Characterization of Neuronal RNA Modifications during Non-associative Learning in Aplysia Reveals Key Roles for tRNAs...

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Post-transcriptional RNA modifications are increasingly recognized as key regulators of neural plasticity and protein synthesis.
• Studying these modifications during learning is challenging due to complex models and limited untargeted profiling methods for small samples.

Purpose of the Study:

• To investigate spatiotemporal changes in neuronal RNA modifications during learning in *Aplysia californica*.
• To identify specific RNA modifications that covary with behavioral sensitization.

Main Methods:

• Utilized mass spectrometry for untargeted profiling of numerous RNA modifications in *Aplysia californica* ganglia.
• Analyzed RNA modification patterns in trained versus naive animals undergoing behavioral sensitization.

Main Results:

• Observed distinct RNA modification patterns in the ganglia of trained and naive *Aplysia*.
• Identified significantly elevated levels of two transfer RNA (tRNA) modifications, 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) and 1-methyladenosine (m1A), in trained subjects.
• Demonstrated a correlation between tRNA modifications, increased polyglutamine synthesis, and neuronal excitability.

Conclusions:

• Established the first link between noncoding RNA modifications and non-associative learning.
• These findings highlight the role of specific tRNA modifications in neuronal plasticity and memory formation.