bioRxiv Science⌕ Search

Biology subjects

Andreyanov, M.

Publications and source records attributed to Andreyanov, M..

2 recordsLinked to original sources

Epigenetic inheritance of complex learning abilities in the mammalian brain

For several decades, the question of whether cognitive and learning capacities can be inherited through non-genetic mechanisms has been the subject of ongoing debate. Here, we provide the first evidence of transgenerational inheritance of enhanced ability to learn complex tasks in the mammalian rodent brain. These inherited learning enhancements are not limited to specific stimuli, sensory modalities, or learning paradigms. Using behavioral, cellular biophysical, methylomics, genetics and molecular methods, we find that the inherited epigenetic modifications reflect an enhanced neuronal learning state, driven by increased intrinsic neuronal excitability in most pyramidal neurons in the relevant neuronal networks. This enhancement is mediated by persistent downregulation of the muscarinic M-current and is associated with widespread changes in DNA methylation, notably within coding genes associated with the M-current, the Kv7 pathway, in the hippocampi of trained F0 rats, as well as in non-coding RNAs in their sperm samples. Remarkably, a significant portion of these DNA methylation changes were also observed in the hippocampi of their untrained F1 offspring. These findings suggest that complex learning abilities can be inherited in the mammalian brain, as the offspring of trained rodents are born with the biophysical modifications that enable them to become super-learners, the exact change that occurs in their parents brains only after the rule learning.

neuroscience↗

A novel polycistronic method tailored for engineering split GECIs

We assessed the feasibility of using stop-codons as means to obtain polycistronic expression in eukaryotic cells. We show robust bicistronic expression of different open reading frames (ORFs), when these are cloned in-sequence and simply separated by stop codons (in-or out-of-frame), in heterologous expression systems and primary neurons. We further find this method to support polycistronic expression of three stop-codon-separated ORFs in vivo, which guided us to develop a technicolor Genetically-Encoded Functional Rainbow Indicators (GEFRIs) for monitoring cellular morphology and neuronal firing, concomitantly. These findings guided us to develop a new technique we denote SPLIT--Stop-codon mediated Polycistronic Induction in HeTerologous expression systems-- for rapid and easy development of fragmented proteins by the sole use of stop codons. We validated the SPLIT method by generating several new split-GFP variants, then engineer a palette of functional split-GCaMP6s variants and, lastly, generate a split ca2+-probe localized at ER and mitochondria junctions, denoted split-MEGIC. With the use of the probe, we show presence and activity of mito-ER contact sites within individual dendritic spines. Split-MEGIC can thereby be imaged by two-photon excitation in vivo in mice brains and, by standard confocal microscope in transgenic zebrafish larvae. Together, we explore non-canonical translation mechanisms and show these to be highly pervasive in various cell types in vitro and in vivo. We harness translation re-initiation to express multiple ORFs, to engineer rainbow indicators and to swiftly produce functional split-proteins and probes.

neuroscience↗