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Parasympathetic innervation to STM was activated by superior salivatory nucleus (SSN) stimulation at 35 days post-SNX. SSN stimulation elicited contractions of ...

JASYDS 65 (2/3) 67-168 (1997)

Journal of the

Autonomic Nervous

f

System Completing Volume 65

SPECIAL ISSUE

ABSTRACTS FOR THE INAUGURAL CONFERENCE OF THE

INTERNATIONAL SOCIETY FOR AUTONOMIC NEUROSCIENCE

(ISAM)

Elsevier

Journal of the

Autonomic

Nervous

System

VOL. 65, No. 2-3(1997)

SPECIAL ISSUE - ISAM ABSTRACTS

ELSEVIER

Amsterdam - Lausanne - New York - Oxford - Shannon - Tokyo

y

...

/Journal of the Autonomic Nervous System 65 (1997) 115-119

Novel axo-somatic associations formed in the pelvic ganglia after spinal nerve injury M E Kepper and J.R. Keast Department of Physiology and Pharmacology, The University of Queensland, Qld. 4072, Australia .

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117

whether catecholaminergic mechanisms play a role in parasympathetic excitation after SNX. Parasympathetic innervation to STM was activated

by superior salivatory nucleus (SSN) stimulation at 35 days post-SNX. SSN stimulation elicited contractions of 540±60 mg (yV= 16). The a-\ adrenergic antagonist prazosin decreased contractions by 37±4% (P < 0 05) whereas the a-2 antagonist idazoxan had no significant additional effect. Spinal cord transection reduced contractions comparably to a-\ .

The rat pelvic ganglia innervate the urogenital and lower digestive tracts. Our study examined the possibility of novel connections (sprouts) forming within these ganglia after transection of lumbar and/or sacral spinal nerves. Sprout formation was visualised by immunolabelling markers for postganglionic neurons. Within 4 days of nerve transection, sprouts formed basket-like associations with pelvic ganglia somata. After removal of all preganglionic innervation these associations were equally distributed between neurons innervating each of the pelvic organs. However, after either sympathetic or parasympathetic decentralisation sprouts formed only around decentralised neurons, leading us to hypothesise that ,

blockade, and residual contractions were abolished by atropine. Continuous infusion of phenylephrine, an a-1 agonist, in spinally transected rats augmented contractions to SSN stimulation by 21 ±7% (/> = 0.03) but not those evoked by the muscarinic agonist bethanechol. RT-PCR revealed a-1 receptor mRNA in parasympathetic pterygopalatine ganglia. We conclude that circulating catecholamines play a role in STM parasympathetic excitation after SNX by activating parasympathetic neuronal a-\ receptors that facilitate acetylcholine release. Supported by NIH HD33025.

,

in partially decentralised ganglia, neurons with intact spinal innervation form sprouts to innervate decentralised somata. If a synapse forms. functional reflex pathways would result. Restoration of reflex pathways has also been suggested by other investigators using electrophysiological recordings in partially decentralised ganglia. However, quite a different

The role of the sympathetic scrvous system in plasticity of the injured spinal cord L A Matinyan Orheli Institute of Physiology of NASRA, 22 Orheli Bros. St., Yerevan .

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375028. Armenia

type of remodelling was hypothesised, where intact preganglionic axons contributed sprouts. Our studies suggest that this is not the case. Investigations are currently being carried out to examine the distribution of

several neurotrophic factors and their receptors in the pelvic ganglia

,

which may play a role in sprout formation.

The role of the sympathetic nervous system (SNS) is well revealed in heavy states of organism, but its significance changes according to the phylogenetic level. We examined the relationship between the SNS and spinal cord injury in 55 adult white rats using clinical, electrophysiological. histochemical, and statistical methods. These studies showed, that

after the bilateral removal of the abdominal sympathetic tubes, lateral

Ultrastructure of autonomic and somatic nerve and glial cells exposed to hypothermia 1). Krajci Department of Anatomy and E.M. Unit, Faculty of Medicine, Kuwait University, Kuwait

In hibemators and some non-hibemating animals subjected to induced hypothermia the neurons of the brain, spinal cord and spinal ganglia were reported with ultrastructure changes in their cytoplasm. In this study autonomic ganglia of the same animals are examined and their ultrastructure compared with the sensory ganglia. Three adult female cats were premedicated. anesthetized and supported by artificial ventilation with

endotracheal intubation. Their body temperature was cooled by crushed ice and rectal temperature was decreased to 30oC 2TC and 20oC, respectively, for a period of 5-8 h. The experiment was terminated by transcardial perfusion of the fixative solution. Paravertebral sympathetic ganglia, spinal ganglia and trigeminal ganglia were dissected and processed for EM. The sensory ganglia in both locations contained neurons ,

hcmisection of the spinal cord (SC) in rats causes deeper violations of functions (somatovegetative, trophic), than docs hcmisection alone. Functional recovery also ensues rather later (2-3 times). Even after 5.5 months, in the sympathectomized animals with a SC hcmisection there was a statistically marked slowing down of the carrying rate and a prolongation of the latest period of the cortex potential with a decrease in its amplitude. In such animals, the morpho-histochemical picture is characterized by more strongly expressed destructive processes and less compensation as compared with those rats, which had only hcmisection. Thus, these data indicate that the SNS plays an important role in the responses of rats to hcmisection of the SC.

Neonatal removal of superior cervical ganglion (SCG) induces degeneration of sympathetic preganglionic neurons (SPN) P Poulat and A. Privat .

INSERM U-336. USTL Montpellier, France

with extensive alterations of membranes of GER in the form of convo-

luted patterns. Their neuro-glial relations were also altered In the sympa.

thetic ganglia the neurons did not respond to the hypothermia to the same extent. The ultrastructure of their organelles as well as the satellite cell envelope was found well preserved. These results indicate a different reactivity of these cells expressed in distinct alterations of their proteosynthetic apparatus.

Adrenergic modulation of parasympathetic neurotransmission in sympathetically denervated superior tarsal smooth muscle Dora Krizsan-Agbas, Ren-jie Zhang Farshid Marzban and Peter G. .

Smith

Department of Molecular and Integrative Physiology University of Kansas Medical Center, Kansas City KS 66160-7401, USA ,

,

Parasympathetic innervation to rat superior tarsal muscle (STM)

normalK inhihits sympathetic excitatory nerves prejunctiaaally

,

but elicits

muscarinic contraction after sympathectomy (SNX) This study examined .

SPN of the spinal cord are an essential part of the sympathetic nervous system. Their degeneration in various pathologies results in important autonomic dysfunction. In this study, degeneration of SPN was studied in a model of neonatal removal of right SCG in the rat. SPN were retrogradcly labelled by intraperitoneal injection of fast blue. Rats were fixed, T1-T4 spinal levels dissected and sliced. At 1, 3, 6 months post-lesion, a 50 to 95% loss of fast blue labelled SPN was detected in the various spinal autonomic subregions ipsilateral to the lesion. Double immunofiuorescent labelling of sections for choline-acelyltransferase and NO synthase further showed an important loss of such labelling in these regions. Lastly, paraffin embedded sections stained by cresyl violet, demonstrated a marked increase in the number of cells displaying apoptotic characteristics at 24, 36, 48 h post-lesion in the ipsilateral intermcdiolateral cell column. In conclusion, neonatal removal of SCG induces an

important degeneration of SPN which partly involves apoptotic mechanisms. This may thus represent a suitable model to study the degeneration and/or protection of SPN, Supported by the Medical Research Council of Great Britain and the Wellcome Trust