FS), control (FCT) or folate-deficient (FD) AIN-76 diet from d 11-17 of pregnancy. FD decreased the number of progenitor cells undergoing cell replication in the ventricular zones of the developing mouse brain septum (46.6% of FCT), caudate putamen (43.5%), and neocortex (54.4%) as assessed using phosphorylated histone H3 (a specific marker of mitotic phase) and confirmed by bromodeoxyuridine (BrdU) labeling of the S phase. In addition, 106.2% more apoptotic cells were found in FD than in FCT fetal septum. We observed 46.8% more calretinin-positive cells in the medial septal-diagonal band region of FD compared with pups from control dams. FS mice did not differ significantly from FCT mice in any of these measures. These results suggest that progenitor cells in fetal forebrain are sensitive to maternal dietary folate during late gestation.

Definition and connections of the entopallium in the zebra finch (Taeniopygia guttata).

In birds the entopallium (formerly known as the core region of ectostriatum) is the major thalamorecipient zone, within the telencephalon, of the tectofugal visual system. Here we sought to redefine the entopallium in the zebra finch, particularly with respect to a laterally adjacent zone, known as the perientopallium (formerly known as the periectostriatal belt), and to determine its projections. We show that the entopallium can be defined by the almost complete overlap of dense terminations of thalamic rotundal afferents and intense cytochrome oxidase activity and parvalbumin immunoreactivity. The perientopallium, on the other hand, can be defined by relatively sparse projections from nucleus rotundus, a calretinin-positive plexus of nerve fibers, and weak cytochrome oxidase activity and parvalbumin immunoreactivity. Within the entopallium, medial and lateral parts can be distinguished on the basis of cell packing density, differential patterns of parvalbumin immunoreactivity and cytochrome oxidase activity, and different projections. We show that the entopallium projects laterally and diffusely to the perientopallium and nidopallium (formerly the neostriatum) and specifically and densely to a teardrop-shaped nucleus in the ventrolateral mesopallium (formerly known as the hyperstriatum ventrale), here called MVL (abbreviation used as a proper name). This latter projection arises predominantly from medial parts of the entopallium, which also receives a reciprocal projection from MVL, and projects to the lateral striatum. These findings suggest that the entopallium can be divided into medial and lateral parts having different functions, one of which is to provide for an extratelencephalic outflow from the medial part, via the lateral striatum. The findings also challenge the idea that informational flow through the various stations of the telencephalic tectofugal visual system is largely sequential and, together with findings in the chicken (Alpar and Tömböl), suggest instead that further substantial projections to telencephalic visual areas in birds can arise independently from both E (entopallium) and Ep (perientopallial belt).

Green fluorescent protein expression and colocalization with calretinin, parvalbumin, and somatostatin in the GAD67-GFP knock-in mouse.

Gamma-aminobutyric acid (GABA)ergic neurons in the central nervous system regulate the activity of other neurons and play a crucial role in information processing. To assist an advance in the research of GABAergic neurons, here we produced two lines of glutamic acid decarboxylase-green fluorescence protein (GAD67-GFP) knock-in mouse. The distribution pattern of GFP-positive somata was the same as that of the GAD67 in situ hybridization signal in the central nervous system. We encountered neither any apparent ectopic GFP expression in GAD67-negative cells nor any apparent lack of GFP expression in GAD67-positive neurons in the two GAD67-GFP knock-in mouse lines. The timing of GFP expression also paralleled that of GAD67 expression. Hence, we constructed a map of GFP distribution in the knock-in mouse brain. Moreover, we used the knock-in mice to investigate the colocalization of GFP with NeuN, calretinin (CR), parvalbumin (PV), and somatostatin (SS) in the frontal motor cortex. The proportion of GFP-positive cells among NeuN-positive cells (neocortical neurons) was approximately 19.5%. All the CR-, PV-, and SS-positive cells appeared positive for GFP. The CR-, PV, and SS-positive cells emitted GFP fluorescence at various intensities characteristics to them. The proportions of CR-, PV-, and SS-positive cells among GFP-positive cells were 13.9%, 40.1%, and 23.4%, respectively. Thus, the three subtypes of GABAergic neurons accounted for 77.4% of the GFP-positive cells. They accounted for 6.5% in layer I. In accord with unidentified GFP-positive cells, many medium-sized spherical somata emitting intense GFP fluorescence were observed in layer I.

Cyto- and chemoarchitecture of the hypothalamus of a wallaby ( Macropus eugenii) with special emphasis on oxytocin and vasopressinergic neurons.

We have studied the organization of the hypothalamus in an Australian diprotodontid metatherian mammal, the wallaby ( Macropus eugenii), using cytoarchitectural, histochemical and immunohistochemical techniques. Coronal sections of adult brains were processed for Nissl staining, histochemical reactivity (cytochrome oxidase, nicotinamide adenine dinucleotide phosphate diaphorase and acetylcholinesterase) and immunohistochemistry (antibodies to tyrosine hydroxylase, calbindin, calretinin, non-phosphorylated neurofilament protein, oxytocin and vasopressin). The distribution of immunoreactive neurons for these substances was mapped with the aid of a computer-linked microscope. In general, the wallaby hypothalamus showed a similar nuclear organization to that seen in rodents. The paraventricular nucleus could be divided into several subdivisions based on the different cellular parcellation, similar to that described in rodents. The ventromedial hypothalamic nucleus had cell-sparse dorsomedial and cell-dense ventrolateral subdivisions as seen in eutheria, suggesting a similar functional compartmentalization in all theria. The positions of tyrosine hydroxylase-positive neurons in the wallaby hypothalamus were also similar to those in eutheria. Oxytocin and vasopressinergic neurons were found in all the same major nuclear groups as seen in eutheria, although a nucleus circularis could not be identified. The general similarities between wallaby and eutherian hypothalamus indicate that the basic chemo- and cytoarchitectural features of the hypothalamus are common to eutheria and metatheria and validate the use of the wallaby as a mammalian model of wide applicability in investigations of hypothalamic functional development.

Choline availability during embryonic development alters the localization of calretinin in developing and aging mouse hippocampus.

Choline availability in the diet during pregnancy alters fetal brain biochemistry with resulting behavioral changes that persist throughout the lifetime of the offspring. In the present study, the effects of dietary choline on the onset of GABAergic neuronal differentiation in developing fetal brain, as demarcated by the expression of calcium binding protein calretinin, are described. In these studies, timed-pregnant mice were fed choline supplemented, control or choline deficient AIN-76 diet from day 12-17 of pregnancy and the brains of their fetuses were studied on day 17 of gestation. In the primordial dentate gyrus, we found that pups from choline deficient-dams had more calretinin protein (330% increase), and pups from choline supplemented-dams had less calretinin protein (70% decrease), than did pups from control-dams. Importantly, decreased calretinin protein was still detectable in hippocampus in aged, 24-month-old mice, born of choline supplemented-dams and maintained since birth on a control diet. Thus, alterations in the level of calretinin protein in fetal brain hippocampus could underlie the known, life long effects of maternal dietary choline availability on brain development and behavior.

Mouse retina explants after long-term culture in serum free medium.

The neonatal mouse retina remains viable as an explant in serum-supplemented growth media for more than 4 weeks. Interpretation of drug effects on this tissue is compromised by the enigmatic composition of the serum. We sought to remove this ambiguity by culturing neonatal as well as late postnatal mouse retina in serum-free nutrient medium. In this study three important observations were made, (1) there is histotypic development of neonatal as well as preservation of late postnatal mouse retinal structure during long-term culture in serum-free medium, although the late postnatal tissue tends to show some loss of cells in the outer nuclear layer. (2) Protein expression in explant photoreceptor cells was similar to that in the litter-matched ones, except for green cone opsin and interphotoreceptor retinoid-binding protein, although mRNA of the latter is present at similar amounts as in age-matched in vivo controls. (3) Cells of the inner retina stained by antibodies to calcium-binding proteins display some novel sprouting of processes. The results show that the mouse retina can be cultured as an explant for more than 4 weeks in a serum-free medium. This represents an important step forward because, (1) the possibility of interference of drug effects by unknown serum factors has been eliminated; and (2) the spent culture medium can be analyzed to investigate biomolecules released by the retina in vitro.

Organisation and maturation of the human thalamus as revealed by CD15.

The distribution of the CD15 antigen (CD15, 3-fucosyl-N-acetyl-lactosamine, Lewis x) has been studied immunohistochemically in the fetal human thalamus. Its changing patterns could be related to three successive, but overlapping, periods primarily due to its association with radial glial cells, neuropil, and neural cell bodies, respectively. From 9 weeks of gestation (wg), a subset of CD15-positive radial glial cells distinguished the neuroepithelium of the ventral thalamus, a characteristic also seen in the developing mouse. Distal processes of the radial glial cells converged at the root of the forebrain choroid tenia, which was also CD15 positive. From 13 wg until approximately 20 wg, CD15-positive neuropil labeling marked the differentiation areas of prospective nuclei within the dorsal thalamus and progressively outlined their territories in a time sequence, which appeared specific for each nucleus. CD15 labeling of differentiating nuclei of the ventral, medial, anterior, and intralaminar thalamic divisions showed a transient topographic relationship with restricted areas of the ventricular wall. After 26 wg, CD15 immunoreactivity was observed in subpopulations of glial cells and neurons. Transient CD15 immunoreactivity was also found in delimited compartments within the subventricular region. The time of CD15 expression, its location, and cellular association suggest that CD15 is involved in segmentation of diencephalon, in the specification of differentiating nuclear areas and initial processes regarding the formation of intercellular contacts and cellular maturation.

Structural and functional abnormalities of the hippocampal formation in rats with environmentally induced reductions in prepulse inhibition of acoustic startle.

The effects of social isolation on prepulse inhibition of acoustic startle (PPI), electrophysiology and morphology of subicular pyramidal neurons and the densities of interneuronal sub-types in the hippocampal formation were examined. Wistar rats (male weanlings) were housed socially (socials, n=8) or individually (isolates, n=7). When tested eight weeks later, PPI was lower in isolates. Rats then received terminal anaesthesia before slices of hippocampal formation were made in which the electrophysiological properties of a total of 108 subicular neurons were characterized. There were no differences in neuronal sub-types recorded in socials compared with isolates. Intrinsically burst-firing and regular spiking pyramidal neurons were examined in detail. There were no differences in resting membrane potential or input resistance in isolates compared with socials but action potential height was reduced and action potential threshold raised in isolates. A limited morphological examination of Neurobiotin-filled intrinsically burst-firing neurons did not reveal differences in cell-body area or in number of primary dendrites. Sections from the contralateral hemispheres of the same rats were stained with antibodies to calretinin, parvalbumin and the neuronal isoform of nitric oxide synthase (nNOS). In isolates, the density of calretinin positive neurons was increased in the dentate gyrus but unchanged in areas CA3, CA1 and subiculum. Parvalbumin and nNOS positive neuronal densities were unchanged. Hence in rats with environmentally induced reductions in PPI there are structural and functional abnormalities in the hippocampal formation. If the reduction in PPI stems from these abnormalities, and reduced PPI in rats is relevant to schizophrenia, then drugs that correct the reported electrophysiological changes might have antipsychotic effects.

Visual spatial memory is enhanced in female rats (but inhibited in males) by dietary soy phytoestrogens.

BACKGROUND: In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined. RESULTS: Female rats receiving lifelong exposure to a high-phytoestrogen containing diet (Phyto-600) acquired the maze faster than females fed a phytoestrogen-free diet (Phyto-free); in males the opposite diet effect was identified. In a separate experiment, at 80 days-of-age, animals fed the Phyto-600 diet lifelong either remained on the Phyto-600 or were changed to the Phyto-free diet until 120 days-of-age. Following the diet change Phyto-600 females outperformed females switched to the Phyto-free diet, while in males the opposite diet effect was identified.Furthermore, males fed the Phyto-600 diet had significantly higher phytoestrogen concentrations in a number of brain regions (frontal cortex, amygdala & cerebellum); in frontal cortex, expression of CALB (a neuroprotective calcium-binding protein) decreased while COX-2 (an inducible inflammatory factor prevalent in Alzheimer's disease) increased. CONCLUSIONS: Results suggest that dietary phytoestrogens significantly sex-reversed the normal sexually dimorphic expression of VSM. Specifically, in tasks requiring the use of reference, but not working, memory, VSM was enhanced in females fed the Phyto-600 diet, whereas, in males VSM was inhibited by the same diet. These findings suggest that dietary soy derived phytoestrogens can influence learning and memory and alter the expression of proteins involved in neural protection and inflammation in rats.

The distribution of calbindin, calretinin and parvalbumin immunoreactivity in the human thalamus.

UNLABELLED: Calcium-binding proteins show a heterogeneous distribution in the mammalian central nervous system and are useful markers for identifying neuronal populations. The distribution of the three major calcium-binding proteins - calbindin-D28k (calbindin), calretinin and parvalbumin - has been investigated in eight neurologically normal human thalami using standard immunohistochemical techniques. Most thalamic nuclei show immunoreactive cell bodies for at least two of the three calcium-binding proteins; the only nucleus showing immunoreactivity for one calcium-binding protein is the centre médian nucleus (CM) which is parvalbumin-positive. Overall, the calcium-binding proteins show a complementary staining pattern in the human thalamus. In general terms, the highest density of parvalbumin staining is in the component nuclei of the ventral nuclear group (i.e. in the ventral anterior, ventral lateral and ventral posterior nuclear complexes) and in the medial and lateral geniculate nuclear groups. Moderate densities of parvalbumin staining are also present in regions of the mediodorsal nucleus (MD). By contrast, calbindin and calretinin immunoreactivity both show a similar distribution of dense staining in the thalamus which appears to complement the pattern of intense parvalbumin staining. That is, calbindin and calretinin staining is most dense in the rostral intralaminar nuclear group and in the patchy regions of the MD which show very low levels of parvalbumin staining. However, calbindin and calretinin also show low levels of staining in the ventral nuclear complex and in the medial and lateral geniculate bodies which overlaps with the intense parvalbumin staining in these regions. These results show that the calcium-binding proteins are heterogeneously distributed in a complementary fashion within the nuclei of the human thalamus. They provide further support for the concept recently proposed by Jones (Jones, E.G., 1998. VIEWPOINT: the core and matrix of thalamic organization. Neuroscience 85, 331-345) that the primate thalamus comprises of a matrix of calbindin immunoreactive cells and a superimposed core of parvalbumin immunoreactive cells which may have differential patterns of cortical projections.

Characterization of neuronal migration disorders in neocortical structures: loss or preservation of inhibitory interneurons?

PURPOSE: Neuronal migration disorders (NMD) are often associated with therapy-resistant epilepsy. In human cerebral cortex, this hyperexcitability has been correlated with a loss of inhibitory interneurons. We used a rat model of focal cortical NMD (microgyria) to determine whether the expression of epileptiform activity in this model coincides with a decrease in inhibitory interneurons. METHODS: In 2-to 4-month-old rats, the density of interneurons immunoreactive for gamma-aminobutyric acid (GABA), calbindin, and parvalbumin was determined in fronto-parietal cortex in nine 200-microm-wide sectors located up to 2.5 mm lateral and 2.0 mm medial from the lesion center in primary parietal cortex (Par1). Quantitative measurements in homotopic areas of age-matched sham-operated rats served as controls. RESULTS: The freeze lesion performed in newborn rat cortex resulted in adult rats with a microgyrus extending in a rostro-caudal direction from frontal to occipital cortex. The density of GABA-and parvalbumin-positive neurons in fronto-parietal cortex was not significantly different between lesioned and control animals. Only the density of calbindin-immunoreactive neurons located 1.0 mm lateral and 0.5 mm medial from the lesion was significantly (Student t test, p < 0.05) larger in freeze-lesioned rats (5,817 +/- 562 and 6,400 +/- 795 cells per mm3, respectively; n = 12) compared with measurements in homotopic regions in Par1 cortex of controls (4,507 +/- 281 and 4, 061 +/- 319 cells per mm3, respectively; n = 5). CONCLUSIONS: The previously reported widespread functional changes in this model of cortical NMD are not related to a general loss of inhibitory interneurons. Other factors, such as a decrease in GABA receptor density, modifications in GABAA receptor subunit composition, or alterations in the excitatory network, e.g., an increase in the density of calbindin-immunoreactive pyramidal cells, more likely contribute to the global disinhibition and widespread expression of pathophysiological activity in this model of cortical NMD.

The distribution and origin of the calretinin-containing innervation of the nucleus accumbens of the rat.

The nucleus accumbens of the rat consists of several subregions that can be distinguished on the basis of histochemical markers. For example, the calcium-binding protein calbindin D28k is a useful marker of the core compartment of the nucleus accumbens. Calretinin, another calcium-binding protein, is found in a dense fibre plexus in the accumbal shell and septal pole regions. The source of the accumbal calretinin innervation is not known. We examined the distribution of calretinin in the nucleus accumbens and used tract-tracing and lesion methods to determine the source of this calretinin innervation. Intense calretinin immunoreactivity was present in the medial shell, but the density of calretinin axons diminished sharply in the ventrolateral shell. Regions of dense calretinin immunostaining and those areas with calbindin-like immunoreactive cell bodies were generally segregated in the nucleus accumbens, although some overlap in the transition region between the core and shell was seen. Small clusters of calretinin-immunoreactive fibres were seen in the core, where they were restricted to calbindin-negative patches. Injections of the anterograde tracer biotinylated dextran amine into the paraventricular thalamic nucleus labelled fibres in calretinin-rich regions of the accumbens. Conversely, injections of Fluoro-gold into the accumbal shell retrogradely labelled numerous cells in the paraventricular thalamic nucleus that were calretinin-immunoreactive. Electrolytic lesions of the paraventricular thalamic nucleus reduced calretinin levels in the shell by approximately 80%. These data indicate that the calretinin innervation of the nucleus accumbens is derived primarily from the thalamic paraventricular nucleus, and marks accumbal territories that are largely complementary to those defined by calbindin.