INTRODUCTION: Previous studies indicate that the 5-HT7 receptor may play a crucial role in the modulation of neuroplasticity. Activation of this receptor has been shown to rescue hippocampal long-term potentiation (LTP) in brain slices obtained from rodent models of nervous system disorders and to influence neuronal cytoarchitecture under physiological conditions. Moreover, mice lacking the 5-HT7 receptor exhibit impaired hippocampal LTP and deficits in contextual learning. Given that earlier studies indicate higher expression of the 5-HT7 receptor during early postnatal development, we examined brain slices obtained from both adult and juvenile mice.

AIM(S): We investigated the effects of 5-HT7 receptor activation on synaptic plasticity in hippocampal slices obtained from healthy adult (8-12 weeks old) and juvenile (13-15 postnatal days) mice.

METHOD(S): Extracellular recordings of field excitatory postsynaptic potentials (fEPSPs) were performed in the CA1 region. The 5-HT7 receptor was activated by bath application of the selective agonist LP-211. LTP was induced using theta-burst stimulation (TBS). In addition, paired-pulse stimulation was applied to assess short-term synaptic plasticity.

RESULTS: In contrast to previous reports suggesting a role in plasticity modulation, activation of the 5-HT7 receptor did not affect either long-term or short-term synaptic plasticity in the CA1 region of adult mice. Similarly, no significant differences were observed between control slices and those treated with LP-211 in juvenile mice.

CONCLUSIONS: These findings suggest that activation of the 5-HT7 receptor does not modulate synaptic plasticity in the CA1 region of either adult or juvenile mice under physiological conditions. It is possible that the functional role of the 5-HT7 receptor becomes more important under pathological conditions.

FINANCIAL SUPPORT: Nr rejestracyjny: 2019/35/D/NZ4/02042; Kierownik projektu: dr Monika Bijata