Sodium current and sodium channel intramembrane gating charge movement (Q) were monitored in voltage-clamped frog node of Ranvier after modification of all sodium channels by batrachotoxin (BTX). BTX caused an approximately threefold increase in steepness of the Q vs. voltage relationship and a 50-mV negative shift in its midpoint. The maximum amount of intramembrane charge was virtually identi...

Programmed cell death is a prominent feature of neural development that is regulated by a variety of cell-cell interactions. We used the avian ciliary ganglion to dissect the relative contributions of target tissues vs. ganglionic inputs in regulating cell death. The two populations of the ciliary ganglion innervate different targets: choroid neurons innervate vasculature, whereas ciliary neuro...

BACKGROUND Botulinum toxin A (BTX) is the currently preferred symptomatic treatment for primary hemifacial spasm (HFS), but its long-term efficacy and safety are not known. OBJECTIVE To assess the long-term effectiveness and safety of BTX in the treatment of primary HFS. DESIGN Retrospective review of medical records of the 1st and 10th years of treatment. SETTING Outpatient clinics of 4 ...

Vocal fold injection with botulinum toxin type A (BTX-A) may be used as an adjunct treatment for habit cough in children. We conducted a retrospective review of 3 cases involving children aged 11 to 13 years with habit cough treated with vocal fold injection of BTX-A. Injections of BTX-A to the thyroarytenoid muscles were effective in breaking the cough cycle in all 3 children. Their coughs rec...

BACKGROUND It has been suggested that intrasphincteric injection of botulinum toxin (BTX) may represent an alternative therapy to balloon dilatation in achalasia. The aim of the present study was to test the effectiveness of botulinum toxin injections in achalasia patients, as assessed using lower oesophageal sphincter pressure (LOSP) and symptom scores, and to compare the response in patients ...

The voltage-gated sodium channel is the site of action of more than six classes of neurotoxins and drugs that alter its function by interaction with distinct, allosterically coupled receptor sites. Batrachotoxin (BTX) is a steroidal alkaloid that binds to neurotoxin receptor site 2 and causes persistent activation. BTX binding is inhibited allosterically by local anesthetics. We have investigat...

Many poisonous organisms carry small-molecule toxins that alter voltage-gated sodium channel (NaV) function. Among these, batrachotoxin (BTX) from Pitohui poison birds and Phyllobates frogs stands out because of its lethality unusual effects on NaV How these toxin-bearing avoid autointoxication remains poorly understood. In frogs, a DIVS6 pore-forming helix N-to-T mutation has been proposed as ...

This is a concise review of the uses of botulinum toxins (BTXs) in dermatology and cosmetic procedures. It is a clinical rather than a basic science, pharmacological review. BTX had been initially used for selectively reducing and balancing periorbital muscle activity; thereby, reducing childhood strabismus and blepharospasm. This clinical research was initiated by Dr. Alan Scott over 40 years ...

Botulinum toxin (BTX) is widely used in different areas of medicine. Its major and most obvious effect consists in the block of acetylcholine-mediated nerve-to-muscle signaling transmission determining the unique efficacy of BTX used for treatment of neurological disorders related to muscle hypertonicity and spasticity. BTX-induced transient relaxation of the facial muscles used for elimination...

OBJECTIVE To assess the effect on freezing of gait (FOG) of botulinum toxin type A (BTX-A) injections in advanced Parkinson's disease (PD) patients. METHOD BTX-A 150 IU or normal saline was injected into each leg's calf muscles by a blinded investigator. FOG severity was assessed at set intervals (6-month follow-up). RESULTS Eleven age- and disease severity-matched PD patients with disablin...