Document Detail


Formation of a functional adrenergic input to intraocular cerebellar grafts: ingrowth of inhibitory sympathetic fibers.
MedLine Citation:
PMID:  1185191     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The intraocular transplantation technique was used to study the ingrowth of peripheral sympathetic adrenergic nerves from the iris into transplants of fetal rat cerebellum, and the possible function of these nerves. The transplants, grown in oculo for one-half to eight months, were analyzed by fluorescence histochemistry and electrophysiological techniques. Peripheral sympathetic adrenergic fibers from the iris were able to grow into the cerebellar transplants and arborize in a pattern similar to that in situ, appearing in all three cortical layers and the noncortical areas of the transplants. The density of visible nerves without pretreatment and after preincubation in 10(-6) or 10(-5) M alpha-methylnorepinephrine was comparable to mature rat cerebellum. The spontaneous discharge of the Purkinje cells in oculo was inhibited by microiontophoresis of norepinephrine (NE) and amphetamine in sympathetically innervated, as well as sympathectomized transplants denervated by ganglionectomy. The NE response was blocked by the adrenergic beta-receptor blocker MJ-1999. GABA also inhibited the Purkinje cell activity while glutamate accelerated the discharge. Parenteral amphetamine inhibited Purkinje cell activity in sympathetically innervated transplants, but was ineffective in denervated transplants. The Purkinje cell spontaneous activity was inhibited by electrical stimulation of the NE fiber input through the cervical sympathetic trunk. This inhibition could be antagonized by parenteral reserpine or the beta-adrenergic antagonist propranolol. The responses of the Purkinje cells within the transplants to drugs and transmitters mimic those of the adult rat in situ. In view of the fluorescence histochemical evidence for an ingrowth of peripheral sympathetic adrenergic fibers into the cerebellar transplants, and the results of stimulating the sympathetic trunk, it is suggested that peripheral adrenergic fibers may be able to establish functional connections with the Purkinje cells similar to the cerebellar adrenergic synapses normally formed in situ by fibers from the locus coeruleus.
Authors:
B Hoffer; L Olson; A Seiger; F Bloom
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of neurobiology     Volume:  6     ISSN:  0022-3034     ISO Abbreviation:  J. Neurobiol.     Publication Date:  1975 Nov 
Date Detail:
Created Date:  1976-01-29     Completed Date:  1976-01-29     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0213640     Medline TA:  J Neurobiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  565-85     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Amphetamine / pharmacology
Animals
Catecholamines / metabolism
Cerebellum / embryology,  physiology,  transplantation*
Electrophysiology
Female
Glyoxylates / metabolism
Histocytochemistry
Iontophoresis
Microscopy, Fluorescence
Norepinephrine / pharmacology
Ocular Physiological Phenomena*
Purkinje Cells / physiology
Rats
Sympathetic Nervous System / physiology*
Chemical
Reg. No./Substance:
0/Catecholamines; 0/Glyoxylates; 300-62-9/Amphetamine; 51-41-2/Norepinephrine

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