scholarly journals Decrease of glutamate decarboxylase (GAD)-immunoreactive nerve terminals in the substantia nigra after kainic acid lesion of the striatum.

1981 ◽  
Vol 29 (8) ◽  
pp. 977-980 ◽  
Author(s):  
W H Oertel ◽  
D E Schmechel ◽  
M J Brownstein ◽  
M L Tappaz ◽  
D H Ransom ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Substantia Nigra ◽  
Kainic Acid ◽  
Glutamate Decarboxylase ◽  
Marked Reduction ◽  
Immunohistochemical Localization ◽  
Nerve Terminals ◽  
Immunohistochemical Examination ◽  
Axon Terminals ◽  
Gad Activity

Antiserum sheep 3 against rat brain glutamate decarboxylase (GAD) was employed for the immunohistochemical localization of GAD-immunoreactive nerve terminals in the substantia nigra (SN). To test whether the antiserum specifically localized GAD-containing axon terminals, the effect of kainic acid-induced striatal lesions on the reactive nerve endings in the SN was investigated. Seven days after the injection of 1 microgram kainic acid into the striatum, a 65% decrease in GAD-enzyme activity occurred in the ipsilateral SN. On immunohistochemical examination there was correspondingly a marked reduction of GAD-positive terminals. The parallel decrease in biochemical and immunohistochemical GAD activity indicates that antiserum sheep 3 can be used as a specific immunohistochemical probed for GAD-containing elements.

scholarly journals Decrease of Glutamate Decarboxylase Activity in Substantia Nigra and Caudoputamen following Transient Hyperglycemic Ischemia in the Rat

1989 ◽  
Vol 9 (6) ◽  
pp. 897-901 ◽  
Author(s):  
Jaroslava Folbergrová ◽  
Maj-Lis Smith ◽  
Kenji Inamura ◽  
Bo K. Siesjö
Keyword(s):  
Cerebral Cortex ◽  
Substantia Nigra ◽  
Glutamate Decarboxylase ◽  
Cell Damage ◽  
Decarboxylase Activity ◽  
Transient Ischemia ◽  
Inhibitory Transmission ◽  
Generalized Seizures ◽  
Postischemic Period ◽  
Gad Activity

Glutamate decarboxylase (GAD) activity was determined in caudoputamen (CP), substantia nigra (SN), and cerebral cortex (CCX) after 19–22 h of recirculation following 10 min of transient ischemia in hyperglycemic rats, i.e., under the conditions when previously a pronounced nerve cell damage was demonstrated in both CP and SN. The present results demonstrate a decrease of GAD activity in SN by 30% and in CP by 22% and no change in CCX. No statistically significant change in GAD activity could be detected in SN, CP, or CCX 1,4, and 7 days following 10 min of ischemia in normoglycemic animals. The decrease of GAD activity in SN at the time preceding the onset of postischemic seizures suggests that there may be an imbalance between augmented excitatory and decreased inhibitory transmission in SN. We tentatively conclude that this may increase the probability of generalized seizures in the postischemic period following ischemia in hyperglycemic animals.

Enzymatic condensation of dopamine and acetaldehyde: a salsolinol synthase from rat brain

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Xuechai Chen ◽  
Abida Arshad ◽  
Hong Qing ◽  
Rui Wang ◽  
Jianqing Lu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Substantia Nigra ◽  
Human Subjects ◽  
Enzymatic Reaction ◽  
Brain Regions ◽  
Activity Detection ◽  
Reaction Products ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Salsolinol Synthase

AbstractSalsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline; Sal) is structurally similar to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which is supposed to have a role in the development of Parkinson-like syndrome in both human and non-human subjects. In the human brain, the amount of (R)-enantiomer of Sal is much higher than (S)-enantiomer, suggesting that a putative enzyme may participate in the synthesis of (R)-salsolinol, called (R)-salsolinol synthase. In this study, the (R)-salsolinol synthase activity in the condensation of dopamine and acetaldehyde was investigated in the crude extracts from the brains of Sprague Dawley rats. Identification of the enzymatic reaction products and enzyme activity detection were achieved by HPLC-electrochemical detection. The discovery of this enzyme activity in rat’s brain indicates the natural existence of (R)-salsolinol synthase in the brains of humans and rats, and it is distributed in most brain regions of rat with higher activity in soluble proteins extracted from striatum and substantia nigra.

scholarly journals Acetylcholinesterase from the motor nerve terminal accumulates on the synaptic basal lamina of the myofiber.

1991 ◽  
Vol 115 (3) ◽  
pp. 755-764 ◽  
Author(s):  
L Anglister
Keyword(s):  
Basal Lamina ◽  
Ache Activity ◽  
Neuromuscular Junctions ◽  
Motor Nerve ◽  
Synaptic Cleft ◽  
Motor Nerve Terminal ◽  
Nerve Terminals ◽  
Axon Terminals ◽  
Muscle Nerve ◽  
Almost All

Acetylcholinesterase (AChE) in skeletal muscle is concentrated at neuromuscular junctions, where it is found in the synaptic cleft between muscle and nerve, associated with the synaptic portion of the myofiber basal lamina. This raises the question of whether the synaptic enzyme is produced by muscle, nerve, or both. Studies on denervated and regenerating muscles have shown that myofibers can produce synaptic AChE, and that the motor nerve may play an indirect role, inducing myofibers to produce synaptic AChE. The aim of this study was to determine whether some of the AChE which is known to be made and transported by the motor nerve contributes directly to AChE in the synaptic cleft. Frog muscles were surgically damaged in a way that caused degeneration and permanent removal of all myofibers from their basal lamina sheaths. Concomitantly, AChE activity was irreversibly blocked. Motor axons remained intact, and their terminals persisted at almost all the synaptic sites on the basal lamina in the absence of myofibers. 1 mo after the operation, the innervated sheaths were stained for AChE activity. Despite the absence of myofibers, new AChE appeared in an arborized pattern, characteristic of neuromuscular junctions, and its reaction product was concentrated adjacent to the nerve terminals, obscuring synaptic basal lamina. AChE activity did not appear in the absence of nerve terminals. We concluded therefore, that the newly formed AChE at the synaptic sites had been produced by the persisting axon terminals, indicating that the motor nerve is capable of producing some of the synaptic AChE at neuromuscular junctions. The newly formed AChE remained adherent to basal lamina sheaths after degeneration of the terminals, and was solubilized by collagenase, indicating that the AChE provided by nerve had become incorporated into the basal lamina as at normal neuromuscular junctions.

The fate of foreign endplates in cross-innervated rat soleus muscle

1980 ◽  
Vol 208 (1171) ◽  
pp. 189-222 ◽  
Keyword(s):  
Muscle Fibre ◽  
Proximal Region ◽  
Presynaptic Terminal ◽  
Motor Axon ◽  
Muscle Fibres ◽  
Nerve Terminals ◽  
Axon Terminals ◽  
Adult Rat ◽  
Rat Soleus Muscle ◽  
Postsynaptic Site

After transplantation of the superficial fibular and the medial plantar nerve to neighbouring sites in the proximal region of adult rat soleus muscles many muscle fibres were initially innervated by axons in both foreign nerves after resection of the original soleus nerve. The foreign endplates were formed at ectopic sites and were often separately locatedon individual muscle fibres. After 3-4 weeks many endplates had been eliminated and most muscle fibres were innervated by only a single foreign axon. Many muscle fibres still had multiple esterase-staining endplate sites in the region innervated by the foreign nerve. On exami­nation by electronmicroscopy, some of these sites were seen to have lost their presynaptic terminal while the postsynaptic structure of the endplate remained intact. Other sites were only partially occupied by motor axon terminals. On each muscle fibre there was always at least one fully occupied endplate region. In some instances separate endplate sites on the same muscle fibre were innervated by branches of the same motor axon. We conclude that the elimination of endplates is due to a competitive interaction between motor axons innervating the same muscle fibre. Morphologically, the elimination of functional endplates is caused by a retraction of nerve terminals from the postsynaptic site.

Kainic Acid-Stimulated Release of Taurine from the Rat Substantia Nigra in Vivo

1997 ◽  
pp. 949-953
Author(s):  
L. Bianchi ◽  
R. Zamfirova ◽  
M. Nerini ◽  
J. P. ◽  
L. Delia Corte
Keyword(s):  
Substantia Nigra ◽  
Kainic Acid ◽  
Rat Substantia Nigra

Kainic acid lesions increase reafferentation of the striatum by substantia nigra grafts

1993 ◽  
Vol 621 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Hidetoshi Takashima ◽  
Benjamin R. Walker ◽  
H. Eleanor Cannon-Spoor ◽  
William J. Freed
Keyword(s):  
Substantia Nigra ◽  
Kainic Acid
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