Add like
Add dislike
Add to saved papers

Enhanced long-term potentiation-like plasticity of the trigeminal blink reflex circuit in blepharospasm.

Journal of Neuroscience 2006 January 12
Benign essential blepharospasm (BEB) is a focal cranial dystonia affecting eye closure. Here, we tested the hypothesis that BEB is associated with abnormal plasticity of the neuronal circuits mediating reflex blinks. In patients with BEB and healthy age-matched controls, we used the conditioning protocol introduced by Mao and Evinger (2001) to induce long-term potentiation (LTP)-like plasticity in trigeminal wide dynamic range neurons of the blink reflex circuit. High-frequency trains of electrical stimuli were repeatedly given over the right supraorbital nerve (SO) and timed to coincide with the R2 response elicited by a preceding SO stimulus. High-frequency stimulation (HFS) resulted in a long-lasting and input-specific potentiation of the R2 response in both groups, yet the facilitation of the R2 response was markedly increased in patients relative to controls. Botulinum toxin (BTX) injections in both orbicularis oculi muscles normalized the previously enhanced LTP-like plasticity of the R2 response. The increased responsiveness to HFS provides first-time evidence that LTP-like plasticity is increased in the trigeminal reflex circuit of patients affected by BEB. The results also show that the enhanced modifiability is not fixed in BEB, because BTX injections can transiently restore normal LTP-like plasticity. We propose that an abnormal corneal input induced by excessive blinking exacerbates increased LTP-like plasticity in BEB. BTX treatment removes the latter and restores plasticity toward normal values. Our results support the concept that maladaptive reorganization contributes to the pathophysiology of focal dystonias.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app