Peter Baluk - Academia.edu (original) (raw)
Papers by Peter Baluk
Neuroscience Letters, 1989
Noradrenergic nerves were studied in whole-mount preparations of the rat, mouse and guinea pig tr... more Noradrenergic nerves were studied in whole-mount preparations of the rat, mouse and guinea pig trachea by means of glyoxylic acid-induced catecholamine fluorescence and dopamine fl-hydroxylase immunoreactivity. In an effort to raise tissue levels of catecholamines, some specimens were also treated with the monoamine oxidase inhibitor pargyline, and with L-DOPA, a precursor of noradrenaline. Noradrenergic nerve fibres were detected around blood vessels, within the tracheal smooth muscle and in the mucosa, but never around or in the proximity of neurons of the tracheal ganglia, even after amine precursor loading. These parasympathetic ganglion cells did not show catecholamine fluorescence under control conditions. In the rat and mouse, but not in the guinea pig, some tracheal neurones were dopamine fl-hydroxylase immunoreactive and showed uptake and metabolism of amine precursors, thus expressing aspects of the catecholaminergic phenotype.
Anatomy and Embryology, 1991
The trachea of guinea-pigs was stained as a whole-mount preparation with the zinc iodide-osmium t... more The trachea of guinea-pigs was stained as a whole-mount preparation with the zinc iodide-osmium technique. A distinct class of nerve endings was observed associated with the tracheal muscle. The endings, issued from myelinated fibres of the vagus nerve via the recurrent laryngeal nerve, are distributed on either side of the midline and ventral to the tips of cartilages. They are interpreted as afferent nerve endings that may correspond to slow adapting stretch receptors identified by physiological studies. Each nerve contributes predominantly, but not exclusively, to the receptors of the ipsilateral side. There are 120–180 receptors along the full length of the guinea-pig trachea, their density being higher at the cranial end. The receptors are variable in size and structural complexity, and, to some extent, also in spatial orientation, but distinct subtypes are not recognizable. Receptors of similar morphology and distribution are found also in the rat trachea. The receptors can also be visualized with a cytochrome oxidase method for nerve endings, but they do not stain with immunohistochemistry for the neuropeptides substance P, calcitonin gene-related peptide, vasointestinal polypeptide and neurotensin.
Journal of Comparative Neurology, 1989
The innervation of the guinea pig trachea was studied in wholemount preparations stained for acet... more The innervation of the guinea pig trachea was studied in wholemount preparations stained for acetylcholinesterase, catecholamines, and substance P immunoreactivity and by electron microscopy. The majority of parasympathetic and afferent nerve fibres arrive from the vagus via branches of the recurrent laryngeal nerves. The recurrent laryngeal nerves are composed of several fascicles comprising 600–700 small myelinated fibres (2–5 μm diameter) and about 1,000–2,000 unmyelinated fibres; both components exit from the nerve and project in fine branches to the trachea. A separate component of 200–250 large myelinated fibres (more than 5 μm diameter) runs the full length of the nerve and innervates the striated muscles of the larynx. The recurrent laryngeal nerves are slightly asymmetric in their origin, length, number, and composition of fibres, with the right nerve being shorter but with more numerous and thinner myelinated fibres. At the distal end of the recurrent nerve, a fine branch called the ramus anastomoticus connects it to the superior laryngeal nerve. In the tracheal plexus, there are on average 222 ganglion cells (range 166–327), distributed mostly in small ganglia of 12 or fewer neurons. The ganglionated plexus is situated entirely outside the tracheal wall, overlying the smooth muscle. Ligation experiments show that sympathetic nerve fibres reach the trachea with the recurrent nerves via anastomoses between the sympathetic chain and vagus nerves, or occasionally with recurrent nerves directly, the largest being at the level of the ansa subclavia. There are also perivascular sympathetic nerve plexuses. Substance P immunoreactive fibres enter the trachea from the vagus nerves and by pathways similar to those of sympathetic nerves. There are also paraganglion cells within the recurrent laryngeal nerve that contain catecholamines and are surrounded by substance P immunoreactive fibres.After cervical vagotomy, all the large myelinated fibres of the ipsilateral recurrent laryngeal nerve degenerate and so do all but 10 or 20 small myelinated fibres and all but a few unmyelinated fibres. Degenerating fibres are found within the entire tracheal plexus, indicating bilateral innervation. The small myelinated fibres that survive cervical vagotomy probably represent sympathetic or afferent nerves with their cell bodies located in sympathetic or dorsal root ganglia.
Cell and Tissue Research, 1990
In a histochemical study of intrinsic cardiac ganglia of the guinea-pig in whole-mount preparatio... more In a histochemical study of intrinsic cardiac ganglia of the guinea-pig in whole-mount preparations, it was found that some 70–80% of the neurons express aspects of the catecholaminergic phenotype. These neurons have an uptake mechanism for L-DOPA, and contain the enzymes for converting L-DOPA, (but not D-DOPA) to dopamine and noradrenaline, i.e. aromatic L-aminoacid decarboxylase and dopamine β-hydroxylase. Monoamine oxidase is also present within some of the neurons. In these respects, the neurons resemble noradrenergic neurons of sympathetic ganglia, so we refer to them as intrinsic cardiac amine-handling neurons. However, these neurons do not contain tyrosine hydroxylase and show little or no histochemically detectable uptake of α-methyldopa, dopamine or noradrenaline, even after depletion of endogenous stores of amines by pre-treatment with reserpine. Noradrenergic fibres from the sympathetic chain form pericellular baskets around nerve cell bodies. The uptake of L-DOPA into nerve cell bodies is not prevented by treatment with 6-hydroxydopamine sufficient to cause transmitter-depletion or degeneration of the extrinsic noradrenergic fibres. Such degeneration experiments suggest that axons of the amine-handling neurons project to cardiac muscle, blood vessels and other intrinsic neurons. The cardiac neurons do not show any immunohistochemically detectable serotonergic characteristics; there is no evidence for uptake of the precursors L-tryptophan and 5-hydroxytryptophan or 5-HT itself, whereas the extrinsic noradrer ergic nerve fibres within the ganglia can take up 5-HT when it is applied in high concentrations.
Cell and Tissue Research, 1987
We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic... more We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic and chemical removal of extracellular connective tissue. The cells of the longitudinal muscle layer are wider, have rougher surfaces, more finger-like processes and more complex terminations, but fewer intercellular junctions than cells in the circular muscle layer. A special layer of wide, flat cells with a dense innervation exists at the inner margin of the circular muscle layer, facing the submucosa. The ganglia of the myenteric and submucosal plexuses are covered by a smooth basal lamina, a delicate feltwork of collagen fibrils, and innumerable connective tissue cells. The neuronal and glial cell processes at the surface of ganglia form an interlocking mosaic, which is loosely packed in newborn and young animals, but becomes tightly packed in adults. The arrangement of glial cells becomes progressively looser along finer nerve bundles. Single varicose nerve fibres are rarely exposed, but multiaxonal bundles are common. Fibroblast-like cells of characteristic shape and orientation are found in the serosa; around nerve ganglia; in the intermuscular connective tissue layer and in the circular muscle, where they bridge nerve bundles and muscle cells; at the submucosal face of the special, flattened inner circular muscle layer; and in the submucosa. Some of these fibroblast like cells correspond to interstitial cells of Cajal. Other structures readily visualized by scanning electron microscopy are blood and lymphatic vessels and their periendothelial cells. The relationship of cellular elements to connective tissue was studied with three different preparative procedures: (1) freeze-cracked specimens of intact, undigested intestine; (2) ‘stretch preparations’ of longitudinal muscle with adhering myenteric plexus; (3) sheets of submucosal collagen bundles from which all cellular elements had been removed by prolonged detergent extraction.
Neuroscience Letters, 1989
Whole-mount preparations of the posterior wall of the atria of the guinea pig heart containing in... more Whole-mount preparations of the posterior wall of the atria of the guinea pig heart containing intrinsic ganglion cells and nerve plexuses were stained for substance P-like immunoreactivity by the peroxidaseantiperoxidase method. Substance P-like nerve fibres are present as pericellular baskets around most, but not all, of the neuronal cell bodies, and are also found in the connecting nerve bundles, as perivascular nerve plexuses and in the myocardium and pericardium. The majority of ganglion cell bodies are negative for substance P, as reported previously, but we describe for the first time, a small subpopulation of intrinsic neuronal cell bodies which show immunoreactivity for substance P. Therefore, not all cardiac substance P nerves are extrinsic afferent fibres. At present, the physiological role of intrinsic substance P neurones is not clear.
Neuroscience Letters, 1989
Noradrenergic nerves were studied in whole-mount preparations of the rat, mouse and guinea pig tr... more Noradrenergic nerves were studied in whole-mount preparations of the rat, mouse and guinea pig trachea by means of glyoxylic acid-induced catecholamine fluorescence and dopamine fl-hydroxylase immunoreactivity. In an effort to raise tissue levels of catecholamines, some specimens were also treated with the monoamine oxidase inhibitor pargyline, and with L-DOPA, a precursor of noradrenaline. Noradrenergic nerve fibres were detected around blood vessels, within the tracheal smooth muscle and in the mucosa, but never around or in the proximity of neurons of the tracheal ganglia, even after amine precursor loading. These parasympathetic ganglion cells did not show catecholamine fluorescence under control conditions. In the rat and mouse, but not in the guinea pig, some tracheal neurones were dopamine fl-hydroxylase immunoreactive and showed uptake and metabolism of amine precursors, thus expressing aspects of the catecholaminergic phenotype.
Anatomy and Embryology, 1991
The trachea of guinea-pigs was stained as a whole-mount preparation with the zinc iodide-osmium t... more The trachea of guinea-pigs was stained as a whole-mount preparation with the zinc iodide-osmium technique. A distinct class of nerve endings was observed associated with the tracheal muscle. The endings, issued from myelinated fibres of the vagus nerve via the recurrent laryngeal nerve, are distributed on either side of the midline and ventral to the tips of cartilages. They are interpreted as afferent nerve endings that may correspond to slow adapting stretch receptors identified by physiological studies. Each nerve contributes predominantly, but not exclusively, to the receptors of the ipsilateral side. There are 120–180 receptors along the full length of the guinea-pig trachea, their density being higher at the cranial end. The receptors are variable in size and structural complexity, and, to some extent, also in spatial orientation, but distinct subtypes are not recognizable. Receptors of similar morphology and distribution are found also in the rat trachea. The receptors can also be visualized with a cytochrome oxidase method for nerve endings, but they do not stain with immunohistochemistry for the neuropeptides substance P, calcitonin gene-related peptide, vasointestinal polypeptide and neurotensin.
Journal of Comparative Neurology, 1989
The innervation of the guinea pig trachea was studied in wholemount preparations stained for acet... more The innervation of the guinea pig trachea was studied in wholemount preparations stained for acetylcholinesterase, catecholamines, and substance P immunoreactivity and by electron microscopy. The majority of parasympathetic and afferent nerve fibres arrive from the vagus via branches of the recurrent laryngeal nerves. The recurrent laryngeal nerves are composed of several fascicles comprising 600–700 small myelinated fibres (2–5 μm diameter) and about 1,000–2,000 unmyelinated fibres; both components exit from the nerve and project in fine branches to the trachea. A separate component of 200–250 large myelinated fibres (more than 5 μm diameter) runs the full length of the nerve and innervates the striated muscles of the larynx. The recurrent laryngeal nerves are slightly asymmetric in their origin, length, number, and composition of fibres, with the right nerve being shorter but with more numerous and thinner myelinated fibres. At the distal end of the recurrent nerve, a fine branch called the ramus anastomoticus connects it to the superior laryngeal nerve. In the tracheal plexus, there are on average 222 ganglion cells (range 166–327), distributed mostly in small ganglia of 12 or fewer neurons. The ganglionated plexus is situated entirely outside the tracheal wall, overlying the smooth muscle. Ligation experiments show that sympathetic nerve fibres reach the trachea with the recurrent nerves via anastomoses between the sympathetic chain and vagus nerves, or occasionally with recurrent nerves directly, the largest being at the level of the ansa subclavia. There are also perivascular sympathetic nerve plexuses. Substance P immunoreactive fibres enter the trachea from the vagus nerves and by pathways similar to those of sympathetic nerves. There are also paraganglion cells within the recurrent laryngeal nerve that contain catecholamines and are surrounded by substance P immunoreactive fibres.After cervical vagotomy, all the large myelinated fibres of the ipsilateral recurrent laryngeal nerve degenerate and so do all but 10 or 20 small myelinated fibres and all but a few unmyelinated fibres. Degenerating fibres are found within the entire tracheal plexus, indicating bilateral innervation. The small myelinated fibres that survive cervical vagotomy probably represent sympathetic or afferent nerves with their cell bodies located in sympathetic or dorsal root ganglia.
Cell and Tissue Research, 1990
In a histochemical study of intrinsic cardiac ganglia of the guinea-pig in whole-mount preparatio... more In a histochemical study of intrinsic cardiac ganglia of the guinea-pig in whole-mount preparations, it was found that some 70–80% of the neurons express aspects of the catecholaminergic phenotype. These neurons have an uptake mechanism for L-DOPA, and contain the enzymes for converting L-DOPA, (but not D-DOPA) to dopamine and noradrenaline, i.e. aromatic L-aminoacid decarboxylase and dopamine β-hydroxylase. Monoamine oxidase is also present within some of the neurons. In these respects, the neurons resemble noradrenergic neurons of sympathetic ganglia, so we refer to them as intrinsic cardiac amine-handling neurons. However, these neurons do not contain tyrosine hydroxylase and show little or no histochemically detectable uptake of α-methyldopa, dopamine or noradrenaline, even after depletion of endogenous stores of amines by pre-treatment with reserpine. Noradrenergic fibres from the sympathetic chain form pericellular baskets around nerve cell bodies. The uptake of L-DOPA into nerve cell bodies is not prevented by treatment with 6-hydroxydopamine sufficient to cause transmitter-depletion or degeneration of the extrinsic noradrenergic fibres. Such degeneration experiments suggest that axons of the amine-handling neurons project to cardiac muscle, blood vessels and other intrinsic neurons. The cardiac neurons do not show any immunohistochemically detectable serotonergic characteristics; there is no evidence for uptake of the precursors L-tryptophan and 5-hydroxytryptophan or 5-HT itself, whereas the extrinsic noradrer ergic nerve fibres within the ganglia can take up 5-HT when it is applied in high concentrations.
Cell and Tissue Research, 1987
We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic... more We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic and chemical removal of extracellular connective tissue. The cells of the longitudinal muscle layer are wider, have rougher surfaces, more finger-like processes and more complex terminations, but fewer intercellular junctions than cells in the circular muscle layer. A special layer of wide, flat cells with a dense innervation exists at the inner margin of the circular muscle layer, facing the submucosa. The ganglia of the myenteric and submucosal plexuses are covered by a smooth basal lamina, a delicate feltwork of collagen fibrils, and innumerable connective tissue cells. The neuronal and glial cell processes at the surface of ganglia form an interlocking mosaic, which is loosely packed in newborn and young animals, but becomes tightly packed in adults. The arrangement of glial cells becomes progressively looser along finer nerve bundles. Single varicose nerve fibres are rarely exposed, but multiaxonal bundles are common. Fibroblast-like cells of characteristic shape and orientation are found in the serosa; around nerve ganglia; in the intermuscular connective tissue layer and in the circular muscle, where they bridge nerve bundles and muscle cells; at the submucosal face of the special, flattened inner circular muscle layer; and in the submucosa. Some of these fibroblast like cells correspond to interstitial cells of Cajal. Other structures readily visualized by scanning electron microscopy are blood and lymphatic vessels and their periendothelial cells. The relationship of cellular elements to connective tissue was studied with three different preparative procedures: (1) freeze-cracked specimens of intact, undigested intestine; (2) ‘stretch preparations’ of longitudinal muscle with adhering myenteric plexus; (3) sheets of submucosal collagen bundles from which all cellular elements had been removed by prolonged detergent extraction.
Neuroscience Letters, 1989
Whole-mount preparations of the posterior wall of the atria of the guinea pig heart containing in... more Whole-mount preparations of the posterior wall of the atria of the guinea pig heart containing intrinsic ganglion cells and nerve plexuses were stained for substance P-like immunoreactivity by the peroxidaseantiperoxidase method. Substance P-like nerve fibres are present as pericellular baskets around most, but not all, of the neuronal cell bodies, and are also found in the connecting nerve bundles, as perivascular nerve plexuses and in the myocardium and pericardium. The majority of ganglion cell bodies are negative for substance P, as reported previously, but we describe for the first time, a small subpopulation of intrinsic neuronal cell bodies which show immunoreactivity for substance P. Therefore, not all cardiac substance P nerves are extrinsic afferent fibres. At present, the physiological role of intrinsic substance P neurones is not clear.