Biology subjects

Aaltonen, A.

Publications and source records attributed to Aaltonen, A..

3 recordsLinked to original sources

bioRxiv2026

Altered striatal long-term potentiation in the eIF4E- TG ASD mouse model

Autism spectrum disorder (ASD) is associated with deficits in synaptic plasticity across brain regions. While striatal dysfunction is observed in various mouse models of ASD, the effect of ASD-associated genes on striatal plasticity has not been well characterised. We previously showed that overexpression of the SFARI ASD risk gene eIF4E in transgenic (eIF4E-TG) mice produces ASD-like behaviours and impairs dorsal striatal dopamine release. Here, we examined whether eIF4E overexpression alters striatal synaptic transmission and plasticity. Using microscopy, whole-cell electrophysiology, optogenetics and fast-scan cyclic voltammetry, we assessed dendritic morphology and excitatory synaptic properties of spiny projection neurons (SPNs). The eIF4E-TG mice exhibited higher dendritic spine density, elevated AMPA and NMDA receptor-mediated mEPSC frequency, and reduced AMPA mEPSC amplitude. We also observed an increased induction rate and magnitude of long-term potentiation (LTP) in SPNs, which is NMDA receptor-dependent but is not prevented by pharmacological D1 or D2 receptor antagonism under the conditions tested. Finally, we found that somatic and dendritic Ca2+ signals evoked by brief depolarisation are altered in SPNs from eIF4E-TG mice. Together, these findings are consistent with eIF4E overexpression promoting an NMDA receptor-dependent form of striatal LTP that is not prevented by D1/D2 receptor antagonism.

neuroscience↗

bioRxiv2025

Postnatal reduction of eIF4E overexpression in D1-SPNs ameliorates KCNQ dysfunction, hyperexcitability and ASD-like behaviours.

An imbalance between the direct and indirect pathways of the striatum has been implicated in the pathophysiology of ASD, which corresponds with an increase in repetitive behaviours and hyperactivity. The ASD risk gene EIF4E promotes translation, and its overexpression in mice increases repetitive behaviours and hyperactivity. We used the eIF4E-transgenic mouse model of ASD to study cell-type specific disruptions in the direct and indirect pathways using fibre photometry, electrophysiology, conditional gene silencing, and behavioural analysis. We found that direct pathway SPNs activity increased during exploratory behaviour and identified D1-SPN hyperexcitability and reduced KCNQ channel function in striatal slices. Reduction of eIF4E specifically in the D1-SPNs of adult mice normalised KCNQ function, D1-SPN hyperexcitability and ameliorated repetitive and hyperactive behaviours. Our results highlight the critical role of eIF4E in ASD-associated motor behaviours, elucidate cell-specific mechanisms driving hyperactivity and provide new insight into potential therapeutic targets for ASD and other neurodevelopmental disorders. Overall, this study underscores the translational potential of modulating protein synthesis pathways to address core motor symptoms in ASD.

neuroscience↗

bioRxiv2024

Dysregulated acetylcholine-mediated dopamine neurotransmission in the eIF4E Tg mouse model of autism spectrum disorders.

Autism Spectrum Disorders (ASD) consist of diverse neurodevelopmental conditions where core behavioral symptoms are critical for diagnosis. Altered dopamine neurotransmission in the striatum has been suggested to contribute to the behavioral features of ASD. Here, we examine dopamine neurotransmission in a mouse model of ASD characterized by elevated expression of the eukaryotic initiation factor 4E (eIF4E), a key regulator of cap-dependent translation, using a comprehensive approach that encompasses genetics, behavior, synaptic physiology, and imaging. The results indicate that increased eIF4E expression leads to behavioral inflexibility and impaired striatal dopamine release. The loss of normal dopamine neurotransmission is due to a defective nicotinic receptor signaling that regulates calcium dynamics in dopaminergic axons. These findings reveal an intricate interplay between eIF4E, DA neurotransmission, and behavioral flexibility, provide a mechanistic understanding of ASD symptoms and offer a foundation for targeted therapeutic interventions.

neuroscience↗