Biology subjects

Maroto, I. B.

Publications and source records attributed to Maroto, I. B..

3 recordsLinked to original sources

bioRxiv2025

Astrocytic PI3Kα controls synaptic plasticity and cognitive function via serine metabolism

Astrocytes are known to modulate neuronal activity by gliotransmission and through metabolic regulation. However, the connection between these two processes is still poorly defined. In this work we show that the p110 isoform of the phosphatidylinositol 3-kinase (PI3K) in astrocytes is required for long-term potentiation (LTP) and has an impact on learning and memory. Using a specific deletion of p110 from hippocampal astrocytes in adult mice, we found that LTP depends on astrocytic p110 to sustain D-serine levels for the activation of NMDA receptors during LTP induction. This requirement is based on the L-serine biosynthetic pathway of the astrocyte, which is defective in the absence of p110 because of a reduced glycolytic flux. Accordingly, the behavioral impairment in mice lacking p110 can be rescued by in vivo administration of L-serine. These results link for the first time the function of PI3K in astrocytes to cerebral metabolism and its influence in synaptic plasticity and cognition.

neuroscience↗

bioRxiv2023

The CB1 receptor interacts with cereblon and drives cereblon deficiency-associated memory shortfalls

Cereblon/CRBN is a substrate-recognition component of the Cullin4A-DDB1-Roc1 E3 ubiquitin ligase complex. Destabilizing mutations in the human CRBN gene cause a form of autosomal recessive non-syndromic intellectual disability (ARNSID) that is modelled by knocking-out the mouse Crbn gene. A reduction in excitatory neurotransmission has been proposed as an underlying mechanism of the disease, but the intimate factors eliciting this impairment remain mostly unknown. Here we report that CRBN molecules selectively located on glutamatergic neurons are necessary for proper memory function. Combining various in vivo approaches, we show that the cannabinoid CB1 receptor (CB1R), a key suppressor of synaptic transmission, is overactivated in CRBN deficiency-linked ARNSID mouse models, and that the memory deficits observed in these animals can be rescued by acute CB1R-selective pharmacological antagonism. Molecular studies demonstrated that CRBN interacts physically with CB1R and impairs the CB1R-Gi/o-cAMP-PKA pathway in a ubiquitin ligase-independent manner. Taken together, these findings unveil that CB1R overactivation is a driving mechanism of CRBN deficiency-linked ARNSID and anticipate that the blockade of CB1R could constitute a new therapy for this orphan disease.

neuroscience↗

bioRxiv2020

IGF-1 facilitates extinction of conditioned fear

Insulin-like growth factor-1 (IGF-1) plays a key role in synaptic plasticity, degenerative diseases, spatial learning, and anxiety-like behavioral processes. While IGF-1 regulates neuronal activity in many areas of the brain, its effect on synaptic plasticity and animal behavior dependent on the prefrontal cortex remain unexplored. Here, we show that IGF-1 induces a long-lasting depression of the medium and slow post-spike afterhyperpolarization (mAHP and sAHP), increasing the excitability of layer 5 pyramidal neurons of the infralimbic cortex. Besides, IGF-1 mediates a long-term depression of both inhibitory and excitatory synaptic transmission that results in a longterm potentiation of the postsynaptic potentials. We demonstrate that these synaptic and intrinsic regulatory processes mediated by IGF-1 favor the fear extinction memory. These results show novel functional consequences of IGF-1 signaling on animal behavior tasks dependent on the prefrontal cortex, revealing IGF-1 as a key element in the control of the fear extinction memory. Impact StatementIGF-1 modulates the neuronal firing and synaptic plasticity in infralimbic cortex, favoring the extinction memory

neuroscience↗