A comparative study of the innervation of the choroid plexus in amphibia

The aminergic and cholinergic innervation of choroid plexuses in three species of amphibia was investigated. Plexuses of the Japanese toad and the bullfrog had poor innervation by adrenergic nerves of sympathetic origin, but in the clawed toad, these plexuses were heavily innervated by adrenergic axons from ganglion cells located in the plexus stroma. Nerve fibers positive for acetylcholinesterase were not found in the plexuses, except for a few fibers with very weak enzyme activity in the clawed toad.     

Cholinergic nerves in the rat portal vein

Summary The innervation of the rat portal vein was studied using the cholinesterase histochemical method 2 plexuses of cholinergic nerve fibers were found; an external plexus localized at the level of the outer adventitial layers and an inner plexus at the level of the adventitial-medial transitional zone and in the outer layers of the media.Acknowledgments. We thank Dr C. Cavallotti for his kind help and criticism. The kind help of Dr W. Collier and of the staff of the laboratory of Neurobiology as well as the bibliographic assistance of Istituto Superiore di Sanità (Serv. Documentazione, Dr Magliola) are gratefully acknowledged.     

Nonsympathetic dilator innervation of cat cerebral arteries.

The results presented provide strong support for the presence of vasodilator innervation in the cat cerebral arteries. The dilator innervation is neither adrenergic nor cholinergic and does not originate in the superior cervical ganglia. The nature of the vasodilator transmitter is unidentified. Such innervation, however, may be involved in the regulation of cerebral blood flow, especially in view of the capability of some cat cerebral vessels to develop intrinsic muscle tone.     

Peptidergic innervation of the temporomandibular disk in the rat

Summary The peptidergic innervation of the temporomandibular disk was investigated in the postnatal young rat by using an indirect immunofluorescence method. Calcitonin gene-related peptide-containing nerve fibers were located around the blood vessels and terminated as free nerve endings in the disk. These nerve fibers may be of a sensory nature.     

Peptidergic innervation of the temporomandibular disk in the rat

The peptidergic innervation of the temporomandibular disk was investigated in the postnatal young rat by using an indirect immunofluorescence method. Calcitonin gene-related peptide-containing nerve fibers were located around the blood vessels and terminated as free nerve endings in the disk. These nerve fibers may be of a sensory nature.     

Morphological evidence for a direct neuroendocrine GABAergic control of the anterior pituitary in teleosts

Summary The anterior pituitary of teleosts is unique among vertebrates in receiving a direct innervation which represents the morphological support of the neuroendocrine control of pars distalis functions. The participation of GABAergic fibers in this innervation was studied by means of immunocytochemistry at the light and electron microscopic levels, using antibodies against GABA. Immunoreactive fibers, characterized by the presence of small clear and dense cored vesicles, were detected in all parts of the gland. Immunopositive terminals were found in close, sometimes synaptic-like, contact with most glandular cell types in the anterior lobe. The data strongly suggest that in teleosts, as in mammals, GABA is involved in the neuroendocrine control of anterior pituitary functions.     

Morphological evidence for a direct neuroendocrine GABAergic control of the anterior pituitary in teleosts

The anterior pituitary of teleosts is unique among vertebrates in receiving a direct innervation which represents the morphological support of the neuroendocrine control of pars distalis functions. The participation of GABAergic fibers in this innervation was studied by means of immunocytochemistry at the light and electron microscopic levels, using antibodies against GABA. Immunoreactive fibers, characterized by the presence of small clear and dense cored vesicles, were detected in all parts of the gland. Immunopositive terminals were found in close, sometimes synaptic-like, contact with most glandular cell types in the anterior lobe. The data strongly suggest that in teleosts, as in mammals, GABA is involved in the neuroendocrine control of anterior pituitary functions.     

Adrenergic reinnervation of the denervated rat urinary bladder.

In rats undergoing unilateral extirpation of the pelvic ganglion, the adrenergic innervation disappeared on the ipsilateral side of the urinary bladder. It had reappeared after 6--9 weeks.     

Adrenergic reinnervation of the denervated rat urinary bladder

Summary In rats undergoing unilateral extirpation of the pelvic ganglion, the adrenergic innervation disappeared on the ipsilateral side of the urinary bladder. It had reappeared after 6–9 weeks.This work was supported by grants from the Faculty of Medicine in Lund to M.E.     

Identification of GABA accumulating neurons in the dorsal raphe nucleus]

A possible GABAergic innervation of the nucleus raphe dorsalis (NRD) was investigated by measuring glutamate decarboxylase activity in the NRD after lesioning the afferents of this nucleus. The slight decrease found in the enzymatic activity suggests that these afferents have a minor participation in the GABA innervation of the NRD and implies the existence of an intrinsic GABAergic system in this nucleus. This local innervation was demonstrated by radio-autography and shows fibers, axonal varicosities and cell bodies which accumulate 3H GABA in the caudal part of this nucleus.     

Pathways for excitatory and inhibitory innervation to the guinea-pig tracheal smooth muscle.

The trachea receives excitatory cholinergic innervation from the vagus nerve and the stellate ganglion. Inhibitory adrenergic fibres have the same sources. Those in the vagus nerve probably derive from high vagosympathetic anastomoses. Nonadrenergic inhibitory fibres have a preganglionic vagal supply.     

Pathways for excitatory and inhibitory innervation to the guinea-pig tracheal smooth muscle

Summary The trachea receives excitatory cholinergic innervation from the vagus nerve and the stellate ganglion. Inhibitory adrenergic fibres have the same sources. Those in the vagus nerve probably derive from high vagosympathetic anastomoses. Nonadrenergic inhibitory fibres have a preganglionic vagal supply.This study has been supported by grants from Magnus Bergvall Memorial Found and Harald and Greta Jeansson Foundation.     

An electron microscopic study on the autonomic innervation of the rabbit parotid gland

Summary As visualized in the electron microscope, the parotid gland of the rabbit has a dual innervation. Both adrenergic and cholinergic nerves are equally distributed in the parenchyma and often run together within the same nerve bundle. Nerve terminals are observed not only subjacent to the basement membrane but interposed between the latter and the acinar cells, where they establish a close membrane to membrane contact with the latter.This investigation was supported by grants from Svenska Medicinska Sällskapet and the University of Umeå.     

Effect of a dipeptide inhibiting ubiquitin-mediated protein degradation on nerve-dependent limb regeneration in the newt

The dipeptide Leu-Ala, which inhibits ubiquitin-mediated protein degradation, has been shown to act in vitro as an inhibitor of neurite outgrowth of PC12 cells (Hondermarck et al. [1992] Biochem. Biophys. Res. Commun.189: 280). Using agarose beads as vehicles, we tested, in vivo, the effect of this dipeptide (and the inactive inverse, Ala-Leu, as a control) on limb regeneration in the newt (Triturus cristatus), a nerve-dependent developmental process. Leu-Ala inhibited the growth of mid-bud blastemas without altering blastema differentiation, while Ala-Leu had no effect. Cytological observations of dipeptide-treated blastemas using Bodian staining or neurofilament antibodies showed that all the blastema tissues were unmodified except with regard to innervation. Leu-Ala-treated blastemas were devoid of nerve fibers in the epidermal cap, while the mesenchyme distal to the dipeptide impregnated bead exhibited fewer nerve fibers than did Ala-Leu-treated blastemas, which were similar to the control nontreated blastemas. Thus, Leu-Ala, in reducing blastema innervation, inhibits its growth in the same manner as surgical denervation.     

Effect of 5,7-dihydroxytryptamine on Auerbach's plexus in the ileum of guinea-pig

Action of 100 mg/kg of 5,7-dihydroxytryptamine on Auerbach's plexus in the ileum of the guinea-pig has been studied using Falck and Hillarp's formaldehyde condensation technique. The drug caused partial disappearance of the adrenergic nerve profiles initially but after 10 days of treatment all the lost fibers reappeared.     

Studies on some enzymes of the toad (Bufo melanostictus) testis and their probable role at the time of fertilization

Summary Glycosidases like sialidase,-galactosidase, -L-fucosidase, N-acetyl hexosaminidase and proteases were detected in toad testis. Neuraminic acid aldolase activity was also detected. The enzyme activities were found to vary as production of spermatozoa varied. All enzymes, except N-acetyl glucosaminidase, were shown to decrease after injection of toad pituitary extract and they were also found to be absent from testis containing no spermatozoa. The glycosidases were found to act on toad oviduct jelly and they may therefore be involved in the degradation of the jelly after fertilization, into smaller bits, which may be utilized as nutrients by the fertilized zygote.Acknowledgment. We thank Prof. T.R. Ramaiah, Head of the Department of Biochemistry, University of Mysore, for his help. We also acknowledge the financial assistance of University Grants Commission to one of us (MS) and CSIR through a grant No. 9 (165)83/EMR-II to HSS. Please address all correspondence to H.S. Seshadri.     

Comparative cytochemical and pharmacological studies on the cholinergic innervation of the branchial heart of the cephalopodSepia officinalis (L.)

Summary The dense motor innervation of the obliquely striated muscle cells in the branchial heart of Coleoida is composed of activating and inhibiting parts. The inhibiting cholinergic system investigated in this study is characterized histo- and cytochemically by a high acetylcholinesterase activity (EC 3.1.1.7) in the glycocalices of the nerve fibers with transparent synaptic vesicles, the muscle cells and, to a lesser extent, the ovoid interstitial cells, the functions of which are endocytosis and storage of catabolic substances. The pharmacological results from the isolated organ indicate a more nicotinic type of Ach-receptor, which can be reversibly blocked by D-tubocurarine and -bungarotoxin, but not with the same intensity by tetraethylammonium or atropine.     

A quantitative study of the catecholamine-fluorescence in the ganglion paracervicale uteri of the rat

Summary In the ganglion paracervicale uteri of the rat, there are principle neurons which are able to take up offered catecholamines. Normally there is an inverse relationship between their size and their mean catecholamine-fluorescence. A comparison with the catecholamine-fluorescence of depleted and repleted adrenergic perikarya in the ganglion cervicale superius is made.Acknowledgments. I am very obliged to Dr G. Krinke and to Mrs K. Schnider for their continued interest and practical assistance. The study was supported in part by CIBA-GEIGY, Ltd. Basle.     

On the adrenergic innervation of the rat parotid gland

Summary In parotid glands of rats, some adrenergic nerves persisted after avulsion of the superior cervical ganglion, while in submaxillary glands, the adrenergic nerves disappeared completely.This work was supported by grants from the Faculty of Medicine in Lund to J. E.     

Activation of sustained sympathetic vasodilatation in dog by spinal cord stimulation.

Electrical stimulation in lateral sites of the upper cervical spinal cord evoked vasodilatation after adrenergic blockade. Sympathetic fibres mediating sustained vasodilatation were shown to be separate from adrenergic sympathetic fibres since the adrenergic vasoconstrictor response in the paw evoked by vasomotor stimulation in the medulla was not reversed to vasodilatation after bretylium.