Joro spider toxin (joro toxin, JSTX) – a toxin which was originally extracted from the

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

of the joro spider (''

Trichonephila clavata ''Trichonephila clavata'', also known as the , is a member of the ''Trichonephila'' genus. The spider can be found throughout Japan (except Hokkaidō), Korea, Taiwan, China, and since 2020, much of northeastern Georgia (U.S.), Georgia and north ...

''), originally native to Japan.

Biochemical analysis

Joro toxin has demonstrated the ability to selectively block * postsynaptic

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

potentials and * AMPA glutamate receptors. It inhibits *

NMDA receptor The ''N''-methyl-D-aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA rece ...

s in the CNS of vertebrates. Joro toxin does not affect * aspartate-induced neural depolarization, * resting membrane potential, * nerve terminal spontaneous signalling, or * inhibitory

postsynaptic potential Postsynaptic potentials are changes in the membrane potential of the postsynaptic terminal of a chemical synapse. Postsynaptic potentials are graded potentials, and should not be confused with action potentials although their function is to ini ...

Sources

* * *

References

{{reflist, 22em, refs= {{cite journal , first1=Nobufumi , last1=Kawai , first2=Akiko , last2=Niwa , first3=Takashi , last3=Abe , year=1982 , title=Spider venom contains specific receptor blocker of glutaminergic synapses , journal=Brain Research , volume=247 , pages=169–171 , pmid=6127145 , issue=1 , doi=10.1016/0006-8993(82)91044-7 , s2cid=38772662 {{cite journal , first1=Koichi , last1=Shudo , first2=Yasuyuki , last2=Endo , first3=Yuichi , last3=Hashimoto , first4=Yoshio , last4=Aramaki , first5=Terumi , last5=Nakajima , first6=Nobufumi , last6=Kawai , year=1987 , title=Newly synthesized analogues of the spider toxin block the crustacean glutamate receptor , journal=Neuroscience Research , volume=5 , pages=82–85 , issue=1 , pmid=2829068 , doi=10.1016/0168-0102(87)90026-5 , s2cid=41151994 {{cite journal , last=Kawai , first=Nobufumi , year=1991 , title=Spider toxin and pertussis toxin differentiate post- and presynaptic glutamate receptors , journal=Neuroscience Research , volume=12 , pages=3–12 , issue=1 , pmid=1660989 , doi=10.1016/0168-0102(91)90095-G , s2cid=23524210 {{cite journal , first1=Alan L. , last1=Mueller , first2=Benedict C. , last2=Albensi , first3=Alan H. , last3=Ganong , first4=Linda S. , last4=Reynolds , first5=Hunter , last5=Jackson , year=1991 , title=Arylamine spider toxins antagonize NMDA receptor-mediated synaptic transmission in rat hippocampal slices , journal=Synapse , volume=9 , issue=4 , pages=244–250 , pmid=1662833 , doi=10.1002/syn.890090403 , s2cid=2546161 Spider toxins