NPY-, SOM- and VIP-containing interneurons in postnatal development of the rat claustrum

A growing body of evidence indicates the common origin of the claustrum, endopiriform nucleus, and the basolateral nuclear complex of amygdala from the lateral and ventral parts of the pallium, as the claustroamygdaloid complex. It seems very probable that at least some of the claustral interneurons derive from subcortical sources.The postnatal development of neuropeptide Y-, somatostatin- and vasoactive intestinal polypeptide-containing interneurons was studied during the 4 postnatal months (P0–P120; P, postnatal day). The study was conducted on 45 Wistar rats of both sexes.Our results indicate that neuropeptide-containing interneurons are not morphologically mature at the moment of birth. The characteristic features of neuronal bodies and the relatively long period of postnatal development may indicate their migration from the subcortical neurogenetic centers. Morphological changes in the neuropil are also reported.Although developmental patterns differ between various neuropeptide-containing neuronal subpopulations, two phases of development can be distinguished in each of them: the early phase (P0–P4) during which undifferentiated neurons and neuropil dominate, and the late phase (P7–P28) during which the characteristic features of an adult-like structure gradually appear. Later these observed developmental changes are terminated.The postnatal development of neuropeptide-containing interneurons is completed after 4 weeks of life. This period, which is important for the structural and functional development of the claustrum, must be taken into account in future studies on this structure.     

精神分裂症患者海马区γ-氨基丁酸能中间神经元钙结合蛋白的免疫组化研究

目的：通过定量分析精神分裂症患者海马区γ－氨基丁酸（GABA）能中间神经元相对密度的改变，探讨其在精神分裂症发病机理中的作用。方法：共30例患者的脑组织标本，其中精神分裂症患者15例（精神分裂症组），无神经或精神疾病史者15例（对照组），采用免疫组化法结合抗parvalbumin(PV）和抗calretinin(CR)抗体，测定精神分裂症组和对照组钙结合蛋白（CBPs)免疫反应（IR）阳性细胞在海马本体齿状回和阿蒙角（Ammon‘s horn,CA1-CA4)的分布，胞体大小，相对密度及海马亚区面积。结果：与对照组比较，精神分裂症组CR－IR中间神经元相对密度的差异无显著性（P＞0．05），而PV－IR中间神经元相对密度在海马各亚区均严重缺失，差异有显著性（P＜0．05－0．001），其中以男性患者为著，与年龄，病程和抗精神病药无显著性相关（P＞0．05），结论：精神分裂症患者海马区含PV的GABA能抑制性中间神经元亚群缺失，似符合早期神经发育异常的病因学假说。     

Alterations of interneurons in the striatum and frontal cortex of mice during postnatal development

We investigated the postnatal alterations of neuronal nuclei (NeuN)-positive neurons, parvalbumin (PV)-positive interneurons, neuronal nitric oxide synthase (nNOS)-positive interneurons, and neurotrophic factors in the mouse striatum and frontal cortex using immunohistochemistry. NeuN, PV, nNOS, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) immunoreactivity were measured in 1-, 2-, 4- and 8-week-old mice. Total number of NeuN-positive neurons was unchanged in the mouse striatum and frontal cortex from 1 up to 8 weeks of age. In contrast, a significant decrease in the number of PV-positive interneurons was observed in the striatum and frontal cortex of 1-, 2- and 4-week-old mice. Furthermore, a significant increase of nNOS-positive interneurons was found in the striatum and frontal cortex of 1- and/or 2-week-old mice. NGF-positive neurons were unchanged in the mouse striatum from 1 up to 8 weeks of age. In the frontal cortex, a significant increase in the number of NGF-positive neurons was observed only in 1-week-old mice. In contrast, a significant increase in the number of NGF-positive glia 1 cells was found in the striatum and frontal cortex of 4-week-old mice. Our double-labeled immunostaining showed that nNOS immunoreactivity was not found in PV-immunopositive interneurons. Furthermore, BDNF immunoreactivity was observed in both nNOS-positive and PV-positive interneurons in the striatum of 1- or 2-week-old mice. These results show that the maturation of nNOS-immunopositive interneurons precedes the maturation of PV-immunopositive interneurons in the striatum and frontal cortex during postnatal development. Furthermore, our results demonstrate that the expression of BDNF may play some role in the maturation of interneurons in the striatum and frontal cortex during postnatal development. Moreover, our findings suggest that the expression of NGF in glia cells may play some role in the maturation of glial cells and PV-positive interneurons in the striatum and frontal cortex during postnatal development.     

The postnatal development of glial fibrillary acidic protein and neurofilament triplet proteins in rat brain stem

Cytoskeletal preparations containing both the glial fibrillary acidic protein and the neurofilament triplet proteins were prepared from brain stems of rats at different ages and the individual peptides separated in polyacrylamide gels. Stained peptide bands were quantitated as the area under peaks generated by densitometric scanning. Peak areas were converted to grams of protein based on total gel dye binding and total protein applied to the gels. Between 5 and 30 days, the concentration of the peptide (g of peptide/mg of tissue protein) of apparent molecular weight 51,000 (corresponding to the glial fibrillary acidic protein), increased 3 fold. The corresponding increase in total concentration of the three peptides corresponding to the neurofilament proteins was 4.5 fold. However, the increase in concentration of the individual neurofilament peptides was each different. Very little of the apparent molecular weight 210,000 neurofilament peptide was present at 5 days and its concentration increased 11 fold by 30 days compared to about 3.5 fold for the other two neurofilament peptides. These results are in general agreement with studies using immunological techniques and the methods have the advantages of using readily available techniques and allowing the simultaneous comparison of both neuronal and glial specific filaments during development.     

Differential distribution of six calcium-binding proteins in the rat olfactory epithelium during postnatal development and adulthood

Odorant stimulation of receptor cells results in a calcium influx that activates the transduction pathway. Ca²⁺ acceptors, such as calmodulin, may mediate between the change in intracellular calcium and the conductance mechanism underlying the initial electrical event. Ca²⁺ acceptors also may participate in subsequent processing of olfactory information. The identification and characterization of these molecules, therefore, should provide important information about the complex signal transduction pathway involving calcium in olfaction as well as other sensory systems. The present study describes the distribution of six calcium-binding proteins in the rat main olfactory epithelium during postnatal development to determine when different Ca²⁺ acceptors can be detected and whether they segregate into different layers or p6 rtions of the epithelium. Calmodulin, calretinin, calbindin-D28k, neurocalcin, and recoverin were detected immunohistochemically in olfactory receptors but not in basal cells. S-100 immunoreactivity was restricted to glial cells primarily around the cribriform plate. During postnatal development (from P1 to P20), calmodulin, calretinin, calbindin-D28k, and neurocalcin formed a gradient of immunoreactivity descending from the central to the lateral areas in the nasal cavity, whereas recoverin was expressed only in sporadic, mature receptors in the proximal region of the mucosa. At P20, the immunoreactivity pattern for each calcium-binding protein was identical to the adult profile, indicating that the olfactory epithelium had reached maturity by this stage. Olfactory nerve fiber bundles displayed a differential staining pattern from P 1 until adulthood for calbindin-D28k and calretinin (internal portions of bundles). Differential calmodulin immunoreactivity of olfactory nerves (large external portions of bundles) appeared at P10. The immunoreactivity of the nerve fiber bundles may reflect a further degree of organization relevant to odor discrimination. © 1995 Wiley-Liss, Inc.     

Simultaneous up-regulation of neurofilament proteins during the postnatal development of the rat nervous system

The expression of neurofilament (NF) proteins was examined during postnatal development of the rat nervous system in order to elucidate the nature of NF expression during the period of transition from the embryonic (immature) to the adult (mature) stages of NF expression. mRNAs to the light (NF-L), mid-sized (NF-M), and heavy (NF-H) NF proteins were compared by Northern blots and by in situ hybridizations, in NF-rich (i.e., DRG, spinal cord and brainstem) and in NF-poor (i.e., cerebellum and cerebral cortex) regions of the developing rat nervous system. NF proteins were analyzed by gel electrophoresis and by immunoblots. In each tissue, the expression of NF-H was delayed compared to that of NF-L and NF-M, as previously reported. The present study now shows that the delayed expression of NF-H is accompanied by parallel up-regulations in the expressions of NF-L and NF-M, both at the levels of mRNA and protein. Similar rates of increase of all three NF mRNAs occur between postnatal days 5 (P5) and 24 (P24) in rat spinal cord and DRG. Furthermore, the postnatal up-regulation of NF expression is characterized by a progressive accumulation of all three NF proteins in the tissues. The findings indicate that the adult pattern of NF expression (with high levels of expression of all three NF proteins) becomes established during the postnatal period of development, raising questions as to the nature of factors that coregulate the expression of NF subunits.     

Temporal lobe epilepsy with and without psychosis: exploration of hippocampal pathology including that in subpopulations of neurons defined by their content of immunoreactive calcium-binding proteins

We have investigated relationships between hippocampal/temporal lobe neuropathology and psychosis in subjects with temporal lobe epilepsy, paying particular attention to possible differences in density of hippocampal neurons immunoreactive for calcium-binding proteins. There was a trend for a greater prevalence of left handedness in the psychotic (n = 6) than the non-psychotic (n = 26) cases (P = 0.0504). Psychotic cases also differed from non-psychotic ones in having: (1) more focal lesions outside the hippocampus (P = 0.006); (2) less severe CA1 neuron loss (P = 0.015); and (3) a trend, after Bonferroni correction, for a higher density of calbindin-immunoreactive neurons in the CA4 (P = 0.022). An additional finding was that dentate granule cell dispersion was significantly associated with the presence of a reduced density of calretinin-immunoreactive neurons in CA4 (P = 0.002) and with a more severe loss of CA4 neurons visible with Nissl stain (P = 0.003). Thus, cases of temporal lobe epilepsy with psychosis were distinguishable on the basis of a higher density of calbindin-reactive neurons in CA4 as well as on more general aspects of their pathology. Received: 18 March 1999 / Revised: 30 August 1999 / Accepted: 6 September 1999     

Embryonic and postnatal development of GABA, calbindin, calretinin, and parvalbumin in the mouse claustral complex

We analyzed the development of immunoreactive expression patterns for the neurotransmitter gamma-aminobutyric acid (GABA) and the calcium-binding proteins calbindin, calretinin, and parvalbumin in the embryonic and postnatal mouse claustral complex. Each calcium-binding protein shows a different temporal and spatial pattern of development. Calbindin-positive cells start to be seen very early during embryogenesis and increase dramatically until birth, thus becoming the most abundant cell type during embryonic development, especially in the ventral pallial part of the claustrum. The distribution of calbindin neurons throughout the claustrum during embryonic development partly parallels that of GABA neurons, suggesting that at least part of the calbindin neurons of the claustral complex are GABAergic and originate in the subpallium. Parvalbumin cells, on the other hand, start to be seen only postnatally, and their number then increases while the density of calbindin neurons decreases. Based on calretinin expression in axons, the core/shell compartments of the dorsal claustrum start to be clearly seen at embryonic day 18.5 and may be related to the development of the thalamoclaustral input. Comparison with the expression of Cadherin 8, a marker of the developing dorsolateral claustrum, indicates that the core includes a central part of the dorsolateral claustrum, whereas the shell includes a peripheral area of the dorsolateral claustrum, plus the adjacent ventromedial claustrum. The present data on the spatiotemporal developmental patterns of several subtypes of GABAergic neurons in the claustral complex may help for future studies on temporal lobe epilepsies, which have been related to an alteration of the GABAergic activity.     

Angioarchitectonics of rat cerebellar cortex during pre- and postnatal development

Summary The adult arrangement and the development of stem vessels and capillaries was studied in the rat cerebellum. In principle, stem vessels branch and terminate at three levels: (1) the molecular layer, (2) the Purkinje cell-granular layer, and (3) the cerebellar white matter. All stem vessels are interconnected by the capillary network which is most dense in the Purkinje cell—granular layer. As in the neocortex, the stem vessels of the cerebellum are formed successively during development, so that the later they are formed the more superficial are their terminations. The formation of multiple stem vessels in the depths of fissures and sulci during both pre- and postnatal development may correlate to regional variations in, e.g., mitotic frequency or thickness of the external granular layer. The earliest endo-parenchymal branches are formed before the first neurons are present. Capillary growth by sprouting during the postnatal period parallels known regional differences in the timing of the neuronal maturation, e.g., increased synaptic density and oxidative metabolism. The findings in this investigation confirm and extend the results of an earlier morphometric study on capillary development in the cerebellar cortex. Although the angiogenetic factors remain unknown, the hypothesis of a link between the vascularization and the functional maturation of the brain is corroborated by the results. Knowledge of the normal vascular development seems necessary for an understanding of brain morphogenesis and for interpretation of primary pathogenetic mechanisms in various intoxications etc.     

Developmental changes in somatostatin-positive interneurons in a freeze-lesion model of epilepsy

Somatostatin-expressing (SS) cells are inhibitory interneurons critical to the regulation of excitability in the cerebral cortex. It has been suggested in several animal models of epilepsy that the activity of these neurons reduces the occurrence and strength of epileptiform activity. The physiological properties of SS cells further support these hypotheses. Freeze lesions of neonatal rats serve as a model of human polymicrogyria, which is often characterized by severe seizures. Here we investigate the effects of neonatal freeze lesions on SS-expressing neurons by measuring their densities in control and lesioned hemispheres at two ages. We found that in late juveniles (P30–P32), SS-expressing neurons were depleted by 20% in areas adjacent to the freeze lesion, but at an earlier developmental age (P14-15), there was no significant loss. Since the deficit in SS-expressing neurons occurs well after the onset of epileptiform activity (P12–P18), we conclude that the death of these interneurons does not initiate hyperexcitability in this model.     

Ectopic neurones in the hippocampus of the postnatal rat exposed to methylazoxymethanol during foetal development

Summary Ectopic neurones have been detected in the hippocampus of postnatal hooded rats aged 5–24 days. These rats were exposed to methylazoxymethanol acetate (MAMac) during foetal development by injecting the mother rats with this neurotoxin. At birth, the hippocampus of rats exposed to MAMac showed a normal cytoarchitecture; ectopic neurones became prevalent from 5 days onwards. These ectopic neurones were restricted to subfields CA 1–2 of Ammon's horn, and evidence is presented which suggests that these ectopic sites are formed by neuronal emigration from stratum pyramidale.Ectopic neurones have been shown to occur in genetic abnormalities of man, and in the mutant mouse reeler.MAMac is a powerful methylating agent especially for guanine which is present in DNA and RNA. It is postulated that viable cells with an altered DNA/RNA state may in some way be predisposed to the formation of ectopic cell clusters after a latent period. The movement of neurones from stratum pyramidale provides a convenient animal model for investigating the mechanisms by which ectopic neuronal sites are formed by abnormal migratory patterns.     

Neuropeptide-containing neurons in the endopiriform region of the rat: morphology and colocalization with calcium-binding proteins and nitric oxide synthase

The endopiriform nucleus, further divided into dorsal and ventral parts, and the neighbouring pre-endopiriform (pEn) nucleus form a region of highly heterogeneous structure involved in numerous physiological and pathological processes. Nonpyramidal neurons of this region containing three neuropeptides-somatostatin (SOM), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP)-were examined in this study. Their colocalization with three calcium-binding proteins-parvalbumin (PV), calbindin D28k (CB), calretinin (CR), and with nitric oxide synthase (NOS), was investigated by qualitative and quantitative methods. The results are summarized as follows: (1) all studied substances are distributed in neurons of the entire region, (2) SOM-ir neurons constitute the most numerous neuropeptide-containing population, whereas NOS-ir neurons make up the largest population of all studied, (3) colocalizations are found in the endopiriform region (Enr) (SOM with CB, PV and NOS; VIP with CR; NPY with NOS and NOS with CR), (4) heterogeneity of the endopiriform region appears in the differences of cells' shape distributions of single-labeled (SOM-, CR-PV-ir) and double-labeled (SOM/CB-, SOM/PV-, NPY/NOS- and NOS/CR-ir) neurons, as well as in differentiated percentage values of SOM/NOS, NPY/NOS and VIP/CR double-labeled neurons in three studied parts; additionally, differences in distribution of immunoreactive neuropil elements between parts of the region are observed. Numerous regional differences concerning neuronal morphology and immunocytochemical characteristics justify further division of the endopiriform region into distinguished parts. Some immunocytochemical features of the neurons in studied region may contribute to the role in epileptogenesis.     

Colocalization of CART peptide with prodynorphin and dopamine D1 receptors in the rat nucleus accumbens

CART peptide is a peptidergic neurotransmitter that is expressed in brain regions involved in critical biological processes such as feeding and stress, and in areas associated with drug reward and abuse including the dopamine-rich nucleus accumbens (NAcc), which can be considered part of the basal ganglia. Because CART has been shown to colocalize with substance P, a marker of the basal ganglia direct pathway, we now test for colocalization with other markers of the direct pathway to determine if CART colocalizes with dynorphin and dopamine D1 receptors. In the NAcc, CART peptide immunoreactivity (IR) was colocalized with prodynorphin-IR in neurons. Approximately 80.1% of CART-IR cells colocalized with prodynorphin-IR, while only 27.6% of prodynorphin-IR neurons contained CART-IR, suggesting that CART cells are a subset of dynorphin cells. In contrast, only about 25% of CART-IR cell bodies demonstrated dopamine D1 receptor-IR. Because dynorphin and D1 receptors are markers for the basal ganglia direct pathway, from the NAcc to the basal ganglia output nuclei, and because CART significantly colocalizes with these markers, some CART neurons are part of the direct pathway or some comparable pathway in the accumbens. The presence of CART in NAcc neurons and the fact that NAcc projection neurons have extensive local collaterals suggest that CART may have effects in both terminal and cell body regions of the accumbens and may therefore affect information processing in the NAcc by modulating accumbal neurons.     

Expression of calcium-binding proteins in the proliferative zones around the corticostriatal junction of rabbits during pre- and postnatal development

Herein we asked whether cells expressing calcium-binding proteins around the corticostriatal junction are of pallial or subpallial origin. Brains of rabbit embryos between embryonic day E18 and E28 and postnatal day 0-P22 were immunoreacted with monoclonal antibodies raised against calretinin, calbindin and parvalbumin. At E18-E21, calbindin- and calretinin-immunoreactive cells were seen in distinct proliferative zones in the vicinity of the corticostriatal junction. Whereas calbindin-immunoreactive neurons were in the ventricular zone of the ventral pallium (the medial wall of the lateral ventricular angle), calretinin-immunoreactive cells were, nearby, in the subventricular zone of the subpallium at the lateral edge of the lateral ganglionic eminence. From E25 to P22, both calbindin- and calretinin-immunoreactive cells appeared in the pallial ventricular and subventricular zones around the lateral ventricular angle. Some of these cells resembled migratory neuroblasts. Parvalbumin-immunoreactive cells appeared at P5-P10, albeit they were almost negligible in the proliferative zones around the corticostriatal junction and the lateral ventricular angle. The results suggest that a number of the calbindin-expressing neurons that are generated in mid-gestation and postnatally are of pallial origin. They also indicate that only a few of the late-generated calretinin-immunoreactive cells may have a pallial source. The origin of the parvalbumin-immunoreactive cells was not ascertained in the present study.     

Localization of synapse-associated proteins during postnatal development of the rat retina.

The expression of synapse-associated proteins (SAPs) was monitored throughout postnatal development of the rat retina using specific antibodies and immunocytochemistry. The distribution of chapsin-110/postsynaptic density protein (PSD)-93, SAP90/PSD-95, SAP97 and SAP102 immunoreactivity was characterized. All SAPs were found to be expressed in the inner plexiform layer (IPL) from birth on or soon after birth. With the exception of SAP97, the IPL labelling changed from a diffuse pattern staining the whole developing IPL to the typical adult punctate synaptic staining in the second postnatal week. Staining in the outer retina was first observed at postnatal day 5 (P5) for all proteins at the onset of outer plexiform layer (OPL) development. All SAPs showed a differential cellular and temporal distribution being either exclusively pre- or postsynaptically localized. Except for SAP90/PSD-95, immunoreactivity was also detected in the nerve fibre layer throughout postnatal development. Possible functions of the early expression of SAPs well before differentiation and maturation of glutamatergic ribbon synapses are discussed.     

Histochemical distribution of acid glycosaminoglycans in rat cerebellum during postnatal development: Neuropile

Developmentally regulated modifications of glycosaminoglycans (GAGs) in the central nervous system (CNS) have suggested that also in the CNS, these compounds might participate in morphogenesis and nerve cell differentiation. However very few studies have been reported concerning the regional distribution of these compounds by histochemical techniques. We have used the Alcian Blue staining method also in conjunction with enzymatic digestion and with a technique which allowed the measurement of the degree of GAG sulphatation. The combination of the three techniques showed that during the first week GAGs, presumed to be hyaluronic acid, are localized throughout the neuropile of the entire cerebellum and especially in the medullary region. Sulphated glycans appear later in the medullary region (particularly at the border between the medullary region and the internal granular layer) and in all the layers of cerebellum (in particular around the Purkinje and deep cerebellar nuclei neurons and possibly in the cerebellar glomeruli). Sulphated glycans in the medullary region disappear around the 12th day when myelination starts. The transient presence of glycoproteins in the molecular layer was also detected.     

Distribution of calcium-binding proteins in the cerebellum

Calcium plays a fundamental role in the cell as second messenger and is principally regulated by calcium-binding proteins. Although these proteins share in common their ability to bind calcium, they belong to different subfamilies. They present, in general, specific developmental and distribution patterns. Most Purkinje cells express the fast and slow calcium buffer proteins calbindin-D28k and parvalbumin, whereas basket, stellate and Golgi cells the slow buffer parvalbumin only. They are, almost all, calretinin negative. Granule, Lugaro and unipolar brush cells present an opposite immunoreactivity profile, most of them being calretinin positive while lacking calbindin-D28k and parvalbumin. The developmental pattern of appearance of these proteins seems to follow the maturation of neurons. Calbindin-D28k appears early, shortly after cessation of mitosis when neurons become ready to start migration and differentiation while parvalbumin is expressed later in parallel with an increase in neuronal activity. The other proteins are generally detected later. During development, some of these proteins, like calretinin, are transiently expressed in specific cellular subpopulations. The function of these proteins is not fully understood, although strong evidence supports a prominent role in physiological settings with altered calcium concentrations. These proteins regulate and are regulated by intracellular calcium level. For example, they may directly or indirectly enable sensitization or desensitization of calcium channels, and may further block calcium entry into the cells, like the calcium-sensor proteins, that have been shown to be potent and specific modulators of ion channels, which may allow for feedback control of current function and hence signaling. The absence of calcium buffer proteins results in marked abnormalities in cell firing; with alterations in simple and complex spikes or transformation of depressing synapses into facilitating synapses. Calcium-binding protein implication in resistance to degeneration is still a controversial issue. Neurons rich in calcium-binding proteins, especially calbindin-D28k and parvalbumin, seem to be relatively resistant to degeneration in a variety of acute and chronic disorders. However other data support that an absence of calcium-binding proteins may also have a neuroprotective effect. It is not unlikely that neurons may face a dual action mechanism where a decrease in calcium-binding proteins has a first short-term beneficial effect while it becomes detrimental for the cell over the long term.     

Differentiation in the immunocytochemical features of intrinsic and cortically projecting neurons in the rat claustrum — combined immunocytochemical and axonal transport study

Retrograde axonal transport method of the fluorescent tracer FluoroGold (FG) was combined with immunocytochemistry to investigate the occurrence of nitric oxide synthase (NOS), somatostatin (SOM), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) in both intrinsic and cortically projecting neurons of the rat claustrum. Only NOS was detected in both the scattered projecting neurons and internal neurons of the claustrum. Approximately 20% of NOS-immunoreactive neurons in the claustrum were also retrogradely labeled with FG after tracer injections into the frontal cortex. The other substances were exclusively confined to the population of interneurons, which mainly displayed an oval, round or fusiform shape and a medium size. Apart from the neuronal somata, the proximal parts of the dendritic arborization were clearly visible. The immunoreactive neurons were randomly distributed in the claustrum and their neuronal size and shape did not differ in the various parts of the studied structure. Co-localization of NOS and SOM or NOS and NPY was reported. In conclusion, SOM, VIP and NPY do not appear to play a significant role in the claustro-cortical projection but are most probably involved in modulation and information transfer in the claustrum. The appearance of NOS in both cortically projecting and intrinsic neurons of the claustrum may be indicative of a fundamentally different role in the functioning of the claustro-cortical loop.     

大鼠高眼压后视网膜内三种钙结合蛋白免疫活性的改变

目的:通过高眼压诱导的视网膜缺血模型和免疫组化方法,探讨parvalbumin(PV),calbindin(CB)和calretinin(CR)三种钙结合蛋白在缺血后视网膜中的表达.方法:24只大鼠(分4组,每组6只)的右眼眼内压升高至14.6 kPa(110 mmHg),维持90 min;左眼作对照.分别存活0,2,7,14 d后处死.其视网膜冷冻切片后,分别作CB、PV和CR的免疫组化反应;邻片用焦油紫染色.结果:在正常视网膜,PV和CB主要表达于内核层;CR表达于内核层、节细胞层和内网层.缺血0 d组中,PV在内核层的表达剧减,而CB和CR仅轻微减少.2 d后,CB和CR明显减少;而PV的表达开始逐渐恢复.至第14天,尽管内核层神经元已减少了1/2,但PV的表达已恢复至正常水平,其阳性神经元与尼氏染色神经元数之比是正常的2倍.同样,相对第7天而言,CB和CR的表达也有一定程度的恢复.结论:PV,CB和CR的阳性神经元对缺血敏感程度不同,且在一定的实验条件下其表达是可逆的.     

Postnatal development of parvalbumin and calbindin D-28k immunoreactivities in the canine anterior cingulate cortex: transient expression in layer V pyramidal cells

We have examined the ontogeny of parvalbumin (PV) and calbindin D-28k (CB) immunoreactivities in the canine anterior cingulate cortex (ACC) from the day of birth (P0) through P180. At P7, PV immunoreactivity first appeared in layer VI multipolar cells. The PV immunoreactivity in GABAergic nonpyramidal cells appeared to follow an inside-out gradient of radial emergence. Although immunoreaction was limited mainly to the developing nonpyramidal cells, pyramid-like PV immunoreactive cells were transitorily observed in layer V from P14 to P90. The developmental pattern of CB immunoreactivity differed from that of PV immunoreactivity. CB immunoreactivity first developed in layer V pyramidal cells from P0, which continued through P90. CB immunoreactive nonpyramidal cells were located in the infragranular layers and white matter at P0 and maturated in both the supragranular and infragranular layers without clear inside-out gradient.This developmental study revealed the comparable belated expression of PV immunoreactivity and the transient expression of both calcium-binding proteins in layer V pyramidal cells. These results suggest that the transient expression of calcium-binding proteins in layer V pyramidal cells might be related to the critical period of early postnatal development.