Papers by Carla Perrone-capano
International Journal of Molecular Sciences
The development of midbrain dopaminergic (DA) neurons requires a fine temporal and spatial regula... more The development of midbrain dopaminergic (DA) neurons requires a fine temporal and spatial regulation of a very specific gene expression program. Here, we report that during mouse brain development, the microRNA (miR-) 204/211 is present at a high level in a subset of DA precursors expressing the transcription factor Lmx1a, an early determinant for DA-commitment, but not in more mature neurons expressing Th or Pitx3. By combining different in vitro model systems of DA differentiation, we show that the levels of Lmx1a influence the expression of miR-204/211. Using published transcriptomic data, we found a significant enrichment of miR-204/211 target genes in midbrain dopaminergic neurons where Lmx1a was selectively deleted at embryonic stages. We further demonstrated that miR-204/211 controls the timing of the DA differentiation by directly downregulating the expression of Nurr1, a late DA differentiation master gene. Thus, our data indicate the Lmx1a-miR-204/211-Nurr1 axis as a key ...
Structural, functional, and molecular alterations in excitatory spine synapses are a common hallm... more Structural, functional, and molecular alterations in excitatory spine synapses are a common hallmark of many neurodevelopmental disorders including intellectual disability and autism. Here, we describe an optimized methodology, based on combined use of DiI and immunofluorescence, for rapid and sensitive characterization of the structure and composition of spine synapses in native brain tissue. We successfully demonstrate the applicability of this approach by examining the properties of hippocampal spine synapses in juvenile Fmr1 KO mice, a mouse model of Fragile X Syndrome. We find that mutant mice display pervasive dysgenesis of spine synapses evidenced by an overabundance of both abnormally elongated thin spines and cup-shaped spines, in combination with reduced density of mushroom spines. We further find that mushroom spines expressing the actin-binding protein Synaptopodin - a marker for spine apparatus - are more prevalent in mutant mice. Previous work identified spines with Sy...
ACS Chemical Neuroscience, 2022
During the last decade, the kinetics of drug-target interaction has received increasing attention... more During the last decade, the kinetics of drug-target interaction has received increasing attention as an important pharmacological parameter in the drug development process. Several studies have suggested that the lipophilicity of a molecule can play an important role. To date, this aspect has been studied for several G protein-coupled receptors (GPCRs) ligands but not for the 5-HT7 receptor (5-HT7R), a GPCR proposed as a valid therapeutic target in neurodevelopmental and neuropsychiatric disorders associated with abnormal neuronal connectivity. In this study, we report on structure-kinetics relationships of a set of arylpiperazine-based 5-HT7R ligands. We found that it is not the overall lipophilicity of the molecule that influences drug-target interaction kinetics but rather the position of polar groups within the molecule. Next, we performed a combination of molecular docking studies and molecular dynamics simulations to gain insights into structure-kinetics relationships. These studies did not suggest specific contact patterns between the ligands and the receptor-binding site as determinants for compounds kinetics. Finally, we compared the abilities of two 5-HT7R agonists with similar receptor-binding affinities and different residence times to stimulate the 5-HT7R-mediated neurite outgrowth in mouse neuronal primary cultures and found that the compounds induced the effect with different timing. This study provides the first insights into the binding kinetics of arylpiperazine-based 5-HT7R ligands that can be helpful to design new 5-HT7R ligands with fine-tuning of the kinetic profile.
Progress in Neurobiology, 2021
To form and maintain extremely intricate and functional neural circuitry, mammalian neurons are t... more To form and maintain extremely intricate and functional neural circuitry, mammalian neurons are typically endowed with highly arborized dendrites and a long axon. The synapses that link neurons to neurons or to other cells are numerous and often too remote for the cell body to make and deliver new proteins to the right place in time. Moreover, synapses undergo continuous activity-dependent changes in their number and strength, establishing the basis of neural plasticity. The innate dilemma is then how a highly complex neuron provides new proteins for its cytoplasmic periphery and individual synapses to support synaptic plasticity. Here, we review a growing body of evidence that local protein synthesis in discrete sites of the axon and presynaptic terminals plays crucial roles in synaptic plasticity, and that deregulation of this local translation system is implicated in various pathologies of the nervous system.
Brain Research Bulletin, 2001
Tissue-type transglutaminases constitute a family of enzymes having a dual role. They catalyze th... more Tissue-type transglutaminases constitute a family of enzymes having a dual role. They catalyze the post-translational modification of proteins and play a role in signal transduction pathways, several isoforms have been cloned in the brain. Many in vitro experiments and post-mortem studies have claimed that the enzyme plays a central role in the development of neurodegenerative disorders, especially in CAG-triplet diseases. In the present investigation, we conducted an immunocytochemical study using two different antibodies raised against tissue-type transglutaminase. To confirm the enzyme expression, non-radioactive in situ hybridization was performed on adjacent sections. The study was completed by analyzing the ultrastructural localization of the enzyme by electron microscopy. Tissue-type transglutaminase was widely expressed in both the human and rat brain. Many positive cells exhibiting neuronal features were found in the brain and cerebellum. There was a preferential expression in elements of pyramidal and extrapyramidal pathways with less expression in the somatosensory system. The mRNA detection confirmed the distribution of the enzyme. The ultrastructural approach revealed the presence of the enzyme in all neuronal compartments. Light and electron microscopy studies showed the ubiquitous nature of the enzyme and its putative role in functional as well as putative pathological processes.
Calcium and Cellular Metabolism, 1997
International Journal of Molecular Sciences
The relatively few dopaminergic neurons in the mammalian brain are mostly located in the midbrain... more The relatively few dopaminergic neurons in the mammalian brain are mostly located in the midbrain and regulate many important neural functions, including motor integration, cognition, emotive behaviors and reward. Therefore, alteration of their function or degeneration leads to severe neurological and neuropsychiatric diseases. Unraveling the mechanisms of midbrain dopaminergic (mDA) phenotype induction and maturation and elucidating the role of the gene network involved in the development and maintenance of these neurons is of pivotal importance to rescue or substitute these cells in order to restore dopaminergic functions. Recently, in addition to morphogens and transcription factors, microRNAs have been identified as critical players to confer mDA identity. The elucidation of the gene network involved in mDA neuron development and function will be crucial to identify early changes of mDA neurons that occur in pre-symptomatic pathological conditions, such as Parkinson’s disease. I...
Advances in Behavioral Biology, 1985
Neurochemical Systems, 1985
Scientific Reports, 2015
Spine motility analysis has become the mainstay for investigating synaptic plasticity but is limi... more Spine motility analysis has become the mainstay for investigating synaptic plasticity but is limited in its versatility requiring complex, non automatized instrumentations. We describe an entropy-based method for determining the spatial distribution of dendritic spines that allows successful estimation of spine motility from still images. This method has the potential to extend the applicability of spine motility analysis to ex vivo preparations. Known since the time of Cajal, dendritic spines are an interesting subdomain present in most neurons, thought to play a role in synaptic plasticity and memory storage 1 . In fact, interrogation of spine density (number of spines per unit length) has become one of the most widely used contemporary morphological correlates of plasticity in neurobiology 2,3 . However, this approach contrasts with two-photon microscopy data demonstrating, in vivo, that synaptic plasticity may occur without modification of the total number of spines. Empirical data have now documented that it is the number of 'stable' spines over time rather than the total number of spines that is reliable in studying synaptic plasticity 4 . Therefore, methods that measure spine motility/turnover promise better insight into the physiology of dendritic spines 5 . Unfortunately, these methods require complex instrumentations and a technically demanding setup, which limit the possibility to extend their application to high throughput systems. This has resulted in a widespread failure to address spatial distribution of spines. Here, we introduce the notion that spatial distribution of spines along a dendrite can be represented as a bar code, carrying information about the local network, which, in turn, is related to the spine motility. We present a new method to indirectly assess changes in spine dynamics, based on measures of entropy from information theory, which takes into consideration the spatial distribution of the spines rather than their abundance. Entropy is a useful measure of the disorder and complexity in data series 6 , and similar quantities such as sample entropy, are better suited for short noisy time series 7 . It should be noted that the length of data series may, in fact, represent an important limitation when the aim is to calculate the amount of information (entropy) stored in the data; in the case of dendritic spines, the length of the data series is limited by the finite size of the dendrites and therefore their analysis require appropriate algorithms. Entropy (H) is a measure of the amount of information (classically measured in bits of information) required to describe a system. A sequence of random data shows high entropy, whereas a stream of very uniform, repetitive data shows low entropy (since less information is needed for their description).
Neuropharmacology, Jan 23, 2015
The 5-HT7 receptor (5-HT7R) mediates important physiological effects of serotonin, such as memory... more The 5-HT7 receptor (5-HT7R) mediates important physiological effects of serotonin, such as memory and emotion, and is emerging as a therapeutic target for the treatment of cognitive disorders and depression. Although previous studies have revealed an expression of 5-HT7R in cerebellum, particularly at Purkinje cells, its functional role and signaling mechanisms have never been described. Using patch-clamp recordings in cerebellar slices of adult mice, we investigated the effects of a selective 5-HT7R agonist, LP-211, on the main plastic site of the cerebellar cortex, the parallel fiber-Purkinje cell synapse. Here we show that 5-HT7R activation induces long-term depression of parallel fiber-Purkinje cell synapse via a postsynaptic mechanism that involves the PKC-MAPK signaling pathway. Moreover, a 5-HT7R antagonist abolished the expression of PF-LTD, produced by pairing parallel fiber stimulation with Purkinje cell depolarization; whereas, application of a 5-HT7R agonist impaired LTP...
The International Journal of Developmental Biology
The relatively few dopaminergic (DA) neurons in the mammalian brain regulate many important neura... more The relatively few dopaminergic (DA) neurons in the mammalian brain regulate many important neural functions, including motor integration, neuroendocrine hormone release, cognition, emotive behaviors and reward. A number of laboratories, including ours, have contributed to unravel the mechanisms of DA phenotype induction and maturation and elucidated the role of epigenetic factors involved in specification, development and maintenance of midbrain dopaminergic functions. DA progenitors are first "committed" to give rise to DA neurons by the action of two secreted factors, Sonic hedgehog and fibroblast growth factor 8 (FGF8). Subsequently, the function of selectively activated transcription factors, Nurr1 and Ptx3, is required for the DA final determination. Further development of DA neurotransmission requires specific interactions with the developing target striatal cells, which modulate key DA functions, namely synthesis and uptake of the neurotransmitter. Committed and de...
Most brain models focus on associative memory or calculation capability, experimentally inaccessi... more Most brain models focus on associative memory or calculation capability, experimentally inaccessible using physiological methods. Here we present a model explaining a basic feature of electroencephalograms (EEG). Our model is based on an electrical network with threshold firing and plasticity of synapses that reproduces very robustly the measured exponent 0.8 of the medical EEG spectra, a solid evidence for self-organized criticality. Our result are also valid on small-world lattices. We propose that an universal scaling behaviour characterizes many physiological signal spectra for brain controlled activities.
Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organot... more Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Moreover, experimental studies of morphology indicate that neurons develop a network of small-world-like connections, with the possibility of very high connectivity degree. Here we study a recent model based on self-organized criticality, which consists of an electrical network with threshold firing and activity-dependent synapse strengths. We study the model on a scale-free network, the Apollonian network, which presents many features of neuronal systems. The system exhibits a power law distributed avalanche activity. The analysis of the power spectra of the electrical signal reproduces very robustly the power law behaviour with the exponent 0.8, experimentally measured in electroencephalograms (EEG) spectra. The exponents are found to be quite stable with respect to initial configurations and strength of plastic remodelling, indicating that universality holds for a wide ...
Journal of neuroscience research, 1998
The presence and distribution of dystrophin was studied in selected areas of the chick embryo ner... more The presence and distribution of dystrophin was studied in selected areas of the chick embryo nervous system and in primary cultures. Dystrophin was examined at the protein level by immunocytochemistry and at the transcriptional level by a semiquantitative reverse transcriptase-polymerase chain reaction analysis. Immunofluorescence staining shows that dystrophin is present early during embryogenesis in dorsal root ganglia, spinal cord, and ciliary ganglia and colocalizes with neurofilament subunits. Cultured dorsal root ganglion, spinal cord, and ciliary ganglion neurons show immunoreactivity for dystrophin, both in cell bodies and along fibers. Dystrophin mRNA level in ciliary and dorsal root ganglia is higher than in spinal cord throughout development and shows a tissue-specific pattern of expression. In primary cultures of dorsal root ganglia and ciliary ganglia, dystrophin mRNA level increases with time in vitro. However, in spinal cord cultures, dystrophin mRNA drastically decr...
Neuroscience Letters, 2013
Brain serotonin (5-HT) systems modulate emotional, motivational and cognitive processes. Mutation... more Brain serotonin (5-HT) systems modulate emotional, motivational and cognitive processes. Mutations in the serotonin transporter (SERT) gene have been associated with susceptibility towards the development of several psychiatric disorders, both in humans and animal models. Present approach exploited a bilateral intra-hippocampus stereotaxic inoculation of lentiviruses, for enduring in vivo silencing of SERT. Control rats were bilaterally inoculated with heat-inactivated lentiviruses. These Lenti-SERT vectors were intended to eventually manipulate the neurotransmitter reuptake at synaptic level, thus enhancing tonic 5-HT transmission. We investigated whether such manipulation could induce behavioural alterations relevant to the modelling of ADHD, in particular symptoms of hyperactivity and impulsivity. Wistar rats were monitored for spontaneous home-cage locomotor activity and studied for impulsivity (Intolerance-to-Delay task). Results show that rats inoculated with Lenti-SERT vectors exhibited less pronounced circadian peaks of activity than controls. Moreover, Lenti-SERT compared to control rats exhibited a transient increase in choice for a delayed-larger reward over an immediate-small reward. This suggests that enhanced hippocampal serotonergic transmission produced a profile of restfulness and a decrease in cognitive impulsivity. This phenotype is consistent with available data both on 5-HT manipulations and hippocampal lesions. In conclusion, present findings may possibly disclose novel avenues towards the development of innovative therapeutical approaches for behavioural symptoms relevant to ADHD.
The International Journal of Neuropsychopharmacology, 2010
Dysfunction of brain dopamine transporter (DAT) has been associated with sensation seeking and im... more Dysfunction of brain dopamine transporter (DAT) has been associated with sensation seeking and impulse-control disorders. We recently generated a new animal model by stereotaxical inoculation of lentiviral vectors, which allowed localized intra-accumbal delivery of modulators for DAT gene : GFP (green fluorescent protein) control, silencers (Sil), a regulatable enhancer (DAT+), or both (DAT+Sil). Wistar male rats were followed both for socio-emotional profiles and for propensity to seek risky, uncertain rewards. Elevated anxiety and affiliation towards an unfamiliar partner emerged in Sil rats. Interestingly, in DAT+Sil rats (and Sil rats to a lesser extent) levels of playful social interaction were markedly reduced compared to controls. These DAT+Sil rats displayed a marked 'gambling-like' profile (i.e. preference for a large/uncertain over a small/sure reward), which disappeared upon doxycyclineinduced switch-off onto DAT enhancer, but consistently reappeared with doxycycline removal. MRIguided 1 H-MRS (at 4.7 T) examinations in vivo (under anaesthesia) revealed changes in the bioenergetic metabolites (phosphocreatine and total creatine) for DAT+Sil rats, indicating a functional up-regulation of dorsal striatum (Str) and conversely a down-regulation of ventral striatum (i.e. nucleus accumbens, NAc). A combined profile of (1) enhanced proneness to gambling and (2) strong social withdrawal is thus associated with altered DAT-induced balance within forebrain dopamine systems. In fact, risk of developing a gambling-prone, social-avoidant psychopathology might be associated with (1) dominant semiautomatic strategies and/or habits, developed within Str circuits, and (2) reduced NAc function, with poorer feedback adjustment on decisions by aversive experiences.
PLoS ONE, 2012
During neural development, spatially regulated expression of specific transcription factors is cr... more During neural development, spatially regulated expression of specific transcription factors is crucial for central nervous system (CNS) regionalization, generation of neural precursors (NPs) and subsequent differentiation of specific cell types within defined regions. A critical role in dopaminergic differentiation in the midbrain (MB) has been assigned to the transcription factor Nurr1. Nurr1 controls the expression of key genes involved in dopamine (DA) neurotransmission, e.g. tyrosine hydroxylase (TH) and the DA transporter (DAT), and promotes the dopaminergic phenotype in embryonic stem cells. We investigated whether cells derived from different areas of the mouse CNS could be directed to differentiate into dopaminergic neurons in vitro by forced expression of the transcription factor Nurr1. We show that Nurr1 overexpression can promote dopaminergic cell fate specification only in NPs obtained from E13.5 ganglionic eminence (GE) and MB, but not in NPs isolated from E13.5 cortex (CTX) and spinal cord (SC) or from the adult subventricular zone (SVZ). Confirming previous studies, we also show that Nurr1 overexpression can increase the generation of TH-positive neurons in mouse embryonic stem cells. These data show that Nurr1 ability to induce a dopaminergic phenotype becomes restricted during CNS development and is critically dependent on the region of NPs derivation. Our results suggest that the plasticity of NPs and their ability to activate a dopaminergic differentiation program in response to Nurr1 is regulated during early stages of neurogenesis, possibly through mechanisms controlling CNS regionalization.
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Papers by Carla Perrone-capano