scholarly journals p75 Neurotrophin Receptor Regulates the Timing of the Maturation of Cortical Parvalbumin Cell Connectivity and Promotes Ocular Dominance Plasticity in Adult Visual Cortex

2018 ◽  
Author(s):  
Elie Baho ◽  
Bidisha Chattopadhyaya ◽  
Marisol Lavertu-Jolin ◽  
Raffaele Mazziotti ◽  
Patricia N Awad ◽  
...  

SummaryBy virtue of their extensive axonal arborisation and perisomatic synaptic targeting, cortical inhibitory Parvalbumin (PV) cells strongly regulate principal cell output and plasticity. An interesting aspect of PV cell connectivity is its prolonged maturation time course, which is completed only by end of adolescence. The p75 neurotrophin receptor (p75NTR) regulates a wide range of cellular function, including apoptosis, neuronal process remodeling and synaptic plasticity, however its role on cortical circuit development is still not well understood, mainly because localizing p75NTR expression with cellular and temporal resolution has, so far, been challenging.Using RNAscope and a modified version of the Proximity Ligation Assay (PLA), we show that p75NTR mRNA and protein are expressed in cortical PV cells in the postnatal and adult brain. Further, p75NTR expression in PV cells decreases between postnatal day (P)14 and P26, at a time when PV cell synapse numbers increase dramatically. Conditional knockout of p75NTR in single PV neurons in cortical organotypic cultures and in PV cell networks in vivo leads to precocious formation of PV cell perisomatic innervation and perineural nets around PV cell somata, suggesting that p75NTR expression controls the timing of the maturation of PV cell connectivity in the adolescent cortex.Remarkably, we found that p75NTR is still expressed, albeit at low level, in PV cells in adult cortex. Interestingly, activation of p75NTR onto PV cells in adult visual cortex in vivo is sufficient to destabilize their connectivity and to reintroduce juvenile-like cortical plasticity following monocular deprivation. Altogether, our results show that p75NTR activation dynamically regulates PV cell connectivity, and represents a novel tool to foster brain plasticity in adults.

2018 ◽  
Author(s):  
Anna Steinzeig ◽  
Cecilia Cannarozzo ◽  
Eero Castren

Heightened neuronal plasticity expressed during early postnatal life has been thought to permanently decline once critical periods have ended. For example, monocular deprivation is able to shift ocular dominance in the mouse visual cortex during the first months of life, but this effect is lost later in life. However, various treatments such as the antidepressant fluoxetine can reactivate a critical period-like plasticity in the adult brain. When monocular deprivation is supplemented with chronic fluoxetine administration, a major shift in ocular dominance is produced after the critical period has ended. In the current study, we characterized the temporal patterns of fluoxetine-induced plasticity in the adult mouse visual cortex, using in vivo optical imaging. We found that artificially-induced plasticity in ocular dominance extended beyond the duration of the naturally occurring critical period, and continued as long as fluoxetine was administered. However, this fluoxetine-induced plasticity period ended as soon as the drug was not given. Taken together, our data highlights how a combination of pharmacological treatment and environmental change could be used to improve strategies in antidepressant therapy in humans.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ettore Tiraboschi ◽  
Ramon Guirado ◽  
Dario Greco ◽  
Petri Auvinen ◽  
Jose Fernando Maya-Vetencourt ◽  
...  

The nervous system is highly sensitive to experience during early postnatal life, but this phase of heightened plasticity decreases with age. Recent studies have demonstrated that developmental-like plasticity can be reactivated in the visual cortex of adult animals through environmental or pharmacological manipulations. These findings provide a unique opportunity to study the cellular and molecular mechanisms of adult plasticity. Here we used the monocular deprivation paradigm to investigate large-scale gene expression patterns underlying the reinstatement of plasticity produced by fluoxetine in the adult rat visual cortex. We found changes, confirmed with RT-PCRs, in gene expression in different biological themes, such as chromatin structure remodelling, transcription factors, molecules involved in synaptic plasticity, extracellular matrix, and excitatory and inhibitory neurotransmission. Our findings reveal a key role for several molecules such as the metalloproteases Mmp2 and Mmp9 or the glycoprotein Reelin and open up new insights into the mechanisms underlying the reopening of the critical periods in the adult brain.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
José Fernando Maya-Vetencourt ◽  
Laura Baroncelli ◽  
Alessandro Viegi ◽  
Ettore Tiraboschi ◽  
Eero Castren ◽  
...  

The central nervous system architecture is markedly modified by sensory experience during early life, but a decline of plasticity occurs with age. Recent studies have challenged this dogma providing evidence that both pharmacological treatments and paradigms based on the manipulation of environmental stimulation levels can be successfully employed as strategies for enhancing plasticity in the adult nervous system. Insulin-like growth factor 1 (IGF-1) is a peptide implicated in prenatal and postnatal phases of brain development such as neurogenesis, neuronal differentiation, synaptogenesis, and experience-dependent plasticity. Here, using the visual system as a paradigmatic model, we report that IGF-1 reactivates neural plasticity in the adult brain. Exogenous administration of IGF-1 in the adult visual cortex, indeed, restores the susceptibility of cortical neurons to monocular deprivation and promotes the recovery of normal visual functions in adult amblyopic animals. These effects were accompanied by a marked reduction of intracortical GABA levels. Moreover, we show that a transitory increase of IGF-1 expression is associated to the plasticity reinstatement induced by environmental enrichment (EE) and that blocking IGF-1 action by means of the IGF-1 receptor antagonist JB1 prevents EE effects on plasticity processes.


2009 ◽  
Vol 29 (34) ◽  
pp. 10627-10637 ◽  
Author(s):  
J. K. Knowles ◽  
J. Rajadas ◽  
T.-V. V. Nguyen ◽  
T. Yang ◽  
M. C. LeMieux ◽  
...  

10.1038/11158 ◽  
1999 ◽  
Vol 2 (8) ◽  
pp. 699-705 ◽  
Author(s):  
Christine Brennan ◽  
Kimberly Rivas-Plata ◽  
Story C. Landis

2015 ◽  
Vol 112 (41) ◽  
pp. 12852-12857 ◽  
Author(s):  
Michael S. Sidorov ◽  
Eitan S. Kaplan ◽  
Emily K. Osterweil ◽  
Lothar Lindemann ◽  
Mark F. Bear

A feature of early postnatal neocortical development is a transient peak in signaling via metabotropic glutamate receptor 5 (mGluR5). In visual cortex, this change coincides with increased sensitivity of excitatory synapses to monocular deprivation (MD). However, loss of visual responsiveness after MD occurs via mechanisms revealed by the study of long-term depression (LTD) of synaptic transmission, which in layer 4 is induced by acute activation of NMDA receptors (NMDARs) rather than mGluR5. Here we report that chronic postnatal down-regulation of mGluR5 signaling produces coordinated impairments in both NMDAR-dependent LTD in vitro and ocular dominance plasticity in vivo. The data suggest that ongoing mGluR5 signaling during a critical period of postnatal development establishes the biochemical conditions that are permissive for activity-dependent sculpting of excitatory synapses via the mechanism of NMDAR-dependent LTD.


2020 ◽  
Author(s):  
Angelina Lesnikova ◽  
Plinio Cabrera Casarotto ◽  
Senem Merve Fred ◽  
Mikko Voipio ◽  
Frederike Winkel ◽  
...  

AbstractPerineuronal nets (PNNs) are an extracellular matrix structure rich in chondroitin sulphate proteoglycans (CSPGs) which preferentially encase parvalbumin-containing (PV+) interneurons. PNNs restrict cortical network plasticity but the molecular mechanisms involved are unclear. We found that reactivation of ocular dominance plasticity in the adult visual cortex induced by chondroitinase (chABC)-mediated PNN removal requires intact signaling by the neurotrophin receptor TRKB in PV+ neurons. Additionally, we demonstrate that chABC increases TRKB phosphorylation (pTRKB), while PNN component aggrecan attenuates BDNF-induced pTRKB in cortical neurons in culture. We further found that protein tyrosine phosphatase sigma (PTPσ, PTPRS), receptor for CSPGs, interacts with TRKB and restricts TRKB phosphorylation. PTPσ deletion increases phosphorylation of TRKB in vitro and in vivo in male and female mice, and juvenile-like plasticity is retained in the visual cortex of adult PTPσ deficient mice (PTPσ+/-). The antidepressant drug fluoxetine, which is known to promote TRKB phosphorylation and reopen critical period-like plasticity in the adult brain, disrupts the interaction between TRKB and PTPσ by binding to the transmembrane domain of TRKB. We propose that both chABC and fluoxetine reopen critical period-like plasticity in the adult visual cortex by promoting TRKB signaling in PV+ neurons through inhibition of TRKB dephosphorylation by the PTPσ-CSPG complex.Significance statementCritical period-like plasticity can be reactivated in the adult visual cortex through disruption of perineuronal nets (PNNs) by chondroitinase treatment, or by chronic antidepressant treatment. We now show that the effects of both chondroitinase and fluoxetine are mediated by the neurotrophin receptor TRKB in parvalbumin-containing (PV+) interneurons. We found that chondroitinase-induced visual cortical plasticity is dependent on TRKB in PV+ neurons. Protein tyrosine phosphatase type S (PTPσ, PTPRS), a receptor for PNNs, interacts with TRKB and inhibits its phosphorylation, and chondroitinase treatment or deletion of PTPσ increases TRKB phosphorylation. Antidepressant fluoxetine disrupts the interaction between TRKB and PTPσ, thereby increasing TRKB phosphorylation. Thus, juvenile-like plasticity induced by both chondroitinase and antidepressant treatment is mediated by TRKB activation in PV+ interneurons.


2020 ◽  
Author(s):  
Monique S. Mendes ◽  
Jason Atlas ◽  
Zachary Brehm ◽  
Antonio Ladron-de-Guevara ◽  
Matthew N. McCall ◽  
...  

AbstractMicroglia are the resident immune cells in the brain with the capacity to autonomously self-renew. Under basal conditions, microglial self-renewal appears to be slow and stochastic, although microglia have the ability to proliferate very rapidly following depletion or in response to injury. Because microglial self-renewal has largely been studied using static tools, the mechanisms and kinetics by which microglia renew and acquire mature characteristics in the adult brain are not well understood. Using chronic in vivo two-photon imaging in awake mice and PLX5622 (Colony stimulating factor 1 receptor (CSF1R) inhibitor) to deplete microglia, we set out to understand the dynamic self-organization and maturation of microglia following depletion in the visual cortex. We confirm that under basal conditions, cortical microglia show limited turnover and migration. Following depletion, however, microglial repopulation is remarkably rapid and is sustained by the dynamic division of the remaining microglia in a manner that is largely independent of signaling through the P2Y12 receptor. Mathematical modeling of microglial division demonstrates that the observed division rates can account for the rapid repopulation observed in vivo. Additionally, newly-born microglia resemble mature microglia, in terms of their morphology, dynamics and ability to respond to injury, within days of repopulation. Our work suggests that microglia rapidly self-renew locally, without the involvement of a special progenitor cell, and that newly born microglia do not recapitulate a slow developmental maturation but instead quickly take on mature roles in the nervous system.Graphical Abstract(a) Microglial dynamics during control condition. Cartoon depiction of the heterogenous microglia in the visual cortex equally spaced. (b) During the early stages of repopulation, microglia are irregularly spaced and sparse. (c) During the later stages of repopulation, the number of microglia and the spatial distribution return to baseline. (d-f) We then created and ran a mathematical model that sampled the number of microglia, (d) the persistent doublets, (e) the rapid divisions of microglia and (f) the secondary divisions of microglia during the peak of repopulation day 2-day 3. The mathematical model suggested that residual microglia can account for the rapid repopulation we observed in vivo.


2021 ◽  
Author(s):  
Sara Cadoni ◽  
Charlie Demene ◽  
Matthieu Provansal ◽  
Diep Nguyen ◽  
Dasha Nelidova ◽  
...  

Remote, precisely controlled activation of the brain is a fundamental challenge in the development of brain machine interfaces providing feasible rehabilitation strategies for neurological disorders. Low-frequency ultrasound stimulation can be used to modulate neuronal activity deep in the brain, but this approach lacks spatial resolution and cellular selectivity and loads the brain with high levels of acoustic energy. The combination of the expression of ultrasound-sensitive proteins with ultrasound stimulation (sonogenetic stimulation) can provide cellular selectivity and higher sensitivity, but such strategies have been subject to severe limitations in terms of spatiotemporal resolution in vivo, precluding their use for real-life applications. We used the expression of large-conductance mechanosensitive ion channels (MscL) with high-frequency ultrasonic stimulation for a duration of milliseconds to activate neurons selectively at a relatively high spatiotemporal resolution in the rat retina ex vivo and the primary visual cortex of rodents in vivo. This spatiotemporal resolution was achieved at low energy levels associated with negligible tissue heating and far below those leading to complications in ultrasound neuromodulation. We showed, in an associative learning test, that sonogenetic stimulation of the visual cortex generated light perception. Our findings demonstrate that sonogenetic stimulation is compatible with millisecond pattern presentation for visual restoration at the cortical level. They represent a step towards the precise transfer of information over large distances to the cortical and subcortical regions of the brain via an approach less invasive than that associated with current brain machine interfaces and with a wide range of applications in neurological disorders.


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