Immunoreactivity of Glutamic Acid Decarboxylase (GAD) Isoforms in the Central Nervous System of the Barn Spider, Araneus cavaticus

Abstract

The γ‐aminobutyric acid (GABA) has long been considered as an inhibitory neurotransmitter in the central nervous system (CNS) of both vertebrates and arthropods. Since the glutamic acid decarboxylase (GAD) has a restricted tissue distribution and catalyzes the conversion of L‐glutamate to GABA, immunoreactivity of GAD isoforms can reveal distribution of GABAergic neurons in the CNS. In the CNS of the spider Araneus cavaticus, immunoreactivity of GAD isoforms can be detected in the optic lobes including neurons and neuropiles of the supraesophageal ganglia. Strong GAD‐like immunoreactive cell bodies are concentrated in two bilaterally symmetric cell clusters of the protocerebrum. Some intrinsic cell bodies near the central body also show strong immunoreactivity. However, the intrinsic nerve masses and some of the longitudinal and transverse tracts within the supraesophageal ganglion are only lightly labelled, and the fibers transverse the hemisphere and the central fibrous masses are not labelled. Among the three basic types of cell bodies surrounding the central body, several clusters of the Type‐C cells show strong GAD‐like immunoreactivity, however both of the Type‐A and Type‐B cells are not labelled at all.

Effects of sevoflurane anesthesia on righting reflex and hemolymph gas analysis variables for Chilean rose tarantulas (Grammostola rosea)

“…25,26 Interestingly, modulation of GABA receptors is believed to be a substantial component of the mechanism of action of volatile anesthetics. 27 This may occur in spiders; results of a recent study 28 indicate GABAergic neurons are detected in multiple areas of the CNS of barn spiders (Araneus cavaticus). During recovery from sevoflurane anesthesia, most of the drug is likely removed from a spider' s body by means of diffusion through the book lungs.…”

Fine Structure of Cardiac Sarcomeres in the Black Widow Spider Latrodectus mactans

“…Female specimens were anesthetized with CO 2 and dissected under light microscope in a drop of spider Ringer's solution consisting of 160 mM NaCl, 7.5 mM KCl, 4 mM CaCl 2 , 1 mM MgCl 2 , 4 mM NaHCO 3 , 20 mM glucose, pH 7.4 (Moon & Tillinghast 2013;Kim et al 2016). The heart was gently removed and fixed in a mixture of 2% paraformaldehyde and 2.5% glutaraldehyde buffered with caccodylate buffer.…”

Fine structural reconstruction on the testicular cyst of the furrow orb weaver,Larinioides cornutusby 3D volume rendering

“…The opisthosoma of the specimens was dissected in spider ringer solution (128 mM NaCl, 18 mM CaCl 2 , 1.3 mM KCl, and 2.3 mM NaHCO 3 , pH 7.4) in a way to remove exoskeleton and isolate testis. (Moon & Tillinghast 2013;Park & Moon 2014) For light microscopic observation, the opisthosomae were fixed in Bouin's fixative solution for 24 hours, and dehydrated using ascending concentration of graded series of ethanol. After dehydration, ethanol was substituted to xylene for clearing.…”