The dynamic developmental localization of the full-length corticotropin-releasing factor receptor type 2 in rat cerebellum

Corticotropin releasing factor receptor 2 (CRF-R2) is strongly expressed in the cerebellum and plays an important role in the development of the cerebellar circuitry, particularly in the development of the dendritic trees and afferent input to Purkinje cells. However, the mechanisms responsible for the distribution and stabilization of CRF-R2 in the cerebellum are not well understood. Here, we provide the first detailed analysis of the cellular localization of the full-length form of CRF-R2 in rat cerebellum during early postnatal development. We document unique and developmentally regulated subcellular distributions of CRF-R2 in cerebellar cell types, e.g. granule cells after postnatal day 15. The presence of one or both receptor isoforms in the same cell may provide a molecular basis for distinct developmental processes. The full-length form of CRF-R2 may be involved in the regulation of the first stage of dendritic growth and at later stages in the controlling of the structural arrangement of immature cerebellar circuits and in the autoregulatory pathway of the cerebellum.     

Corticotropin-releasing factor receptor types 1 and 2 are differentially expressed in pre- and post-synaptic elements in the post-natal developing rat cerebellum

Corticotropin-releasing factor (CRF)-like proteins act via two G-protein-coupled receptors (CRF-R1 and CRF-R2) playing important neuromodulatory roles in stress responses and synaptic plasticity. The cerebellar expression of corticotropin-releasing factor-like ligands has been well documented, but their receptor localization has not. This is the first combination of a light microscopic and ultrastructural study to localize corticotropin-releasing factor receptors immunohistologically in the developing rat cerebellum. Both CRF-R1 and CRF-R2 were expressed in climbing fibres from early stages (post-natal day 3) to the adult, but CRF-R2 immunoreactivity was only prominent throughout the molecular layer in the posterior cerebellar lobules. CRF-R1 immunoreactivity was concentrated in apical regions of Purkinje cell somata and later in primary dendrites exhibiting a diffuse cytoplasmic appearance. In Purkinje cells, CRF-R1 immunoreactivity was never membrane bound post-synaptically in dendritic spines while CRF-R2 immunoreactivity was found on plasmic membranes of Purkinje cells from post-natal day 15 onwards. We conclude that the localization of these receptors in cerebellar afferents implies their pre-synaptic control of the release of corticotropin-releasing factor-like ligands, impacting on the sensory information being transmitted from afferents. Furthermore, the fact that CRF-R2 is membrane bound at synapses, while CRF-R1 is not, suggests that ligands couple to CRF-R2 via synaptic transmission and to CRF-R1 via volume transmission. Finally, the distinct expression profiles of receptors along structural domains of Purkinje cells suggest that the role for these receptors is to modulate afferent inputs.     

Evidence for an axonal localization of the type 2 corticotropin-releasing factor receptor during postnatal development of the mouse cerebellum

Previous studies have described the embryonic and postnatal development of CRF, as well as the type 1 CRF receptor in the mouse cerebellum. The present immunohistochemical study localizes the cellular distribution of the type 2 CRF receptor (CRF-R2) during postnatal development of the mouse cerebellum. Western blot analysis indicates that the antibody used in this analysis recognizes both a full-length and a truncated isoform of the type 2 receptor. We propose that each isoform has a unique cellular distribution. In the present study, the postnatal (P) development (P0-P14) and cellular localization of CRF-R2 in different cell types was analyzed using PAP and double-label fluorescent immunohistochemistry; cell-specific antibodies were used to identify cells expressing CRF-R2 at different stages of postnatal development. At P0, CRF-R2 immunoreactivity was localized within the somata of Purkinje cells and migrating GABAergic interneurons. CRF-R2 was first observed in the initial axonal segments of some Purkinje cells at P5, and was evident in many Purkinje cell axon hillocks at P8. Punctate immunoreactivity is present in the molecular layer by P5 and is interpreted to be immunolabeled parallel fibers. Between P8 and P14, CRF-R2 immunostaining is present in the initial axonal segments of Golgi cells, within the internal granule cell layer. Finally, CRF-R2 is present in both radial glia in the molecular layer as well as in astrocytes in the white matter and internal granule cell layer from P5 to P14. The present results suggest that CRF-R2, both the truncated and the full-length isoforms, are present in the developing cerebellum, each with a unique cellular distribution. The immunohistochemical evidence indicates that the truncated isoform of the type 2 CRF receptor is in the axons of several different types of cerebellar cortical neurons, and suggests that CRF could play a role in cerebellar development by modulating the release of transmitters from excitatory and/or inhibitory interneurons, which in turn could directly alter the maturation of cerebellar circuits. In contrast, the binding of a ligand to the full-length isoform of CRF-R2 or to CRF-R1, both in a postsynaptic location, may have a more direct effect on regulating the responsiveness of these cells to growth factors or neurotransmitters released from afferent axons by regulating permeability of ion channels or altering second messenger systems.     

Immunocytochemical localization of the alpha 1A subunit of the P/Q-type calcium channel in the rat cerebellum

Among various types of low- and high-threshold calcium channels, the high voltage-activated P/Q-type channel is the most abundant in the cerebellum. These P/Q-type channels are involved in the regulation of neurotransmitter release and in the integration of dendritic inputs. We used an antibody specific for the alpha1A subunit of the P/Q-type channel in quantitative pre-embedding immunogold labelling combined with three-dimensional reconstruction to reveal the subcellular distribution of pre- and postsynaptic P/Q-type channels in the rat cerebellum. At the light microscopic level, immunoreactivity for the alpha1A protein was prevalent in the molecular layer, whereas immunostaining was moderate in the somata of Purkinje cells and weak in the granule cell layer. At the electron microscopic level, the most intense immunoreactivity for the alpha1A subunit was found in the presynaptic active zone of parallel fibre varicosities. The dendritic spines of Purkinje cells were also strongly labelled with the highest density of immunoparticles detected within 180 nm from the edge of the asymmetrical parallel fibre-Purkinje cell synapses. By contrast, the immunolabelling was sparse in climbing fibre varicosities and axon terminals of GABAergic cells, and weak and diffuse in dendritic shafts of Purkinje cells. The association of the alpha1A subunit with the glutamatergic parallel fibre-Purkinje cell synapses suggests that presynaptic channels have a major role in the mediation of excitatory neurotransmission, whereas postsynaptic channels are likely to be involved in depolarization-induced generation of local calcium transients in Purkinje cells.     

Deficient long-term synaptic depression in the rostral cerebellum correlated with impaired motor learning in phospholipase C beta4 mutant mice

Long-term depression (LTD) at parallel fibre-Purkinje cell synapse of the cerebellum is thought to be a cellular substrate for motor learning. LTD requires activation of metabotropic glutamate receptor subtype 1 (mGluR1) and its downstream signalling pathways, which invariably involves phospholipase Cbetas (PLCbetas). PLCbetas consist of four isoforms (PLCbeta1-4) among which PLCbeta4 is the major isoform in most Purkinje cells in the rostral cerebellum (lobule 1 to the rostral half of lobule 6). We studied mutant mice deficient in PLCbeta4, and found that LTD was deficient in the rostral but not in the caudal cerebellum of the mutant. Basic properties of parallel fibre-Purkinje cell synapses and voltage-gated Ca2+ channel currents appeared normal. The mGluR1-mediated Ca2+ release induced by repetitive parallel fibre stimulation was absent in the rostral cerebellum of the mutant, suggesting that their LTD lesion was due to the defect in the mGluR1-mediated signalling in Purkinje cells. Importantly, the eyeblink conditioning, a simple form of discrete motor learning, was severely impaired in PLCbeta4 mutant mice. Wild-type mice developed the conditioned eyeblink response, when pairs of the conditioned stimulus (tone) and the unconditioned stimulus (periorbital shock) were repeatedly applied. In contrast, PLCbeta4 mutant mice could not learn the association between the conditioned and unconditioned stimuli, although their behavioural responses to the tone or to the periorbital shock appeared normal. These results strongly suggest that PLCbeta4 is essential for LTD in the rostral cerebellum, which may be required for the acuisition of the conditioned eyeblink response.     

Differential roles of corticotropin-releasing factor receptor subtypes 1 and 2 in opiate withdrawal and in relapse to opiate dependence

The possible effects on the morphine withdrawal signs of the nonspecific corticotropin-releasing factor (CRF) receptor antagonist alpha-helical CRF, the selective CRF receptor subtype 1 antagonist CP-154,526 and the selective CRF receptor subtype 2 antagonist antisauvagine-30 (AS-30) were investigated in rats. The most withdrawal signs, including jumping, teeth chatter, writhing, shakes, lacrimation, piloerection, irritability and diarrhoea, were attenuated by pretreatment with alpha-helical CRF (10 microg i.c.v.) and CP-154,526 (30 mg/kg i.p.). However, no morphine withdrawal signs except for diarrhea were significantly affected by pretreatment with AS-30 (10 microg, i.c.v.). To investigate the possible role of different CRFR antagonists (alpha-helical CRF, CP-154,526 and AS-30) in relapse to opiate dependence, the 28-day extinction of morphine-conditioned place preference (CPP) was used. The morphine-CPP disappeared following a 28-day extinction and then was reactivated by a single injection of 10 mg/kg morphine. Pretreatment with alpha-helical CRF (10 microg, i.c.v.) and CP-154, 526 (30 mg/kg, i.p.) could significantly block this reactivation of morphine-CPP. In contrast, pretreatment with AS-30 (1 or 10 microg i. c.v.) did not affect this reactivation of morphine-CPP. The present study demonstrated that activation of the CRF receptor is involved in morphine withdrawal signs and relapse to morphine dependence, and that the role of CRF receptor subtypes 1 and 2 in withdrawal and reactivation of morphine dependence is not identical. CRF receptor subtype 1, but not subtype 2, is largely responsible for the action of the CRF system on opiate dependence. These results suggest that the CRF receptor antagonists, particularly the CRF receptor subtype 1 antagonist, might be of some value in the treatment and prevention of drug dependence.     

Locomotor suppressive and anxiolytic-like effects of urocortin 3, a highly selective type 2 corticotropin-releasing factor agonist

Murine urocortin 3 (mUcn 3), a member of the corticotropin releasing factor (CRF) peptide family, was recently identified. Of known agonists, this neuropeptide displays the highest degree of selectivity in binding to the CRF₂ receptor. These experiments sought to test the hypothesis that CRF₂ receptors have a role in modulating stress by examining intracerebroventricular (i.c.v.) administration of mUcn 3 in animal models of activation and anxiety. To investigate the effects of mUcn 3 on motor activity, rats were injected with mUcn 3 (0, 0.1, 1.0 or 10 μg, i.c.v.) 10 min prior to testing and activity was monitored for 6 h. To determine changes in novelty-induced exploration, rats were injected with mUcn 3 (0, 0.1, 1.0 or 10 μg, i.c.v.) 10 min prior to testing and examined in the elevated plus maze. Finally, delayed effects of mUcn 3 were tested in rats injected with 1.0 μg of mUcn 3 or vehicle 30 or 60 min prior to testing in the elevated plus maze. Injections of mUcn 3 significantly decreased locomotor activity in rats during the first hour of testing. In the elevated plus maze, mUcn 3 injections significantly increased open arm preference compared to vehicle when tested using a 10-min pretreatment interval. mUcn treated rats tested in the elevated plus maze following the delayed pretreatment interval did not differ from controls. These data demonstrate that injection of mUcn 3 leads to acute locomotor suppressive effects and decreases in stress-like behaviors, indicating an anxiolytic-like action for mUcn 3, and suggests a possible role of the CRF₂ receptor in the regulation of stress-related behavior.     

Distribution of corticotropin-releasing factor in the cerebellum and precerebellar nuclei of the opossum: a study utilizing immunohistochemistry, in situ hybridization histochemistry, and receptor autoradiography

This study reports 1) a nonhomogeneous distribution of three morphologically distinct, corticotropin-releasing factor (CRF)-immunoreactive axonal phenotypes within the cerebellum of the opossum: climbing fibers, mossy fibers, and beaded fibers within the ganglionic plexus; 2) the existence of CRF binding sites within the cerebellar cortex; and 3) the distribution of CRF-containing neurons in brainstem precerebellar nuclei identified with immunohistochemistry and in situ hybridization histochemistry. CRF-immunoreactive climbing and/or mossy fibers were identified within all cerebellar lobules. The density of CRF-immunoreactive fibers was greatest in the vermis, where longitudinal bands of intensely immunoreactive climbing and mossy fibers were interspersed with regions containing fibers demonstrating lower levels of immunolabeling. CRF-immunoreactive fibers were present within all deep cerebellar nuclei. The topography of CRF-containing cerebellar fibers is discussed with respect to possible sites of origin within the brainstem. CRF-immunoreactive neurons were identified in all nuclei of the inferior olivary complex, although the number and intensity of immunostaining of CRF-containing cells varied within and among individual nuclei. CRF-immunoreactive somata were also present in brainstem nuclei known to give rise to cerebellar mossy fibers. In situ hybridization histochemistry utilizing an 35S-labeled synthetic 48-base oligodeoxynucleotide complementary to amino acids 22-37 of rat CRF proper revealed that CRF mRNA is transcribed in precerebellar nuclei. Variation in the level of CRF mRNA was detected among inferior olivary nuclei, in correspondence with variations detected in the levels of immunostaining. Data from this study suggest that variation in the level of CRF immunoreactivity detected within cerebellar afferent fibers may correlate with the level of CRF mRNA within cell bodies of origin of the projections. In vitro receptor autoradiography, utilizing 125I-Tyro-ovine CRF, revealed correspondence between CRF binding sites and CRF-immunoreactive fibers in the cerebellar cortex. Results of this study support suggestions for CRF-mediated circuitry in the cerebellum.     

The glutamate receptor delta 2 in relation to cerebellar development and plasticity

Understanding what are the mechanisms that strengthen, stabilize and restrict synaptic innervation is a relevant topic in glutamate receptor delta 2 (GluRδ2)-related research. It also involves targeting and selection of afferent input during formation of the neuronal circuitry in the cerebellar cortex and its functioning. This review will focus on the role of GluRδ2, one of the main players in this field. Special emphasis will be placed on the processes that regulate the rapid translocation from climbing fibres to parallel fibres of GluRδ2 and the role of GluRδ2 in the reduction of supernumerary climbing fibre contacts on a single Purkinje cell. Furthermore, GluRδ2 knockout mice show ataxia and impaired motor coordination, suggesting that the presence of GluRδ2 plays an important role in controlling cerebellar functioning.     

Diversity of cellular physiology and morphology of Purkinje cells in the adult zebrafish cerebellum

This study was designed to explore the functional circuitry of the adult zebrafish cerebellum, focusing on its Purkinje cells and using whole-cell patch recordings and single cell labeling in slice preparations. Following physiological characterizations, the recorded single cells were labeled for morphological identification. It was found that the zebrafish Purkinje cells are surprisingly diverse. Based on their physiology and morphology, they can be classified into at least three subtypes: Type I, a narrow spike cell, which fires only narrow Na⁺ spikes (<3 ms in duration), and has a single primary dendrite with an arbor restricted to the distal molecular layer; Type II, a broad spike cell, which fires broad Ca²⁺ spikes (5–7 ms in duration) and has a primary dendrite with limited branching in the inner molecular layer and then further radiates throughout the molecular layer; and Type III, a very broad spike cell, which fires very broad Ca²⁺ spikes (≥10 ms in duration) and has a dense proximal dendritic arbor that is either restricted to the inner molecular layer (Type IIIa), or radiates throughout the entire molecular layer (Type IIIb). The graded paired-pulse facilitation of these Purkinje cells’ responses to parallel fiber activations and the all-or-none, paired-pulse depression of climbing fiber activation are largely similar to those reported for mammals. The labeled axon terminals of these Purkinje cells end locally, as reported for larval zebrafish. The present study provides evidence that the corresponding functional circuitry and information processing differ from what has been well-established in the mammalian cerebellum.     

Reduced anxiety-like and cognitive performance in mice lacking the corticotropin-releasing factor receptor 1

Corticotropin-releasing factor (CRF) has been hypothesized to be involved in the pathophysiology of anxiety, depression, cognitive and feeding disorders. Two distinct CRF receptor subtypes, CRFR1 and CRFR2, are thought to mediate CRF actions in the CNS. However, the role for each receptor subtype in animal models of neuropsychiatric disorders remains to be determined. Using CRFR1 deficient mice, the present study investigated the functional significance of this CRF receptor subtype in anxiety-like and memory processes. CRFR1 knockout mice displayed an increased exploratory behavior in both the Elevated Plus-maze (EPM) and the Black and White (B–W) test box models of anxiety, indicating an anxiolytic-like effect of the CRFR1 gene deletion. In contrast, during the retrieval trial of a two-trial spatial memory task wild type mice made more visits to and spent more time in the novel arm as opposed to the two familiar ones of a Y-maze apparatus. No increase in the level of exploration of the novel arm by the CRFR1 deficient mice was observed. This indicates that CRFR1 knockout mice are impaired in spatial recognition memory. These results demonstrate that genetic deletion of the CRFR1 receptor can lead to impairments in anxiety-like and cognitive behaviors, supporting a critical role for this receptor in anxiety and cognitive biological processes.     

Role of corticotropin-releasing factor and its receptor in nociceptive modulation in the central nucleus of amygdala in rats

Corticotropin-releasing factor (CRF) plays important physiological functions in the central nervous system. The present study was performed to investigate the role of CRF and CRF receptor in nociceptive modulation in the central nucleus of amygdala (CeA) of rats. The hindpaw withdrawal latency (HWL) to noxious thermal and mechanical stimulation increased significantly after intra-CeA administration of 0.1 and 0.01 nmol of CRF, but not 0.001 nmol, indicating that CRF induces antinociceptive effects in the CeA of rats. The antinociceptive effect may be due to the dose of CRF was attenuated by intra-CeA administration of 0.1 nmol alpha-hCRF9-41, a selective CRF receptor antagonist, suggesting that the CRF-induced antinociception is mediated by the CRF receptors in the CeA. Furthermore, the HWL to both thermal and mechanical stimulation decreased significantly after intra-CeA administration of alpha-hCRF9-41 alone, suggesting an involvement of endogenous CRF in the CeA in nociceptive modulation. The present study demonstrated that both exogenous and endogenous CRF plays an antinociceptive effect in the CeA, the effect is mediated by CRF receptor.     

Suppression of the induction of long-term depression by carbon monoxide in rat cerebellar slices

Carbon monoxide (CO) suppresses brain functions at doses lower than that suppressing oxygen (O(2)) supply to the brain, and the cerebellum is one of the sites most susceptible to the neurotoxic effects of CO. We investigated the effects of CO on the induction of cerebellar long-term depression (LTD) in the synapses between parallel fibres (PFs) and Purkinje cells. CO, at concentrations between 8 nM and 5 microM, exhibited almost no effect on synaptic responses in Purkinje cells, O(2) consumption and NO release from PFs in rat cerebellar slices. However, the induction of LTD was significantly suppressed by CO at concentrations between 40 and 200 nM. The suppressive effect of 40 nM CO was antagonized by 10 microM NOR3, an NO donor. In contrast, CO exhibited no clear effect on the induction of LTD at concentrations between 1 and 5 microM. The induction of LTD, suppressed by 10 microM N(G)-nitro-L-arginine, an inhibitor of NO synthase, was not restored by 5 microM CO. CO is not only a neurotoxic substance but also a candidate for an intercellular messenger. delta-Aminolevulinate (30 microM), a substance facilitating endogenous CO production, suppressed the induction of LTD, and the effect of delta-aminolevulinate was antagonized by 10 microM NOR3. These findings suggest that CO may have a suppressive effect on the induction of cerebellar LTD at nanomolar concentrations, probably via its effects on NO/cGMP signalling.     

Sex-linked roles of the CRF1 and the CRF2 receptor in social behavior

Dysfunctional social behavior is a major clinical feature of mood, anxiety, autism spectrum, and substance-related disorders, and may dramatically contribute to the poor outcome of these diseases. Nevertheless, the mechanisms underlying social behavior deficits are still largely unknown. The corticotropin-releasing factor (CRF) system, a major coordinator of the stress response, has been hypothesized to modulate social behavior. CRF signaling is mediated by two receptor types, termed CRF₁ and CRF₂. Using the three-chamber task for sociability (i.e., preference for an unfamiliar conspecific vs. an object), this study demonstrates that CRF₂ receptor null mutation (CRF₂−/−) reduces sociability in female mice but increases it in male mice. Both female and male CRF₂−/− mice display a preference for social odor cues over neutral cues, indicating that sex- and CRF₂ receptor-dependent sociability is not due to altered olfaction or impaired social cues discrimination. Moreover, treatment with the CRF₁ receptor-preferring antagonist, antalarmin, consistently induces sociability in non-social mice but disrupts it in social mice, independently of CRF₂ receptor deficiency. Sex, CRF₂ receptor deficiency, or antalarmin affect locomotor activity during the three-chamber test. However, throughout the study CRF₁ and CRF₂ receptor-linked sociability is independent of locomotor activity. The present findings highlight major functions for the CRF system in the regulation of social behavior. Moreover, they provide initial evidence of sex-linked roles for the CRF₁ and the CRF₂ receptor, emphasizing the importance of sex as a major biological variable to be taken into consideration in preclinical and clinical studies.     

Toll样受体4在小鼠小脑组织中的表达情况分析

目的分析Toll样受体4（TLR4）蛋白在小鼠小脑组织中的表达情况。 方法选取6月龄大小的TLR4基因敲除（TLR4^-/-）小鼠及其同窝对照的野生型（TLR4^+/+）小鼠的小脑组织,制成冰冻切片,通过免疫荧光染色技术检测TLR4在TLR4^+/+小鼠小脑冰冻切片组织中的表达,并利用小脑组织特定细胞的蛋白标记Marker与其共染,TLR4^-/-小鼠小脑冰冻切片作为阴性对照,最后通过激光共聚焦显微镜获取图像并确定TLR4在小脑组织中的表达。 结果TLR4高表达于钙结合蛋白阳性的小脑蒲肯野细胞中,少量表达于离子钙接头蛋白阳性的小胶质细胞中,而在性别决定区Y盒2号蛋白阳性的伯格曼胶质细胞和神经元特异核蛋白阳性的颗粒细胞中并无表达。 结论TLR4高表达于小鼠小脑蒲肯野细胞中,深入分析TLR4在蒲肯野细胞功能执行中的作用,将有助于揭示TLR4在小脑功能执行中的作用。     

Localization of corticotropin-releasing factor, somatostatin, and vasoactive intestinal polypeptide in the parabrachial nuclei of the human brain

The immunocytochemical localizations of corticotropin-releasing factor (CRF), somatostatin (SRIF), and vasoactive intestinal polypeptide (VIP) were studied in the human parabrachial nuclei (PBN) using the avidin-biotin complex (ABC) technique. The brains were obtained from seven adult male human subjects of 38-74 years. In three cases, the brains were fixed within 2 hr, in four cases within 5 hr, postmortem. All of these peptides were detected in fibers through the orocaudal extent of the lateral PBN, whereas the medial nucleus contained only CRF immunoreactive fibers. Immunoreactive fibers were distributed unevenly within the lateral nucleus with the highest density in the dorsal and much fewer in the ventral part of the lateral subdivision. The highest to lowest density of immunostained processes were detected using CRF, SRIF, and VIP antisera, respectively. Since NPB is known as an important relay nucleus for the central autonomic pathway, the presence of the above noted neuropeptides in nerve fibers in this area may suggest a neurotransmitter or neuromodulatory role of CRF, somatostatin, and VIP in certain autonomic nervous mechanism of the human brain.     

Type 1 corticotropin-releasing factor receptor expression reported in BAC transgenic mice: implications for reconciling ligand-receptor mismatch in the central corticotropin-releasing factor system

In addition to its established role in initiating the endocrine arm of the stress response, corticotropin-releasing factor (CRF) can act in the brain to modulate neural pathways that effect coordinated physiological and behavioral adjustments to stress. Although CRF is expressed in a set of interconnected limbic and autonomic cell groups implicated as primary sites of stress-related peptide action, most of these are lacking or impoverished in CRF receptor (CRFR) expression. Understanding the distribution of functional receptor expression has been hindered by the low resolution of ligand binding approaches and the lack of specific antisera, which have supported immunolocalizations at odds with analyses at the mRNA level. We have generated a transgenic mouse that shows expression of the principal, or type 1, CRFR (CRFR1). This mouse expresses GFP in a cellular distribution that largely mimics that of CRFR1 mRNA and is extensively colocalized with it in individual neurons. GFP-labeled cells display indices of activation (Fos induction) in response to central CRF injection. At the cellular level, GFP labeling marks somatic and proximal dendritic morphology with high resolution and is also localized to axonal projections of at least some labeled cell groups. This includes a presence in synaptic inputs to central autonomic structures such as the central amygdalar nucleus, which is implicated as a stress-related site of CRF action, but lacks cellular CRFR1 expression. These findings validate a new tool for pursuing the role of central CRFR signaling in stress adaptation and suggest means by which the pervasive ligand-receptor mismatch in this system may be reconciled.     

Evidence for the role of corticotropin-releasing factor in major depressive disorder

Major depressive disorder (MDD) is a devastating disease affecting over 300 million people worldwide, and costing an estimated 380 billion Euros in lost productivity and health care in the European Union alone. Although a wealth of research has been directed toward understanding and treating MDD, still no therapy has proved to be consistently and reliably effective in interrupting the symptoms of this disease. Recent clinical and preclinical studies, using genetic screening and transgenic rodents, respectively, suggest a major role of the CRF₁ gene, and the central expression of CRF₁ receptor protein in determining an individual's risk of developing MDD. This gene is widely expressed in brain tissue, and regulates an organism's immediate and long-term responses to social and environmental stressors, which are primary contributors to MDD. This review presents the current state of knowledge on CRF physiology, and how it may influence the occurrence of symptoms associated with MDD. Additionally, this review presents findings from multiple laboratories that were presented as part of a symposium on this topic at the annual 2014 meeting of the International Behavioral Neuroscience Society (IBNS). The ideas and data presented in this review demonstrate the great progress that has been made over the past few decades in our understanding of MDD, and provide a pathway forward toward developing novel treatments and detection methods for this disorder.     

Localization of intracellular and plasma membrane Ca2+-ATPases in the cerebellum

The sarco-endoplasmic reticulum Ca2+-ATPase and the plasma membrane Ca2+-ATPase contribute to the regulation of the intracellular Ca2+ concentration. These proteins transport Ca2+ ions into the endoplasmic reticulum and to the extracellular medium, respectively. A different localization of the two families of Ca2+-ATPases has been shown in concrete subcellular areas of Purkinje cells and in other neuronal elements from cerebellum. In the light of the actual knowledge of Ca2+-ATPases, this strict distribution suggests the existence of different demands on Ca2+ homeostasis in these cerebellar and cellular subregions.