Translation of BDNF-gene transcripts with short 3′ UTR in hippocampal CA1 neurons improves memory formation and enhances synaptic plasticity-relevant signaling pathways

- BDNF transcripts with short 3′ UTR in the CA1 improves fear, object location memory.
- Overexpressed BDNF improves relearning of object location, but not object shape.
- Expression enhances persistently synaptic plasticity relevant signaling pathways.
- Higher dose BDNF expression does not improve long-term passive avoidance memory.
- Higher dose of BDNF expression mediates fearful behavior and seizures.

While the brain-derived neurotrophic factor (BDNF) gene and its multiple transcripts have been recognized as a key factor for learning, but the specific involvement of BDNF translated from BDNF transcripts with short-3′ untranslated region (short 3′ UTR) in learning and memory requires further analysis. In this paper, we present data to show that the transduction of hippocampal CA1 neurons with AAV9-5′ UTR-BDNF (short 3′ UTR)-IRES-ZsGreen and the subsequent expression of BDNF enhanced the phosphorylation of synaptic plasticity relevant proteins and improved passive avoidance and object location, but not object recognition memory. In addition, BDNF improved the relearning of object location. At higher BDNF overexpression levels, the fear behavior was accompanied with a decline in the passive avoidance memory 24 h post training, and with an enhanced fear conditioning performance. In addition, these animals developed spontaneous seizures. Thus, the expression of BDNF in the hippocampal CA1 region has the potential to improve fear and object location memory in wild type mouse strains when the region and expression levels of BDNF are well controlled.