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 ...

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 and northwestern South C ...

''), 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