The postnatal ontogeny of [t25I]a-bungarotoxin (a-Btx) binding distribution in rat neocortex was described and quantified using autoradiography of in vitro labeled brain sections. During the first two weeks, distinctive transitory radial and laminar patterns emerged. Dense columnar bands of a-Btx binding extended through the depth of primary sensory cortex, including somatosensory, visual and a...

BACKGROUND Botulinum toxin type B (BTX-B; Myobloc) has recently been introduced for the treatment of dynamic rhytides. This serotype is structurally similar to botulinum toxin type A (BTX-A; Botox) and appears to produce equivalent muscular paralysis. Because of the fact that some patients may become resistant to the effects of BTX-A with its continued use or may require large doses of type A t...

BACKGROUND Hyperhidrosis is a chronic disease characterized by increased sweat production. Local injections of botulinum toxin A (BTX-A) have been extensively used for treatment of primary hyperhidrosis (idiopathic). The current treatment for this condition involves several intradermal injections, resulting in poor patient compliance due to injection-related pain. Therefore, new protocols, incl...

Botulinum neurotoxins (BTXs) inhibit the presynaptic release of acetylcoline causing a chemical denervation that results in sustained muscle weakness and have been used in the past 20 years to induce selective blocking of hyperactive striatal (and smooth) muscles. All the different seven serotypes of BTXs have in common the mechanism of action (block of the neuroexocytosis machinery inside the ...

Botulinum neurotoxins (BTXs) inhibit the presynaptic release of acetylcoline causing a chemical denervation that results in sustained muscle weakness and have been used in the past 20 years to induce selective blocking of hyperactive striatal (and smooth) muscles. All the different seven serotypes of BTXs have in common the mechanism of action (block of the neuroexocytosis machinery inside the ...

Batrachotoxin (BTX)-modified Na+ currents were characterized in GH3 cells with a reversed Na+ gradient under whole-cell voltage clamp conditions. BTX shifts the threshold of Na+ channel activation by approximately 40 mV in the hyperpolarizing direction and nearly eliminates the declining phase of Na+ currents at all voltages, suggesting that Na+ channel inactivation is removed. Paradoxically, t...

Background The objective of this study was to evaluate the influence of masticatory muscle injection of botulinum toxin type A (BTX-A) on the growth of the mandibular bone in vivo. Methods Eleven Sprague-Dawley rats were used, and BTX-A (n = 6) or saline (n = 5) was injected at 13 days of age. All injections were given to the right masseter muscle, and the BTX-A dose was 0.5 units. All of the...

α-Bungarotoxin (α-Btx) binds to the five agonist binding sites on the homopentameric α7-acetylcholine receptor, yet the number of bound α-Btx molecules required to prevent agonist-induced channel opening remains unknown. To determine the stoichiometry for α-Btx blockade, we generate receptors comprised of wild-type and α-Btx-resistant subunits, tag one of the subunit types with conductance muta...

AIM To test antinociceptive properties of botulinum toxin type A (BTX-A) in rats with carrageenan- and capsaicin-induced pain and inflammation. METHODS Pain was provoked with carrageenan (1%) or capsaicin (0.1%) injection into the plantar surface of the rat paw-pad. The effect of BTX-A 5 U/kg on carrageenan- and capsaicin-induced mechanical and thermal hypersensitivity, as well as the size of...

The effects of batrachotoxin (BTX) on the membrane potential and conductances of squid giant axons have been studied by means of intracellular microelectrode recording, internal perfusion, and voltage clamp techniques. BTX (550-1100 nM) caused a marked and irreversible depolarization of the nerve membrane, the membrane potential being eventually reversed in polarity by as much as 15 mv. The dep...