Neurotrophin 4 Infusion for Laryngeal Nerve Regeneration in an Aged Rat

Begin with an anesthetized aged rat, immobilized in a reclined position.

Aging leads to laryngeal muscle denervation and a reduction in neuromuscular junctions—where nerves connect to muscle.

Extend the tongue and insert a plastic speculum to keep the mouth open.

Take an endoscope integrated with a syringe prefilled with neurotrophin-4 (NTF4), a nerve growth factor.

Under dark conditions, turn on the endoscope’s light source.

Initiate video recording and immerse the endoscope tip in warm water to prevent condensation, ensuring a clear field of view.

Using endoscopic guidance, position the needle near the left vocal fold.

As the vocal folds open during inspiration, insert the needle into the left thyroarytenoid muscle, an intrinsic laryngeal muscle.

Deliver the NTF4, then withdraw the needle. Allow the rat to recover.

NTF4 stimulates laryngeal nerve regeneration, which promotes neuromuscular junction formation. This highlights the neurotherapeutic potential of NTF4.

30 minutes before the injection, warm aseptically prepared 50-microliter doses of the neurotrophin or saline in a 25-degree Celsius water bath. When the treatments are ready, recline an anesthetized rat in the supine position on