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H Penzlin

Publications and source records attributed to H Penzlin.

35 records · Page 2Linked to original sources
PubMed1989

Evidence for a myotropic effect of substance P in Periplaneta americana L.

It is shown that the isolated oviduct as well as the proctodeum of the cockroach Periplaneta americana are sensitive to substance P application. In contrast, the hyperneural muscle and the dilator muscle of the antennal heart were insensitive to this neuropeptide. The entire substance P amino acid sequence is necessary for the effects. This provides evidence for a pharmacological effect of substance P in insects.

Animals↗
PubMed1988

Morphology of neurones associated with the antennal heart of Periplaneta americana (Blattodea, Insecta).

Innervation of the antennal heart, an independent accessory circulatory motor in the head of insects, was investigated in the cockroach Periplaneta americana by use of axonal cobalt filling and transmission electron microscopy. The muscles associated with this organ are innervated by neurones located in a part of the suboesophageal ganglion, generally considered to be formed by the mandibular neuromere. Dorsal unpaired median (DUM) and paired contralateral neurones were stained. The axons of all these neurones run along the circumoesophageal connectives and through the paired nervus corporis cardiaci III into the corpora cardiaca. They pass through these organs forming fine arborizations there and exit anteriorly as a small pair of nerves which terminate at the antennal heart-dilator muscles. Numerous branches of these nerves extend beyond the lateral borders of the large transverse dilator muscle and terminate in the ampullar walls of the antennal heart. These neurosecretory fibres form neurohaemal areas which obviously release their products into the haemolymph, which is pumped into the antennae. The possible functions of the neurones associated with the antennal heart are discussed with respect to both, their role as a modulatory input for the circulatory motor and as a neurohormonal release site.

Animals↗
PubMed1988

Simultaneous localization of a classical neurotransmitter (GABA) and a peptide transmitter candidate (proctolin) in the nervous system of the cockroach, Periplaneta americana.

The distribution of the neurotransmitter gamma-aminobutyric acid (GABA) in the 6th abdominal ganglion of the cockroach Periplaneta americana was investigated using an antiserum against GABA. The high number of GABA immunoreactive neurons refer to the important function of this transmitter substance. The relation between the GABAergic system and the proctolinergic system in the 6th abdominal ganglion was examined by means of an immunohistochemical double staining technique. The results show that probably GABA and proctolin do not coexist within one neuron.

Animals↗
PubMed1987

A comparative study of the immunohistochemical localization of a presumptive proctolin-like peptide, thyrotropin-releasing hormone and 5-hydroxytryptamine in the rat central nervous system.

A proctolin (PROC)-like peptide was studied immunohistochemically in the hypothalamus, lower brainstem and spinal cord of the rat using an antiserum against PROC conjugated to thyroglobulin. Neuronal cell bodies containing PROC-like immunoreactivity (PROC-LI) were observed in the dorsomedial, paraventricular and supraoptic nuclei of the hypothalamus and in the nucleus raphe magnus, nucleus raphe pallidus, nucleus raphe obscurus and nucleus interfascicularis nervi hypoglossi in the medulla oblongata. Fibers containing PROC-LI were seen in the median eminence and in other hypothalamic nuclei, and in the lower brainstem in cranial motor nuclei including the dorsal motor nucleus of the vagus nerve, the motor trigeminal nucleus, the facial nucleus and nucleus ambiguous, and in lower numbers in the nucleus of the solitary tract and locus coeruleus. Fibers containing PROC-LI were also located in the spinal cord, in the intermediolateral cell column at thoracic levels and in the ventral horns at all levels of the spinal cord. After transection of the spinal cord, all PROC-immunoreactive fibers below the lesion disappeared. Following injection of Fast blue into the thoracic spinal cord, retrogradely labeled cells in the nuclei raphe pallidus, obscurus and magnus and nucleus interfasciculari nervi hypoglossi were seen to contain PROC-LI. PROC-LI had a similar distribution as thyrotropin-releasing hormone (TRH)-LI in the above-mentioned areas and coexistence of TRH-LI and PROC-LI was shown in cell bodies in the hypothalamus and medulla oblongata. PROC-LI could also be shown to coexist with 5-hydroxytryptamine (5-HT)-LI in neuronal cell bodies in the lower brainstem. The results demonstrate the occurrence of a PROC-like peptide in the mammalian nervous system, and these neurons seem to be at least largely identical to previously described TRH systems. A possible involvement of the PROC-like peptide in spinal motor control is discussed in relation to the well-established role of PROC in control of motor behavior in insects and invertebrates.

Animals↗
PubMed1987

Effect of morphine and naloxone on shock avoidance learning in headless cockroaches (Periplaneta americana L.).

Systemic administration of high doses of morphine (56 micrograms morphine/g body weight) or of naloxone (54 micrograms naloxone/g body weight) results in a significant improvement of shock avoidance behavior in headless cockroaches. In both cases the learning parameter stimulation time (time during which an animal receives shocks) is significantly decreased. The behavioral parameters, stimulation rate (activity) and mean stimulation duration (shock responsiveness), as the two factors of the stimulation time considered individually, do not significantly change with morphine. Only the responses of both parameters together give the significant decrease of stimulation time (improvement of shock avoidance behavior) as mentioned above. However, the administration of naloxone causes a significant shortening of the mean stimulation duration indicating that these animals avoid the shocks by learning to lift their legs more quickly out of electrified saline in order to terminate the shocks (escape learning). Combined administration of both drugs together also causes a significant improvement of the leg-lifting response even at lower doses (morphine: 0.56 microgram plus naloxone: 0.54 microgram/g; morphine: 0.0056 microgram/g plus naloxone: 0.0054 microgram/g). Although the various effective doses of these drugs administered in combination have similar effects on the stimulation time, they affect the behavioral parameters in different ways. These different actions on activity and shock responsiveness as well as the efficacy of doses smaller than those known from vertebrates are discussed as behavioral evidence of opiate receptors in the cockroach.

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PubMed1986

Proctolin immunoreactive neurons in the human brain stem.

Using the peroxidase-antiperoxidase (PAP) technique it could be established that a variety of nerve cells of human Pons and Medulla oblongata contain proctolin-like material. These neurons belong to the Nuc. olivaris caudalis, Nuc. originis n. hypoglossi, Nuc. raphes dorsalis and the Nuc. ambiguus. Furthermore, proctolin immunoreactive peptide was found to be contained in certain fiber systems (Lemniscus medialis and fiber tracts near the Raphe).

Aging↗
PubMed1985

A comparison of shock avoidance learning in headless cockroaches in leg-lifting and lowering task.

Headless cockroaches were trained either to lift or to lower the prothoracic leg to avoid electric shocks. The learning process in both cases was very distinct. However, the learning performance in the lifting was better than in the lowering task. The reason for this poorer learning in the lowering task is due to the unconditioned leg raising movement of the animals to electric shocks. This unconditioned response affects the headless cockroaches avoid shocks in the lifting task by escape learning, whereas they avoid shocks in the lowering task by true avoidance learning. Injection of 30 microliter of Ringer's solution has no significant effect on the learning process in the lifting task. In the lowering task, however, Ringer's solution impairs the learning ability considerably. Crude extract of corpora cardiaca strongly inhibits the learning of both tasks.

Animals↗
PubMed1985

The dependence of trout's electroretinographic response on temporal gradient of luminance. II. The off-response.

In this study trout's electroretinographic off-responses, elicited by ramp-like off-stimuli of variable decay time were recorded and evaluated. In the off-response of the trout, at least two different subwaves could be separated. As the stimulus decay time was increased stepwise from 10 ms to 3000 ms, the earlier wave d1 showed a pronounced amplitude attenuation and only little increase of the peak time, while at the second, later wave d2 a less marked effect on the amplitude but a distinct increase of the peak time could be observed. Possible relations of the subwaves d1 and d2 to the photopic or the scotopic system, comparison with the on-response at similar stimulating conditions, and correlations with psychophysical findings are discussed. The parallels to the observations on mammals' ERG including the human being are demonstrated.

Animals↗
PubMed1984

Proctolin-related material in the mouse brain as revealed by immunohistochemistry.

By use of a specific antiserum against the insect peptide proctolin we were able to identify proctolin-immunoreactive neurons in the mouse brain. These nerve cells belong to the nuc. mesencephalicus n. trigemini. Furthermore, the antiserum stained very few nerve fibers with varicosities in the immediate neighborhood of the roof of the third ventricle. The chemical identity of the immunoreactive material with genuine proctolin remains to be elucidated.

Animals↗
PubMed1981

Immunocytochemical identification of proctolinlike immunoreactivity in the terminal ganglion and hindgut of the cockroach Periplaneta americana (L.).

In the American cockroach, the distribution and connections of neuronal elements of the terminal ganglion-proctodeal nerve-hindgut system were investigated by means of immunohistochemical methods and axonal CoCl2 iontophoresis. Proctolinlike immunoreactivity was localized within neurons of the terminal ganglion projecting into the proctodeal nerve on the one hand, and in nerve cells without a direct connection to this system on the other. Immunohistochemically, in whole mount preparations fibres of the proctodeal nerve and terminal structures in the hindgut musculature exhibit strong proctolinlike immunoreactivity. At the light- and electron-microscopic levels the pathways of about 30 somata of the proctodeal neural system were characterized by cobalt chloride iontophoresis. The relationships of cobalt filled and immunoreactive neuronal structures are discussed.

Animals↗
PubMed1981

The insect neuropeptide proctolin can affect the CNS and the smooth=muscle of mammals.

The insect neurotransmitter proctolin can affect different behavioural parameters in rats after intracerebroventricular administration. Proctolin decreased the horizontal exploratory activity and induced a long-lasting analgesia in a hot-plate test. Proctolin lenghthened the passive avoidance latency of rats after post-trial treatment and also in the pre-retention test situation. The self-stimulation rate of rats was significantly diminished after i.c.v. proctolin administration. Proctolin also induced in rat and mouse ileum in vitro a dose-dependent contraction of the gut smooth-muscle that can be blocked by atropine. The results show that an invertebrate neuropeptide (or its fragments) can also be active in mammals. The physiological relevance of the effects observed recently is unknown.

Animals↗
PubMed1980

Identification of neuronal pathways between the stomatogastric nervous system and the retrocerebral complex of the cockroach Periplaneta americana (L.).

The neuronal pathways connecting the stomatogastric nervous system with the retrocerebral complex of the cockroach, Periplaneta americana, were investigated by means of axonal cobalt chloride iontophoresis. Somata in the hypocerebral ganglion and in the nervus recurrens sending their axons to different parts of the stomatogastric nervous system were traced. Some axons in the oesophageal nerve arise from large perikarya in the anterior part of the pars intercerebralis and pass via the NCCI to the corpora cardiaca and the oesophageal nerve. The form a profuse dendritic tree in the protocerebrum. Fibers of the NCC I and NCC II as well as the NCA I and NCA II enter the stomatogastric nervous system via the hypocerebral ganglion.

Animals↗
PubMed1978

The neuronal connections of the frontal ganglion of the cockroach Periplaneta americana. A histological and iontophoretical study.

The frontal ganglion of the cockroach Periplaneta americana was studied histologically and its neuronal pathways were mapped by use of axonal cobalt iontophoresis. Neurons and fiber tracts of the frontal ganglion are directly linked with different regions of the central nervous system (tritocerebrum, protocerebrum, subesophageal ganglion) and with the more caudal parts of the stomatogastric nervous system (hypocerebral ganglion, nervus oesophagei).

Animals↗
PubMed1978

The frontal ganglion of Periplaneta americana L. (Insecta): an electron microscopic and immunohistochemical study.

The frontal ganglion, part of the stomatogastric nervous system, contains about 60 to 80 neurons, 25 to 30 micron in diameter. A well developed Golgi system, producing dense-core vesicles, lysosomes, multivesicular bodies and dense bodies are abundant. Glia elements are sparsely distributed. Many nerve fibres contain granules of different size and electron density. Five groups of fibres can be distinguished: Fibres with granules of about 200 nm (type A), fibres with granules of about 160 to 170 nm (type B), fibres with granules of about 80 to 100 nm (type C) and those with synaptic vesicles of 50 nm (type D) respectively. A fifth very small type contains neither vesicles nor granules. Special attention was paid to synaptic contacts. The divergent dyad seems to be the main type in the frontal ganglion. Frequently, neurosecretory endings are observed in presynaptic position. Immunocytochemical "staining" of neurosecretory material closely corresponds to the distribution of type A fibres, as observed electron microscopically. Immunoelectrophoresis of extracts from frontal ganglia with polyspecific anti-neurosecretion-serum reveals a single precipitation line, indicating that the immunocytochemical localization of neurosecretory material is due to reaction with a specific as well as a cross-reagent anitbody.

Animals↗
PubMedDate not supplied

Distribution of GABA-like immunoreactivity in the central nervous system of the cockroach, Periplaneta americana (L.).

Gamma-aminobutyric acid (GABA) is one of the most frequently occurring neurotransmitters in the central nervous system. Using an antiserum against a GABA-protein conjugate, this has also been demonstrated for insects. The distribution of GABA-like immunoreactive neuronal elements within the central nervous system of the insect Periplaneta americana has been investigated by means of immunocytochemistry. An overview of the distribution of neuronal elements with GABA-like immunoreactivity (GLIR) in the brain is given. The ventral nerve cord was extensively investigated. The highest number of neurons with GLIR was estimated in the metathoracic ganglion (ca. 1000). The function of the suboesophageal ganglion as an inhibitory centre for the central nervous system was further confirmed by the high number of GABAergic elements and descending GABAergic pathways within the ventral nerve cord. A GABAergic innervation of skeletal musculature by so-called common inhibitory neurons was revealed for the legs of cockroaches. Nevertheless, GABA mainly seems to be a neurotransmitter in central interneurons. Identical distribution patterns of neuronal elements after immunofluorescence double-staining with anti-GABA antibodies and antibodies against the GABA-synthesizing enzyme glutamic acid decarboxylase demonstrated the high specificity of the anti-GABA serum used in this paper.

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