-
British Journal of Anaesthesia Oct 1980The ability of gallamine, metocurine, pancuronium, tubocurarine and atropine to block the response to postganglionic stimulation of the vagus nerve were measured in...
The ability of gallamine, metocurine, pancuronium, tubocurarine and atropine to block the response to postganglionic stimulation of the vagus nerve were measured in isolated, spontaneously beating guineapig atria. From analysis of the results in conjunction with those of earlier assays of concentrations that block effects of preganglionic vagal stimulation, it was concluded that only tubocurarine possessed ganglionic blocking activity. From calculation of the extent of block of muscarinic receptors at drug concentrations which blocked the response to postganglionic vagal stimulation, it was concluded that gallamine and pancuronium have an antivagal action exerted most probably on the postganglionic nerve terminal, and that this action is the most likely explanation of the tachycardia seen clinically with these two drugs.
Topics: Animals; Atropine; Autonomic Fibers, Postganglionic; Depression, Chemical; Dose-Response Relationship, Drug; Electric Stimulation; Female; Guinea Pigs; Heart; Heart Atria; Hexamethonium Compounds; In Vitro Techniques; Male; Neuromuscular Blocking Agents; Vagus Nerve
PubMed: 7437219
DOI: 10.1093/bja/52.10.981 -
Spine Apr 2007We investigated changes in spinal somatosensory-evoked potential (SSEP) and nerve action potential (NAP), correlated behavior, and associated pathologic observation in... (Comparative Study)
Comparative Study
STUDY DESIGN
We investigated changes in spinal somatosensory-evoked potential (SSEP) and nerve action potential (NAP), correlated behavior, and associated pathologic observation in experimental radiculopathy.
OBJECTIVES
To create a rat model of sacrococcygeal radiculopathy for determining the validity of SSEP and NAP.
SUMMARY OF BACKGROUND DATA
We examined the diagnostic sensitivity and value of electrophysiologic tests for evaluating lumbosacral root disease conflict. An appropriate animal model can help verify the value of these tests.
METHODS
Preganglionic lesion group rats were given 2 loose ligatures around the cauda equina at the sacrum, and postganglionic lesion group rats were given 2 loose ligatures on the conjunction of the sacrococcygeal nerve roots and the caudalis nerve after they had received a laminectomy. Control group rats received a sham operation. SSEPs and NAPs were recorded preligature and postligature, and 3 times after surgery. These electrophysiologic observations were compared and correlated with tail-flick reflex and histology.
RESULTS
All experimental group rats developed thermal hyperalgesia on day 14, as indicated by a significant reduction in TFL (tail-flick latency), which continued for 3 months. Amplitude decreased significantly and latency increased significantly in all SSEP recordings immediately after the operation; these changes persisted for 3 months. There were no significant differences between the experimental groups, but there were significant differences between the control and experimental groups. NAP amplitude and latency from the caudalis nerves did not change in any group in the first 2 postoperative weeks. From the second postoperative week until the 3-month follow-up, amplitude was significantly decreased and latency prolonged in the postganglionic group but unchanged in the others.
CONCLUSIONS
Both SSEP and NAP are useful for evaluating electrophysiologic changes after various radiculopathies. The data also suggest that the conductivity of the peripheral nerve (NAP) was affected by the postganglionic compression of the corresponding nerve root, but not by the preganglionic lesion.
Topics: Action Potentials; Animals; Autonomic Fibers, Postganglionic; Autonomic Fibers, Preganglionic; Disease Models, Animal; Electrophysiology; Evoked Potentials, Somatosensory; Hyperalgesia; Radiculopathy; Rats; Rats, Sprague-Dawley; Sacrococcygeal Region; Tail
PubMed: 17450068
DOI: 10.1097/01.brs.0000261030.97483.ac -
Brain Research Mar 1999In the paracervical ganglion (PCG) of the rat, double-labelling immunofluorescence for catecholamine-synthesizing enzymes and HPLC measurement of catecholamine contents...
Small intensely fluorescent cells of the rat paracervical ganglion synthesize adrenaline, receive afferent innervation from postganglionic cholinergic neurones, and contain muscarinic receptors.
In the paracervical ganglion (PCG) of the rat, double-labelling immunofluorescence for catecholamine-synthesizing enzymes and HPLC measurement of catecholamine contents were first performed to evaluate whether intraganglionic small intensely fluorescent (SIF) cells are capable of synthesizing adrenaline. Immunolabelling for tyrosine hydroxylase (TH), dopamine beta-hydroxylase and phenylethanolamine-N-methyl transferase (PNMT) occurred in all SIF cells of the PCG, thus demonstrating the presence of all the enzymes required for adrenaline biosynthesis. Adrenaline levels were undetectable in the PCG but to test the hypothesis that PNMT is active in SIF cells, catecholamines were measured in ganglia of rats pretreated with pargyline, an inhibitor of the monoamine oxidase, the major enzyme involved in the catecholamine degradation. Pargyline treatment increased adrenaline levels in the PCG, thus demonstrating that SIF cells are capable of adrenaline synthesis. The undetectable levels of adrenaline in the PCG of untreated rats suggested a slow rate of biosynthesis of adrenaline in the ganglion. Furthermore, the use of double-labelling showed that SIF cells of the PCG were stained for muscarinic receptors and were approached by varicose ChAT-immunoreactive nerve fibres. Nerve fibres immunoreactive for ChAT were also observed associated with nerve cell bodies of ganglion neurones. Following deafferentation of the PCG, the ChAT-immunoreactive nerve fibres surrounding nerve cell bodies totally disappeared indicating their preganglionic origin, while those associated with SIF cells did not degenerate, which demonstrate that they derived from intraganglionic cholinergic neurones. Taken together, the results show that adrenaline may be a transmitter for SIF cells in the PCG and suggest that cholinergic neurones of the parasympathetic division of the PCG can modulate the SIF cell activity through the activation of muscarinic receptors.
Topics: Afferent Pathways; Animals; Autonomic Fibers, Postganglionic; Cell Line; Cell Size; Choline O-Acetyltransferase; Dopamine beta-Hydroxylase; Epinephrine; Female; Fluorescent Antibody Technique; Ganglia, Sympathetic; Immunohistochemistry; Neurons; Phenylethanolamine N-Methyltransferase; Rats; Rats, Sprague-Dawley; Receptors, Muscarinic; Tyrosine 3-Monooxygenase
PubMed: 10064798
DOI: 10.1016/s0006-8993(99)01094-x -
Muscle & Nerve Sep 1986We measured distal sympathetic and vagal function in 73 consecutive patients with diabetic neuropathy seen at the Mayo Autonomic Reflex Laboratory. Postganglionic...
We measured distal sympathetic and vagal function in 73 consecutive patients with diabetic neuropathy seen at the Mayo Autonomic Reflex Laboratory. Postganglionic sympathetic failure measured proximally within the foot occurred as commonly as vagal failure (58% and 55%, respectively) and occurred much more frequently than did orthostatic hypotension (26%). Either vagal or distal sympathetic abnormalities occurred in isolation in about one in six patients with diabetic neuropathy. We conclude that distal sympathetic failure and vagal failure occur with equal frequency when sensitive and quantitative recording methods are used and that it is advantageous to test both systems, as only one may be involved in some patients.
Topics: Adult; Aged; Autonomic Fibers, Postganglionic; Autonomic Nervous System Diseases; Axons; Diabetic Neuropathies; Heart Rate; Humans; Middle Aged; Pilocarpine; Reflex, Abnormal; Sweating; Sympathetic Nervous System; Vagus Nerve
PubMed: 3762580
DOI: 10.1002/mus.880090703 -
Brain Research Dec 1978Previous work has suggested that cerebellum may control the size of the pupil and transmission in the pathway mediating the pupillary light reflex. In this work we found...
Previous work has suggested that cerebellum may control the size of the pupil and transmission in the pathway mediating the pupillary light reflex. In this work we found that electrical stimulation of the cerebellar nuclei (nucleus fastigius and nucleus interpositus bilaterally) evoked a discharge in the short ciliary nerves which innervate the intraocular muscles. The latency was 5.7 msec, which is short enough for a direct excitatory connexion from cerebellar efferents onto the preganglionic neurones in the Edinger-Westphal nucleus. These neurones are controlling the ciliary muscle of the lens system as well as the constrictor muscle of the pupil and it was therefore important to elucidate whether both of these groups participate in the discharge. Studies on interaction between the response to cerebellar stimulation and 'pupilloconstrictor' responses from optic tract fibres as well as recording from individual cells in the ciliary ganglion (identified with diffuse light stimuli) led to the conclusion that the short latency excitation is more or less confined to units controlling accommodation. Cerebellar inhibition (or disfacilitation) of longer latency affects both pupilloconstrictor and accommodation units.
Topics: Accommodation, Ocular; Animals; Autonomic Fibers, Postganglionic; Autonomic Fibers, Preganglionic; Brain Stem; Cats; Cerebellar Cortex; Cerebellar Nuclei; Cerebellum; Cerebral Aqueduct; Ciliary Body; Electric Stimulation; Evoked Potentials; Optic Nerve; Reflex, Pupillary; Synaptic Transmission
PubMed: 215268
DOI: 10.1016/0006-8993(78)90534-6 -
Acta Anaesthesiologica Scandinavica Jul 1988The aim of the study was to compare the effect of halothane anaesthesia on sympathetic nerve discharge in mechanically normoventilated and spontaneously breathing rats.... (Comparative Study)
Comparative Study
The aim of the study was to compare the effect of halothane anaesthesia on sympathetic nerve discharge in mechanically normoventilated and spontaneously breathing rats. Renal sympathetic nerve activity (rSNA), mean arterial pressure (MAP) and heart rate (HR) were measured in the conscious state and at the inspiratory halothane concentrations of 0.6%, 1.2% and 2.4% in one mechanically normoventilated and one spontaneously breathing group, while a third group was subjected to controlled hypoventilation at 1.2% halothane concentration. Halothane in blood was determined in two separate groups at 1.2%. In an additional group of spontaneously breathing rats, PaCO2 was analysed during consciousness and the halothane concentrations of 1.2% and 2.4%. There was a pronounced decrease in rSNA, MAP and HR at all levels of anaesthesia in the mechanically ventilated rats. However, rSNA, HR and MAP were significantly higher in the spontaneously breathing rats at increasing levels of halothane anaesthesia. Controlled hypoventilation at 1.2% halothane increased the variables significantly. In spontaneously breathing animals, PaCO2 increased significantly during the halothane exposure. The concentration of halothane in blood was significantly higher in the spontaneously breathing rats. Thus, the halothane-induced respiratory depression in the spontaneously breathing rats preserved rSNA during halothane anaesthesia, possibly via CO2-mediated chemoreceptor stimulation.
Topics: Anesthesia, Inhalation; Animals; Autonomic Fibers, Postganglionic; Blood Pressure; Halothane; Heart Rate; Kidney; Male; Rats; Rats, Inbred WKY; Respiration; Respiration, Artificial
PubMed: 3414350
DOI: 10.1111/j.1399-6576.1988.tb02757.x -
Bulletin de La Societe Des Sciences... 1978
Topics: Adrenergic Fibers; Adrenergic beta-Antagonists; Arrhythmias, Cardiac; Autonomic Fibers, Postganglionic; Autonomic Nervous System; Coronary Disease; Humans; Hypertension; Neurotransmitter Agents; Receptors, Adrenergic
PubMed: 29713
DOI: No ID Found -
Acta Physiologica Scandinavica Sep 1972
Topics: Acetylcholine; Animals; Autonomic Fibers, Postganglionic; Dogs; Electric Stimulation; Maxillary Artery; Neurosecretion; Parasympathetic Nervous System; Parotid Gland; Perfusion
PubMed: 4638315
DOI: 10.1111/j.1748-1716.1972.tb00229.x -
The Journal of Urology Apr 2002Guinea pig seminal vesicle smooth muscle displays an initial androgen dependent, proliferative response during early puberty, followed by progression to an androgen...
PURPOSE
Guinea pig seminal vesicle smooth muscle displays an initial androgen dependent, proliferative response during early puberty, followed by progression to an androgen resistant, amitotic state in adults. We determined the role of norepinephrine in androgen dependent pubertal proliferation and in the subsequent terminal differentiation of adult seminal vesicle smooth muscle.
MATERIALS AND METHODS
Guinea pig seminal vesicle provided a suitable model since its unique anatomy allowed clean harvest of smooth muscle without epithelium. Norepinephrine release from postganglionic adrenergic nerve terminals in seminal vesicle smooth muscle was measured using several techniques. Prazosin sensitive electrical field stimulation of contractile responses qualitatively assessed norepinephrine release. Norepinephrine release was quantified directly in vitro from incubated seminal vesicle smooth muscle minces and indirectly ex vivo from intact tissue using the endogenous seminal vesicle smooth muscle concentration ratio of 3,4-dihydroxyphenylglycol-to-norepinephrine (Sigma Chemical Co., St. Louis, Missouri). Norepinephrine mediated seminal vesicle smooth muscle proliferation was assessed by the time course relationships of androgen induced norepinephrine release, protein kinase C activation-depletion and increases in total DNA, the impact of in vivo reserpine induced norepinephrine depletion on protein kinase C activation-depletion and the mitogenic response, and the alpha1-adrenoceptor mediated mitogenic response in cultured seminal vesicle smooth muscle cells.
RESULTS
In prepubertal smooth muscle androgen induced norepinephrine release from postganglionic neurons. The effect was independent of preganglionic innervation. Increased norepinephrine release was concurrent with the onset of androgen induced protein kinase C activation-depletion and cellular proliferation. In vivo norepinephrine depletion to 1% or less of control values by chronic reserpine treatment selectively antagonized the androgen induced increases in smooth muscle DNA and protein kinase C down-regulation. Norepinephrine depletion by reserpine neither induced apoptosis nor altered cell number. Cell culture experiments demonstrated that alpha1-adrenoceptors mediated the proliferative response to norepinephrine. Together these findings indicate that increased norepinephrine release has an obligatory role in androgen dependent muscle cell proliferation during puberty. Terminally differentiated smooth muscle in adults was characterized by androgen resistance to elevated norepinephrine release and protein kinase C activation.
CONCLUSIONS
Androgen induced norepinephrine release from postganglionic neurons in seminal vesicle smooth muscle mediated the proliferative response that occurs in early pubertal development. Normal uncoupling of elevated norepinephrine release and protein kinase C activation-depletion may represent a key event in the normal terminal differentiation of accessory sex organ smooth muscle in adults.
Topics: Animals; Autonomic Fibers, Postganglionic; Cell Division; Dihydrotestosterone; Guinea Pigs; Male; Methoxyhydroxyphenylglycol; Muscle, Smooth; Norepinephrine; Seminal Vesicles
PubMed: 11912456
DOI: No ID Found -
The Journal of Comparative Neurology Jan 2004The sympathetic division of the autonomic nervous system is known to play a role in the genesis of neuropathic pain. In the skin of the rat lower lip (hairy skin),... (Comparative Study)
Comparative Study
The sympathetic division of the autonomic nervous system is known to play a role in the genesis of neuropathic pain. In the skin of the rat lower lip (hairy skin), sympathetic and parasympathetic fibers normally innervate the same blood vessels in the lower dermis but do not occur in the upper dermis. However, we have shown that sympathetic fiber migration into the upper dermis occurs following mental nerve lesions (Ruocco et al. [2000] J. Comp. Neurol. 422:287-296). As sensory denervation has a dramatic effect on sympathetic fiber innervation patterns in the rat lower lip skin, we decided to investigate the possible changes in the other autonomic fiber type in the skin-the parasympathetic fiber. Sensory denervation of the rat lower lip was achieved by bilateral transection of the mental nerve, and animals were allowed to recover for 1-8 weeks. Lower lip tissue was processed for double-labeling light microscopic immunocytochemistry (ICC), using antibodies against substance P (SP), which labels a subpopulation of peptidergic sensory fibers, and against the vesicular acetycholine transporter (VAChT), as a marker for parasympathetic fibers. In sham-operated rats, SP-immunoreactive (IR) sensory fibers were found in the epidermis and upper and lower dermal regions, whereas VAChT-IR fibers were confined to the lower dermis. Mental nerve lesions induced the gradual disappearance of SP-IR fibers from all skin layers accompanied by the progressive migration of VAChT-IR fibers into the upper dermis. Cholinergic fiber migration was evident by the second week post surgery, and the ectopic innervation of the upper dermis by these fibers persisted even at the last time point studied (8 weeks) when SP-IR fibers have completely regrown. VAChT-IR fibers were observed in the upper dermis, well above the opening of the sebaceous glands into the hair follicles. These results show that considerable changes occur in the innervation patterns of parasympathetic fibers following mental nerve lesions.
Topics: Animals; Dermis; Lip; Male; Parasympathectomy; Parasympathetic Fibers, Postganglionic; Rats; Rats, Wistar; Skin
PubMed: 14689474
DOI: 10.1002/cne.10998