Antidromic

It was generally assumed that it cannot and this became known as Dale s Law. During his studies on antidromic vasodilation he wrote (1935) When we are dealing with two different endings of the same sensory neuron, the one peripheral and concerned with vasodilation and the other at a central synapse, can we suppose that the discovery and identification of a chemical transmitter at axon reflex dilation would furnish a hint as to the nature of the transmission process at a central synapse. The possibility has at least some value as a stimulus to further experiments . 

Figure 2.13 Relation between the action potential recorded intracellularly from a cat spinal motoneuron following antidromic stimulation (int.) and the local field potential recorded with an extracellular electrode (ext.). (Adapted from Terzuolo, AC and Araki, T (1961) Ann. NY Acad. Sci. 94 547-558). Published by NYAS...

The effect of amphetamine on these neostriatal neurons was relatively uniform. Four doses of amphetamine were tested 0.25, 1.0, 2.5, and 5.0 mg/kg, SC. At all four doses, amphetamine reduced the firing rate of both antidromic and nonantidromic neurons during the initial drug-induced period of locomotion as compared to the rate during predrug locomotion (figure 1). 

FIGURE 1. Change in firing rate of both antidromically and... 

ANSWER I think it is very clear that there is a population of autoreceptors at the axonal end, but there is no population of autoreceptors in the axon that passes through the medial forebrain level. The antidromic stimulation is up there, and it looks as if amphetamine and related dopamine agonists cause a decrease in excitability of the terminal field in the same way that they cause a decrease in excitability in the cell body. 

The water molecules form polymeric chains which include homodromic and antidromic six-membered hydrogen-bonded circles each one of the water species is either threefold or fourfold coordinated, donating at least one H-bond to the surface of a neighboring bilayer. 

Wang, R. Y. 8r Aghajanian, G. K. (1977). Antidromically identified serotoninergic neurons in the rat midbrain raphe evidence for collateral inhibition. Brain Res. 132, 186-93. 

Kainate (200 nM) renders the mossy-fiber axons more excitable, as evidenced by an increase in the presynaptic fiber volley as well as lowered threshold for antidromic action potentials. At the same time, a kainate-induced suppression of synaptic transmission and depression of presynaptic calcium influx was observed (92). In contrast, application of very low concentrations of kainate (50 nM) facilitates synaptic transmission at the mossy fibers (77,100). The kainate-induced facilitation is blocked by LY382884, suggesting a role for GLUK5-containing receptors (77). However, only depression of transmission has been observed with ATPA (35). Thus, the facilitatory and depressory effects of kainate could be mediated by different receptor populations that have distinct pharmacological properties. 

Antidromic stimulation of sensory nerves produces vasodilatation and increased blood flow in the skin [57, 58] that is blocked by histamine receptor antagonists [59] or by pretreatment with compound 48/80 [60],... 

SP antagonists have been shown to inhibit the vasodilatation and plasma extravasation induced by antidromic stimulation of the saphenous nerves or by the infusion of SP [64]. In these experiments somatostatin also inhibited the effect due to antidromic stimulation but not that induced by infusion of SP. Interestingly, the opiate agonist, [DMet2-Pro5]enkephalinamide, also inhibited the vasodilatation evoked by antidromic nerve stimulation but not that induced by SP infusion [64],... 

Figure 4.1. Model of neurogenic inflammation. Stimulation at the skin initiates orthodromic impulses in sensory nerve receptors which elicit antidromic impulses in branching collaterals. The release of neuropeptides such as calcitonin gene-related peptide (CGRP), substance P (SP), and somatostatin (SOM) from nerve terminals ensues and they in turn stimulate the release of histamine (H) and the generation of leukotrienes (LT) from nearby mast cells. These mediators then produce vasodilatation and an increase in vascular permeability. In addition, they act on the nerve terminal to produce further...

Anticholinesterase agents of all classes can initiate antidromic firing of action potentials in motor neurons, possibly due to an activation of prejunctional ACh receptors that are activated by the elevated synaptic ACh. Quaternary ammonium inhibitors can also act as agonists at these receptors. The initiation of antidromic firing may be a mechanism by which cholinesterase inhibitors produce fasciculation of skeletal muscle. 

Holton, P. The liberation of ATP on antidromic stimulation of sensory nerves, J. Physiol. (Lond) 1959, 145, 494-504. 

Dendrobine at a dose of 3 X 10-5 M reduced the dorsal root potential and reflex. It provoked a mild hyperpolarization in both dorsal and ventral roots of frog isolated spinal cord. It affected the (3-alanine- and taurine-induced depolarization of primary afferent terminals and reversibly blocked the presynaptic inhibition caused by antidromic conditioning stimulation of the ventral root potential induced by repetitive antidromic stimulation of ventral root and lowered maximum. It would be interesting to learn whether further research of the Dendrobium species discloses any alkaloid interfering with the glycinergic system, an aspect discussed under the following heading. 

Rat Skin and peritoneal mast cells histamine release induced by antidromic electrical stimulation or SP perfusion... 

Sawyer SF, Tepper JM, Young SJ, Groves PM. Antidromic activation of dorsal raphe neurons from neostriatum physiological characterization and effects of terminal autoreceptor activation. Brain Res 1985 332 15-28. 

In the cyclic systems, more commonly observed in the cyclodextrin hydrates, all three alternatives, 1, 2, 3, are expanded to correspond to the configurations 5, 6, and 7, for which the descriptors homodromic, 5, antidromic, 6, and heterodromic, 7, have been applied3 [109], which can also be used for the description of linear... 

It is important to note that water molecules in hydrates do not necessarily interrupt cooperativity, as in the antidromic cyclic system 6, if they are at the intersection of chains, as in 10,... 

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