What question did this study set out to answer?

This research aims to explore how depression affects BDNF release from platelets and the role of TrkB receptors.

April 1, 2026Open Access

Platelet BDNF release by antidepressants is decreased in a rat model of depression: implication of platelet TrkB expression change

Q: What is the clinical evidence from this study?

Study design: Other. Population: Depression (rat model) (n=21). Intervention: Antidepressants (sertraline, milnacipran, paroxetine, fluvoxamine) vs. Control rats (vehicle). Primary outcome: Platelet BDNF release in response to antidepressants (p=<0.05).

Key Result

Antidepressant-induced BDNF release from platelets was reduced by 15% to 43% in a rat model of depression compared to controls, associated with increased platelet TrkB expression.

Key Points

This research aims to explore how depression affects BDNF release from platelets and the role of TrkB receptors.
Induced depression in rats using corticosterone injections (20 mg/kg) for 21 days.
Prepared washed platelet samples from the rats to measure BDNF release.
Evaluated changes in TrkB expression in platelets under depressive states.
Platelet BDNF release decreased by 15-43% in depressed rats treated with various antidepressants.
Release reductions were inhibited by the TrkB antagonist K252a.
Full-length and truncated TrkB isoforms showed increased expression in depressed rats.

Structured PICO

Population

21 Male Wistar rats, aged 10 weeks, weighing 300-350g; 10 depressed rats prepared by repeated subcutaneous corticosterone injections (20 mg/kg) for 21 consecutive days and 11 vehicle-treated control rats.

Intervention

In vitro exposure of washed platelets to antidepressants (sertraline, milnacipran, paroxetine, fluvoxamine) and TrkB inhibitor K252a for 60 minutes.

Comparator

Washed platelets from vehicle-treated control rats.

Outcome

Platelet BDNF release and TrkB expression (full-length and truncated).surrogate

In a rat model of depression, decreased platelet BDNF release in response to antidepressants and increased TrkB expression suggest altered peripheral BDNF-TrkB modulation.

Main Result

p-value: p=<0.05

Limitations

The source of platelet BDNF remains obscure
It is unclear why both full-length and truncated TrkB receptors increased in platelets
Findings are from an animal model and require clinical studies in patients with major depressive disorders

Abstract

Objective: The aim of this study was to investigate the mechanism of brain-derived neurotrophic factor (BDNF) release from platelets in a rat model of depression focusing on the BDNF receptor, tyrosine kinase receptor B (TrkB). Several recent studies have suggested that serum levels of BDNF are decreased in depression, and this decrease is thought to reflect BDNF levels in the brain.Because the source of serum BDNF is considered to be the platelets, we have confirmed that antidepressants release BDNF from platelets. However, the effect of depression itself on BDNF release is unknown.Methods: We prepared depressed rats by repeated injections of corticosterone (20 mg/kg) for 21 consecutive days. We used washed platelet samples prepared from rats, measured platelet BDNF release in response to antidepressants, and evaluated the change of TrkB expression in platelets in depressive states.Results: BDNF release from platelets was reduced by sertraline (15%), milnacipran (15%), paroxetine (37%), and fl uvoxamine (43%) in depression model rats compared with controls. This release was suppressed by K252a, a TrkB inhibitor. Moreover, platelet expression of both full-length and truncated TrkB isoforms were increased in depressed rats.Conclusions: Decreased platelet BDNF release induced by antidepressants explains the decreased serum BDNF concentration seen in depression, and changes in TrkB expression might alter BDNF release from platelets. We suggest that in depression BDNF-TrkB modulation in platelets is associated with peripheral BDNF changes.

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Cite This Study

Kimihiko et al. (Fri,) conducted a other in Depression (rat model) (n=21). Antidepressants (sertraline, milnacipran, paroxetine, fluvoxamine) vs. Control rats (vehicle) was evaluated on Platelet BDNF release in response to antidepressants (p=<0.05). Antidepressant-induced BDNF release from platelets was reduced by 15% to 43% in a rat model of depression compared to controls, associated with increased platelet TrkB expression.

synapsesocial.com/papers/69cd7aa45652765b073a7ef6 https://doi.org/https://doi.org/10.15114/smj.85s.1

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