Search results for "Autonomic Fibers"
showing 8 items of 8 documents
A muscarinic inhibition of the noradrenaline release evoked by postganglionic sympathetic nerve stimulation
1969
1. The noradrenaline output from isolated rabbit hearts perfused with Tyrode solution was estimated fluorimetrically. The postganglionic sympathetic nerves of the heart were stimulated (10 shocks/sec; 1 msec) for three 1 min periods with intervals of 10 min. 2. The noradrenaline output evoked by 3 consecutive stimulation periods decreased exponentially. 3. Acetylcholine (10−9–10−6 g/ml) administered continuously one min before to one min after the second stimulation caused a dose-dependent reduction of the noradrenaline output evoked by the second stimulation to as low as 19% of the normal value. Acetylcholine in the concentrations applied did not cause a noradrenaline output by itself. 4. …
Inhibition by parasympathetic nerve stimulation of the release of the adrenergic transmitter
1970
Isolated rabbit atria were perfused with Tyrode solution containing (+)-amphetamine. Electrical stimulation of the right postganglionic sympathetic fibres caused an output of noradrenaline which was significantly decreased by simultaneous stimulation of the vagus nerves.
Intermittent Horner's syndrome on alternate sides: a hint for locating spinal lesions.
1980
A patient with a cervical intramedullary ependymoma is described who exhibited a Horner's syndrome on alternate sides. Pharmacological study demonstrated damage to the pre-ganglionic sympathetic neurons. Disregarding cases with the Shy-Drager syndrome, three comparable case reports have been found in the literature where the fluctuating expression of Horner's syndrome, alternating from one side to the other, was attributable to a lesion of the cervical spinal cord. In contrast to the present patient, the pharmacological responses of these patients indicated a lesion of the central sympathetic pathway.
Nitric oxide synthase neurons in the rodent spinal cord: distribution, relation to Substance P fibers, and effects of dorsal rhizotomy.
2001
The indirect immunofluorescent method was employed to investigate the distribution of neuronal nitric oxide synthase-like immunoreactivity(nNOS-LI) in the spinal cord of the golden hamster and to compare it to data obtained from rats. Immunoreactive neurons were found throughout the cervico-sacral extent in the dorsal horn (mainly in laminae I-III) and in the preganglionic autonomic regions, i.e., the sympathetic intermediolateral nucleus (IML), lateral funicle (LF), intercalated region (IC), the area surrounding the central canal (CA), and the sacral preganglionic parasympathetic cell group. While the distribution of immunoreactive cells was generally similar in both species, some differen…
Calcitonin gene-related peptide-like immunoreactivity in spinal cord and superior cervical ganglion of the djungarian hamster (Phodopus sungorus)
1993
The indirect immunofluorescent method was employed to investigate the distribution of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the spinal cord and superior cervical ganglion of the Djungarian hamster Phodopus sungorus. In cross-sections of the spinal cord, immunoreactive fibres and terminals were found in laminae 1 and 2 in high density, in the dorsolateral (Lissauer's) tract, in ventral and lateral horns, and in the area surrounding the central canal. A few CGRP-LI perikarya were seen in the ventral but not the dorsal horn. CGRP-LI was further observed in preganglionic sympathetic neurons which were labelled by retrograde axonal transport of fluoro-gold (FG) follo…
A presynaptic excitatory M1 muscarine receptor at postganglionic cardiac noradrenergic nerve fibres that is activated by endogenous acetylcholine.
1990
Rabbit atria were isolated with the extrinsic right vagus and sympathetic nerves intact and perfused with Tyrode solution. Noradrenaline overflow evoked by sympathetic nerve stimulation (SNS) at 3 Hz for 3 min was determined before, during, and after vagus nerve stimulation (VNS), also at 3 Hz and for 3 min. The VNS pulses preceded the SNS pulses by 3, 100 and 233 ms. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline. Pirenzepine 80 nmol/l failed to alter the muscarinic inhibition of noradrenaline overflow when the vago-sympathetic impulse intervals were 3 and 233 ms. At an interval of 100 ms VNS did not significantly inhibit noradrenaline ove…
Evidence for bilateral vagal innervation of postganglionic parasympathetic neurons in chicken heart
1983
Stimulation of the cervical vagus nerves caused an output of acetylcholine (ACh) from the isolated chicken heart, which almost exclusively was released from the postganglionic neurons: (+)-tubocurarine (3 X 10(-14) M) reduced the output to 12 +/- 6% (n = 7) of the control. Stimulation of the two nerve trunks ws equally effective in releasing ACh.--Evidence that a large number of postganglionic neurons receives bilateral innervation was based on two experimental series. (1). The sum of the ACh outputs evoked by unilateral (separate) nerve stimulation of the right and the left vagus was higher than the bilaterally evoked output (100%) and increased with increasing frequencies (10, 20 and 40 H…
The effects of the tricyclic antidepressants desipramine, doxepin and iprindole on the isolated perfused rabbit heart.
1974
1. The right sympathetic nerves of isolated perfused rabbit hearts were stimulated electrically (1 msec, supramaximal strength, 15 sec) with increasing frequencies (0.25–20 Hz) at 3 min intervals before and 20 min after starting perfusion with desipramine, doxepin or iprindole. Ventricular rate, right atrial and right ventricular tensions were recorded using the transverse method. 2. Sympathic nerve stimulation caused ventricular arrhythmias in the presence of desipramine (3.3 and 5.0 · 10−6 M) and doxepin (1.6−4.7×10−6 M) but failed to produce arrhythmias in hearts not exposed to drugs, or after iprindole, cocaine and atropine. 3. When desipramine or doxepin was added to Tyrode solution co…