Neuroanatomy of the mesothoracic ganglion of the cockroach periplaneta americana (L.) II. Median neuron cell body groups

1984 ◽  
Vol 306 (1127) ◽  
pp. 191-218 ◽  
Keyword(s):  
Peripheral Nerves ◽  
Periplaneta Americana ◽  
Paraffin Sections ◽  
Additional Information ◽  
Neuron Cell Body ◽  
Show Evidence ◽  
Inhibitory Motoneuron ◽  
General Architecture ◽  
Dorsal Unpaired Median ◽  
General Appearance

The groups of neuron cell bodies in the midline of the mesothoracic ganglion of adult male Periplaneta americana (L.) were examined using Bodian silver-stained paraffin sections and toluidine blue-stained wholemounts to determine their general architecture, and axonal filling with Procion yellow or cobalt to study pathways of their neuron processes. Filling tracheae with trypan blue provided additional information on tracheation of the ganglion. Seven groups of somata were named according to position: the anterior m edian (AM), mid-dorsal median (MDM ), posterior dorsal median (PDM ), posterior median (PM ), anterior ventral median (AVM ), mid-ventral median (MVM ) and posterior ventral median (PVM ) groups. Each group is characterized by general appearance and position, numbers and sizes of constituent somata, and numbers and pathways of fibre bundles. Groups consist largely of interneurons, with a few efferent, presumed motor, neuron somata present in some. Different functional types of neurons (that is, motoneurons and interganglionic and intraganglionic interneurons) do not appear to be strictly segregated into different groups. The AM, PM , AVM and M VM groups contain apparently only interneurons, either interganglionic (AM), intraganglionic (PM, AVM ), or both together (M V M ). In the MDM group one motoneuron to each side supplies the dorsal root of peripheral nerve 2, four or five PDM cells (equivalent to dorsal unpaired median (DUM ) cells of other species) bifurcate to nerve 5 of both sides of the ganglion and some also branch to nerves 3, 4 and 6, and in the PVM group one cell to each side is the widespread common inhibitory motoneuron to nerves 3-6. Three other large, bifurcating neurons of the PDM group may be efferent but follow a somewhat different pathway and could not be traced into peripheral nerves. Numbers of somata in the seven groups total 200 or more, and intraganglionic interneurons seem greatly to outnumber interganglionic ones. The MDM , AVM , MVM and PVM groups show evidence of an apparently paired origin.

Discharge Patterns of Coxal Levator and Depressor Motoneurones of the Cockroach, Periplaneta Americana

1970 ◽  
Vol 52 (1) ◽  
pp. 139-165
Author(s):  
K. G. PEARSON ◽  
J. F. ILES
Keyword(s):  
Peripheral Nerves ◽  
Sensory Input ◽  
Periplaneta Americana ◽  
Motor Axon ◽  
Extracellular Recordings ◽  
Before And After ◽  
Collateral Pathways ◽  
Discharge Patterns ◽  
Flexion And Extension ◽  
Leg Movements

1. Observation of movements of the metathoracic legs of the cockroach before and after section of peripheral nerves allowed identification of muscles involved in flexion and extension of the femur. 2. Extracellular recordings from the nerves to these coxal muscles show that during rhythmic leg movements bursts of activity in a number of levator motor axons were strongly reciprocal and generally non-overlapping with those of a slow depressor motor axon. 3. These reciprocal patterns persisted after removal of all sensory input from the legs. 4. The durations of levator bursts were relatively constant compared to those of the depressor, corresponding to the behavioural observations on leg protraction time. The pattern was asymmetric: levator bursts could be generated without depressor activity, but never the reverse. 5. No evidence was found for inhibitory collateral pathways between antagonist motoneurones. 6. It is proposed that levator motoneurones are driven by a group of bursting interneurones which simultaneously inhibit the ongoing depressor activity.

scholarly journals The B[e] stars

1989 ◽  
Vol 113 ◽  
pp. 117-120
Author(s):  
F.-J. Zickgraf
Keyword(s):  
Physical Properties ◽  
Stellar Wind ◽  
Main Sequence ◽  
Massive Stars ◽  
High Mass ◽  
Sequence Evolution ◽  
Two Component ◽  
Show Evidence ◽  
High Mass Loss ◽  
General Appearance

AbstractB[e] supergiants show evidence for a non-spherical two-component stellar wind. The general appearance and the physical properties of the suggested disk-like configuration are discussed. The high mass-loss rates, the surprisingly large number and the location in the H-R diagram make these stars important for the understanding of the post-main-sequence evolution of massive stars.

scholarly journals Group personality during collective decision-making: a multi-level approach

2015 ◽  
Vol 282 (1802) ◽  
pp. 20142515 ◽  
Author(s):  
Isaac Planas-Sitjà ◽  
Jean-Louis Deneubourg ◽  
Céline Gibon ◽  
Grégory Sempo
Keyword(s):  
Decision Making ◽  
Personality Traits ◽  
Periplaneta Americana ◽  
Collective Decision ◽  
Future Research ◽  
Collective Decision Making ◽  
Social Feedback ◽  
Individual Personality ◽  
Show Evidence ◽  
Group Compositions

Collective decision-making processes emerge from social feedback networks within a group. Many studies on collective behaviour underestimate the role of individual personality and, as a result, personality is rarely analysed in the context of collective dynamics. Here, we show evidence of sheltering behaviour personality in a gregarious insect ( Periplaneta americana ), which is characterized by a collective personality at the group level. We also highlight that the individuals within groups exhibited consistent personality traits in their probability of sheltering and total time sheltered during the three trials over one week. Moreover, the group personality, which arises from the synergy between the distribution of behaviour profiles in the group and social amplifications, affected the sheltering dynamics. However, owing to its robustness, personality did not affect the group probability of reaching a consensus. Finally, to prove social interactions, we developed a new statistical method that will be helpful for future research on personality traits and group behaviour. This approach will help to identify the circumstances under which particular group compositions may improve the fitness of individuals in gregarious species.

Imidacloprid actions on insect neuronal acetylcholine receptors

1997 ◽  
Vol 200 (21) ◽  
pp. 2685-2692 ◽  
Author(s):  
S Buckingham ◽  
B Lapied ◽  
H Corronc ◽  
F Sattelle
Keyword(s):  
Nervous System ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Periplaneta Americana ◽  
Muscarinic Acetylcholine Receptors ◽  
Nicotinic Acetylcholine ◽  
Neonicotinoid Insecticide ◽  
Dose Dependent ◽  
Dorsal Unpaired Median ◽  
Giant Interneurone

The neonicotinoid insecticide Imidacloprid acts at three pharmacologically distinct acetylcholine receptor (AChR) subtypes in the cockroach (Periplaneta americana) nervous system, but is ineffective on muscarinic receptors. Imidacloprid (3-100µmoll-1) induced dose-dependent depolarizations at cockroach cercal afferent/giant interneurone synapses. These responses were insensitive to 20µmoll-1 atropine but were completely blocked by the nicotinic antagonist mecamylamine (50µmoll-1). Similarly, Imidacloprid-induced depolarizations of cultured cockroach dorsal unpaired median (DUM) neurones dissociated from the same (terminal abdominal) ganglion were also completely blocked by 100µmoll-1 mecamylamine. However, two components of the response could be distinguished on the basis of their differential sensitivities to 0.1µmoll-1-bungarotoxin (-BTX), which selectively blocks AChRs with 'mixed' nicotinic/muscarinic pharmacology in this preparation. This indicates that Imidacloprid affects both AChRs sensitive to -BTX and -BTX-insensitive nicotinic acetylcholine receptors (nAChRs). Thus, in the cockroach, Imidacloprid activates -BTX-sensitive synaptic nAChRs in giant interneurones, -BTX-insensitive extrasynaptic nAChRs in DUM neurones, and a recently characterized DUM neurone 'mixed' AChR that is sensitive to both nicotinic and muscarinic ligands. Imidacloprid does not act on muscarinic acetylcholine receptors (mAChRs) present on DUM neurone cell bodies and at the cercal afferent/giant interneurone synapses. This study shows that Imidacloprid can act on pharmacologically diverse nAChR subtypes.

Multiple Sites of Spike Initiation in a Bifurcating Locust Neurone

1978 ◽  
Vol 76 (1) ◽  
pp. 63-84 ◽  
Author(s):  
W. J. HEITLER ◽  
COREY S. GOODMAN
Keyword(s):  
Action Potential ◽  
Branch Point ◽  
Peripheral Nerves ◽  
Action Potentials ◽  
Room Temperature ◽  
Initiation Site ◽  
Left And Right ◽  
Axon Branch ◽  
Spike Initiation ◽  
Dorsal Unpaired Median

Recordings were made from the metathoracic dorsal unpaired median neurone to the extensor tibiae muscle (DUMETi) in the locust. This is a bifurcating neurone with axons exiting both sideS of the ganglion, whose soma can support a full action potential. Four different spike types were recorded in the soma, each of which we associate with a different region of the neurone. These were (1) a soma (S) spike of 70-90 mV, (2) a neurite (N) spike of 20-40 mV, occurring between the axon hillock and axon branch point, (3) and (4) axon (A) spikes of 8–15 mV, occurring distal to the branch point on the left and right axons. Each of these regions must therefore have its own spike initiation site. At spike frequencies greater than about 10 Hz at room temperature or 1-5 Hz at 32 °C (the preferred environmental temperature of the locust) the S-spike may fail, revealing A-spikes, or more rarely N-spikes. A-spikes usually consist of two more-or-less separate components, Al and Ar, which can be correlated with action potentials in the left and right axon branches by recording spikes extracellularly in the peripheral nerves on each side. Occasionally single component A-spikes occur when an action potential is initiated in only one axon, and fails to propagate across the branch point to the contralateral axon. Thus, action potentials may occur independently in the branches of this bifurcating neurone. After unilateral axotomy only S-spikes and N-spikes are recorded, indicating that action potentials no longer fail to propagate across the branch point. Anatomical asymmetries in the axon branches of DUMETi have been correlated with physiological asymmetries recorded in the soma of the same neurone.

Glial cells in peripheral nerves of the cockroach, Periplaneta americana

1988 ◽  
Vol 20 (5) ◽  
pp. 771-782 ◽  
Author(s):  
R.E. Blanco
Keyword(s):  
Glial Cells ◽  
Peripheral Nerves ◽  
Periplaneta Americana

COLORIMETRY OF HISTOLOGICAL MATERIAL

2020 ◽  
pp. 7-18
Author(s):  
Vadim A. Kozlov ◽  
Sergey P. Sapozhnikov
Keyword(s):  
Field Of View ◽  
Analysis Program ◽  
Experience Design ◽  
Color Analysis ◽  
Paraffin Sections ◽  
Additional Information ◽  
Software Products ◽  
Color Separation ◽  
Hematoxylin And Eosin ◽  
Histological Specimen

The relevance of the research lies in the use of conventional software products distributed under the GNU license to assess staining of histological material based on the analysis of photomicrographs. The purpose of the study is to demonstrate the opportunities of conventional software distributed under the GNU license, designed for color analysis of photos in histology to identify differences in tinctorial properties of tissues. The authors evaluated the opportunities of the Color Analysis program launched in the Android Nox Player 6.6.1.0 emulator (GNU license) under Windows 10 for color analysis of photomicrographs of various tissues histological sections. Photomicrographs of paraffin sections of 5 microns thick were obtained using a micro-microscope Mikmed-5 using a Levenhuk C800 NG 8M video eyepiece, USB 2.0. A white light lamp Feron G4 4000 K was used as an illuminator. In color analysis of photomicrographs stained with hematoxylin and eosin, or hematoxylin and Congo red, or by Unna, or by the designer three-color amyloid staining in the Color Analysis program, color separation patterns were obtained that reflect the relative area (%) of the field of view staining with shades characteristic for this method of staining. The authors formulate the standard conditions for the preparation of histological specimen and conditions for photographing micro-preparations to obtain comparable results in an experiment with the control-experience design. It is concluded that the program color analysis provides a significant amount of additional information about the histological material, which can be formalized and studied as statistical values.

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