Pimozide Inhibits Type II but Not Type I Hair Cells in Chicken Embryo and Adult Mouse Vestibular Organs
Roberta Giunta1, Giulia Cheli1, Giorgio Rispoli2
1Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy.
Biomedicines
|January 8, 2025
Summary
Pimozide, an antipsychotic, affects vestibular hair cells by altering ion channel currents. This drug impacts type II hair cells more than type I, potentially explaining dizziness and offering new treatment avenues for vestibular disorders.
Area of Science:
- Neuroscience
- Pharmacology
- Otolaryngology
Background:
- Pimozide is a conventional antipsychotic used for schizophrenia, Tourette's syndrome, and other conditions.
- It blocks D2 receptors and ion channels, with known side effects including dizziness and imbalance.
- Vestibular hair cells (type I and II) are crucial for balance and may be affected by Pimozide.
Purpose of the Study:
- To investigate the effects of Pimozide on ionic currents in vestibular hair cells.
- To compare the effects on type I and type II hair cells across different species (chicken and mouse).
Main Methods:
- Whole-cell patch-clamp technique was employed.
- Ionic currents (IK,V, IK,1, Ih) in chicken embryo and adult mouse vestibular hair cells were measured.
- Pimozide's effects on type I and type II hair cells were analyzed.
Main Results:
- Pimozide increased the outward rectifying K+ current (IK,V) in type II hair cells of both chicken embryos and adult mice.
- Pimozide decreased the inward rectifying K+ current (IK,1) and the mixed Na+/K+ current (Ih) in type II hair cells.
- Type I hair cells showed minimal response in chicken embryos, but a slight increase in IK,V in adult mice.
Conclusions:
- Pimozide's actions on ion channels in vestibular hair cells may explain its side effects like dizziness.
- The drug's inhibitory effects on mammalian hair cells could be relevant for treating vestibular disorders such as Ménière's disease.
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