Characterization of Oscillatory Olfactory Interneurones in the Protocerebrum of the Crayfish

1992 ◽  
Vol 167 (1) ◽  
pp. 15-38
Author(s):  
DEFOREST MELLON ◽  
DAVID C. SANDEMAN ◽  
RENATE E. SANDEMAN

1. We obtained intracellular electrophysiological recordings from local interneurones within the hemi-ellipsoid neuropile of the brain in the freshwater crayfish Cherax destructor and Procambarus clarkii. The recordings were made from perfused, isolated head preparations that provided several indications of a healthy physiological condition. 2. The hemi-ellipsoid interneurones are spontaneously active, generating bursts of action potentials at regular intervals. The inter-burst period differs among neurones, varying from about 1.0 s at the shortest periods to around 30 s for the longest periods. 3. Evidence from both electrophysiological recordings and from injection of Lucifer Yellow and Neurobiotin dyes into hemi-ellipsoid interneurones suggests that some of the cells in the populations are electrically coupled to one another. 4. Hemi-ellipsoid interneurones are driven postsynaptically by axons within the lateral protocerebral tract. Experiments with focal electrical stimulation strongly suggest that the pathways responsible include axons of the olfactory-globular tract. These findings support our previous electron microscopical data showing that olfactory-globular tract axons are presynaptic to the hemi-ellipsoid interneurones. 5. These findings support the conclusion that hemi-ellipsoid interneurones are an integral link in the central olfactory pathway of the crayfish. Note: Present address and address for reprint requests: Department of Biology, Gilmer Hall, University of Virginia, Charlottesville, VA 22901, USA.

Author(s):  
Alexandra J. White ◽  
Michael J. Northcutt ◽  
Suzanne E. Rohrback ◽  
Robert O. Carpenter ◽  
Margaret M. Niehaus-Sauter ◽  
...  

1999 ◽  
Vol 81 (3) ◽  
pp. 1231-1241 ◽  
Author(s):  
DeForest Mellon ◽  
Christopher J. Wheeler

Coherent oscillations in membrane potential synchronize impulse bursts in central olfactory neurons of the crayfish. Lateral protocerebral interneurons (LPIs) in the central olfactory pathway of the freshwater crayfish Procambarus clarkii reside within the lateral protocerebrum and receive direct input from projection neurons of the olfactory midbrain. The LPIs exhibit periodic (0.5 Hz) changes in membrane potential that are imposed on them synaptically. Acute surgical experiments indicate that the synaptic activity originates from a group of oscillatory neurons lying within the lateral protocerebrum. Simultaneous intracellular recordings from many LPI pairs indicate that this periodic synaptic input is synchronous and coherent among the population of ∼200 LPIs on each side of the brain. In many LPIs, specific odors applied to antennules in isolated head preparations generate long-lasting excitatory postsynaptic potentials and impulse bursts. The impulse bursts are generated only near the peaks of the ongoing depolarizations, ∼1 s after stimulus application, and so the periodic baseline activity is instrumental in timing burst generation. Simultaneous recordings from pairs of LPIs show that, when impulse bursts occur in both cells after an odorant stimulus, they are synchronized by the common periodic depolarizations. We conclude that the common, periodic activity in LPIs can synchronize impulse bursts in subsets of these neurons, possibly generating powerful long-lasting postsynaptic effects in downstream target neurons.


Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.


2019 ◽  
Vol 38 (2) ◽  
pp. 385 ◽  
Author(s):  
Marwa M. El-Naggar ◽  
Wael S. I. Abou-Elmagd ◽  
Ashraf Suloma ◽  
Hamza A. El-Shabaka ◽  
Magdy T. Khalil ◽  
...  

Author(s):  
Stefano Vassanelli

Establishing direct communication with the brain through physical interfaces is a fundamental strategy to investigate brain function. Starting with the patch-clamp technique in the seventies, neuroscience has moved from detailed characterization of ionic channels to the analysis of single neurons and, more recently, microcircuits in brain neuronal networks. Development of new biohybrid probes with electrodes for recording and stimulating neurons in the living animal is a natural consequence of this trend. The recent introduction of optogenetic stimulation and advanced high-resolution large-scale electrical recording approaches demonstrates this need. Brain implants for real-time neurophysiology are also opening new avenues for neuroprosthetics to restore brain function after injury or in neurological disorders. This chapter provides an overview on existing and emergent neurophysiology technologies with particular focus on those intended to interface neuronal microcircuits in vivo. Chemical, electrical, and optogenetic-based interfaces are presented, with an analysis of advantages and disadvantages of the different technical approaches.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marie-Hardy Laura ◽  
Cantaut-Belarif Yasmine ◽  
Pietton Raphaël ◽  
Slimani Lotfi ◽  
Pascal-Moussellard Hugues

AbstractCerebrospinal fluid (CSF) circulation relies on the beating of motile cilia projecting in the lumen of the brain and spinal cord cavities Mutations in genes involved in cilia motility disturb cerebrospinal fluid circulation and result in scoliosis-like deformities of the spine in juvenile zebrafish. However, these defects in spine alignment have not been validated with clinical criteria used to diagnose adolescent idiopathic scoliosis (AIS). The aim of this study was to describe, using orthopaedic criteria the spinal deformities of a zebrafish mutant model of AIS targeting a gene involved in cilia polarity and motility, cfap298tm304. The zebrafish mutant line cfap298tm304, exhibiting alteration of CSF flow due to defective cilia motility, was raised to the juvenile stage. The analysis of mutant animals was based on micro-computed tomography (micro-CT), which was conducted in a QUANTUM FX CALIPER, with a 59 µm-30 mm protocol. 63% of the cfap298tm304 zebrafish analyzed presented a three-dimensional deformity of the spine, that was evolutive during the juvenile phase, more frequent in females, with a right convexity, a rotational component and involving at least one dislocation. We confirm here that cfap298tm304 scoliotic individuals display a typical AIS phenotype, with orthopedic criteria mirroring patient’s diagnosis.


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