scholarly journals Coherent Oscillations in Membrane Potential Synchronize Impulse Bursts in Central Olfactory Neurons of the Crayfish

1999 ◽  
Vol 81 (3) ◽  
pp. 1231-1241 ◽  
Author(s):  
DeForest Mellon ◽  
Christopher J. Wheeler
Keyword(s):  
Membrane Potential ◽  
Procambarus Clarkii ◽  
Synaptic Activity ◽  
Projection Neurons ◽  
Freshwater Crayfish ◽  
Olfactory Pathway ◽  
Olfactory Neurons ◽  
Baseline Activity ◽  
The Common ◽  
Lateral Protocerebrum

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.

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
Keyword(s):  
Procambarus Clarkii ◽  
Lucifer Yellow ◽  
Freshwater Crayfish ◽  
University Of Virginia ◽  
Olfactory Pathway ◽  
Electrophysiological Recordings ◽  
Burst Period ◽  
Electron Microscopical ◽  
The Brain

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.

scholarly journals Mapping Membrane Potential Transients in Crayfish (Procambarus clarkii) Optic Lobe Neuropils With Voltage-Sensitive Dyes

1999 ◽  
Vol 81 (1) ◽  
pp. 334-344 ◽  
Author(s):  
Sergey Yagodin ◽  
Carlos Collin ◽  
Daniel L. Alkon ◽  
Norman F. Sheppard ◽  
David B. Sattelle
Keyword(s):  
Membrane Potential ◽  
Visual Information ◽  
Action Potentials ◽  
Optic Lobe ◽  
Procambarus Clarkii ◽  
Projection Neurons ◽  
Medulla Terminalis ◽  
Voltage Sensitive Dyes ◽  
Hemiellipsoid Body ◽  
Synaptic Responses

Yagodin, Sergey, Carlos Collin, Daniel L. Alkon, Norman F. Sheppard, Jr., and David B. Sattelle. Mapping membrane potential transients in crayfish ( Procambarus clarkii) optic lobe neuropils with voltage-sensitive dyes. J. Neurophysiol. 81: 334–344, 1999. Voltage-sensitive dyes NK 2761 and RH 155 were employed (in conjunction with a 12 × 12 photodiode array) to study membrane potential transients in optic lobe neuropils in the eye stalk of the crayfish Procambarus clarkii. By this means we investigated a pathway linking deutocerebral projection neurons, via hemiellipsoid body local interneurons, to an unidentified target (most likely neurons processing visual information) in the medulla terminalis. Rapid (10- to 20-ms duration), transient changes in absorption with the characteristics of action potentials were recorded from the optic nerve and the region occupied by deutocerebral projection neurons after stimulation of the olfactory globular tract in the optic nerve and were blocked by 1 μM tetrodotoxin. Action potentials appeared to propagate to the glomerular layer of the hemiellipsoid body where synaptic responses were recorded from a restricted region of the hemiellipsoid body occupied by dendrites of hemiellipsoid body neurons. Action potentials were also recorded from processes of hemiellipsoid body neurons located in the medulla terminalis. Synaptic responses in the hemiellipsoid body and medulla terminalis were eliminated by addition to the saline of 500 μM Cd2+ or 20 mM Co2+, whereas the action potential attributed to branches of deutocerebral projection neurons in the hemiellipsoid body remained unaffected. Action potentials of hemiellipsoid body neurons in the medulla terminalis evoked postsynaptic potentials (50- to 200-ms duration) with an unidentified target in the medulla terminalis. Transient absorption signals were not detected in either the internal or external medulla nor were they recorded from other parts of the optic lobes in response to electrical stimulation of axons of the deutocerebral projection neurons. Functional maps of optical activity, together with electrophysiological and pharmacological findings, suggest that γ-aminobutyric acid affects synaptic transmission in glomeruli of the hemiellipsoid body. Synapses of the olfactory pathway located in the medulla terminalis may act as a “filter,” modifying visual information processing during olfactory stimulation.

Convergence of Multimodal Sensory Input Onto Higher-Level Neurons of the Crayfish Olfactory Pathway

2000 ◽  
Vol 84 (6) ◽  
pp. 3043-3055 ◽  
Author(s):  
DeForest Mellon
Keyword(s):  
Compound Eye ◽  
Sensory Information ◽  
Afferent Input ◽  
Oscillatory Activity ◽  
Projection Neurons ◽  
Olfactory Lobe ◽  
Olfactory Pathway ◽  
Accessory Lobe ◽  
Lateral Protocerebrum ◽  
Stimulation Of

Intracellular electrophysiological studies of lateral protocerebral interneurons (LPIs) in the crayfish Procambarus clarkii have revealed convergence of multimodal sensory information onto these higher-level cells of the crustacean central olfactory pathway. Antennular stimulation by odors or electrical shocks generates excitatory-inhibitory sequences in some LPIs as does electrical or hydrodynamic stimulation of the antennae. Photic stimulation of the ipsilateral compound eye generates excitatory responses in LPIs, usually in the form of trains of impulse bursts that are timed to the peaks of the spontaneous oscillatory activity that characterizes these neurons. Focal electrical stimulation of the olfactory lobe, the termination point of antennular afferent input, or the accessory lobe, where higher-level visual and tactile inputs converge, also generates brief excitation and a delayed, prolonged inhibition in LPIs. Both phases of this activity are thought to be transmitted to the lateral protocerebrum via deutocerebral projection neurons, which have extensive dendritic arborizations in the olfactory lobe and the accessory lobe. The excitatory pathway is thought to synapse directly with target LPIs, whereas the inhibitory pathway is probably indirect and mediated through GABAergic interneurons within the lateral protocerebrum. There is evidence that both presynaptic and postsynaptic inhibition suppress activity in LPIs. Preliminary observations suggest that a small cluster of neurons adjacent to the hemi-ellipsoid body are inhibitory to LPI activity. Multimodal inhibitory and excitatory modulation of LPI activity may play a part in the contextual identification of odors in the crayfish olfactory system.

scholarly journals Morphology and physiology of olfactory neurons in the lateral protocerebrum of the silkmoth Bombyx mori

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shigehiro Namiki ◽  
Ryohei Kanzaki
Keyword(s):  
Bombyx Mori ◽  
Projection Neurons ◽  
Suitable Model ◽  
Olfactory Neurons ◽  
Delta Area ◽  
Output Neurons ◽  
Plant Odours ◽  
Mushroom Body Calyx ◽  
The Brain ◽  
Lateral Protocerebrum

Abstract Insect olfaction is a suitable model to investigate sensory processing in the brain. Olfactory information is first processed in the antennal lobe and is then conveyed to two second-order centres—the mushroom body calyx and the lateral protocerebrum. Projection neurons processing sex pheromones and plant odours supply the delta area of the inferior lateral protocerebrum (∆ILPC) and lateral horn (LH), respectively. Here, we investigated the neurons arising from these regions in the brain of the silkmoth, Bombyx mori, using mass staining and intracellular recording with a sharp glass microelectrode. The output neurons from the ∆ILPC projected to the superior medial protocerebrum, whereas those from the LH projected to the superior lateral protocerebrum. The dendritic innervations of output neurons from the ∆ILPC formed a subdivision in the ∆ILPC. We discuss pathways for odour processing in higher order centres.

Coincident Stimulation With Pheromone Components Improves Temporal Pattern Resolution in Central Olfactory Neurons

1997 ◽  
Vol 77 (2) ◽  
pp. 775-781 ◽  
Author(s):  
Thomas A. Christensen ◽  
John G. Hildebrand
Keyword(s):  
Stimulus Duration ◽  
Strong Correlation ◽  
Temporal Pattern ◽  
Pheromone Component ◽  
Projection Neurons ◽  
Inhibitory Input ◽  
Olfactory Neurons ◽  
Essential Component ◽  
Pheromone Components ◽  
Pattern Resolution

Christensen, Thomas A. and John G. Hildebrand. Coincident stimulation with pheromone components improves temporal pattern resolution in central olfactory neurons. J. Neurophysiol. 77: 775–781, 1997. Male moths must detect and resolve temporal discontinuities in the sex pheromonal odor signal emitted by a conspecific female moth to orient to and locate the odor source. We asked how sensory information about two key components of the pheromone influences the ability of certain sexually dimorphic projection (output) neurons in the primary olfactory center of the male moth's brain to encode the frequency and duration of discrete pulses of pheromone blends. Most of the male-specific projection neurons examined gave mixed postsynaptic responses, consisting of an early suppressive phase followed by activation of firing, to stimulation of the ipsilateral antenna with a blend of the two behaviorally essential pheromone components. Of 39 neurons tested, 33 were excited by the principal (most abundant) pheromone component but inhibited by another, less abundant but nevertheless essential component of the blend. We tested the ability of each neuron to encode intermittent pheromonal stimuli by delivering trains of 50-ms pulses of the two-component blend at progressively higher rates from 1 to 10 per second. There was a strong correlation between 1) the amplitude of the early inhibitory postsynaptic potential evoked by the second pheromone component and 2) the maximal rate of odor pulses that neuron could resolve ( r = 0.92). Projection neurons receiving stronger inhibitory input encoded the temporal pattern of the stimulus with higher fidelity. With the principal, excitatory component of the pheromone alone as the stimulus, the dynamic range for encoding stimulus intermittency was reduced in nearly 60% of the neurons tested. The greatest reductions were observed in those neurons that could be shown to receive the strongest inhibitory input from the second behaviorally essential component of the blend. We also tested the ability of these neurons to encode stimulus duration. Again there was a strong correlation between the strength of the inhibitory input to a neuron mediated by the second pheromone component and that neuron's ability to encode stimulus duration. Neurons that were strongly inhibited by the second component could accurately encode pulses of the blend from 50 to 500 ms in duration ( r = 0.94), but that ability was reduced in neurons receiving little or no inhibitory input ( r = 0.23). This study confirms that certain olfactory projection neurons respond optimally to a particular odor blend rather than to the individual components of the blend. The key components activate opposing synaptic inputs that enable this subset of central neurons to copy the duration and frequency of intermittent odor pulses that are a fundamental feature of airborne olfactory stimuli.

Iinfectious hypodermal and haematopoietic necrosis virus (IHHNV) infection in freshwater crayfish Procambarus clarkii

Aquaculture ◽  
2017 ◽  
Vol 477 ◽  
pp. 76-79 ◽  
Author(s):  
Bo-Kun Chen ◽  
Zhen Dong ◽  
Da-Peng Liu ◽  
Yong-Bin Yan ◽  
Neng-Yuan Pang ◽  
...  
Keyword(s):  
Procambarus Clarkii ◽  
Freshwater Crayfish ◽  
Necrosis Virus

scholarly journals Membrane Potential Dynamics of Neocortical Projection Neurons Driving Target-Specific Signals

Neuron ◽  
2013 ◽  
Vol 80 (6) ◽  
pp. 1477-1490 ◽  
Author(s):  
Takayuki Yamashita ◽  
Aurélie Pala ◽  
Leticia Pedrido ◽  
Yves Kremer ◽  
Egbert Welker ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Projection Neurons

Synaptic and intrinsic control of membrane excitability of neostriatal neurons. II. An in vitro analysis

1990 ◽  
Vol 63 (4) ◽  
pp. 663-675 ◽  
Author(s):  
P. Calabresi ◽  
N. B. Mercuri ◽  
G. Bernardi
Keyword(s):  
Membrane Potential ◽  
Tetanus Toxin ◽  
Reversal Potential ◽  
Membrane Potentials ◽  
Synaptic Activity ◽  
Membrane Properties ◽  
Membrane Excitability ◽  
Epsp Amplitude ◽  
The Relationship

1. The effects of intrinsic membrane properties on the spontaneous and synaptically evoked activity of neostriatal neurons were studied in an in vitro slice preparation with the use of intracellular recordings. The recorded neurons did not show spontaneous action potentials at rest; depolarizing current pulses triggered a tonic firing pattern. 2. Subthreshold spontaneous depolarizing potentials (SDPs) were observed in 52% of the recorded neurons. The amplitude of these potentials at rest ranged between 2 and 15 mV, and their duration between 4 and 100 ms. The frequency and the amplitude of the SDPs were functions of the membrane potential: membrane depolarization by constant positive current increased the frequency of the SDPs and reduced their amplitude; hyperpolarization of the membrane decreased their frequency and increased their amplitude. Often, at membrane potentials more negative than -90 mV, SDPs were completely suppressed. 3. SDPs were blocked by low calcium-cobalt containing solutions. In the presence of tetrodotoxin (TTX, 1-3 microM), SDPs were completely abolished in 50% of the tested neurons; in the remaining neurons, small (1-4 mV) TTX-resistant SDPs were observed. In most of the neurons, bicuculline (BIC, 10-100 microM) and low concentrations of tetanus toxin (5-10 micrograms/ml) did not clearly affect the SDPs. Higher concentrations of tetanus toxin (100 micrograms/ml) blocked the SDPs as well as the synaptic potentials evoked by intrastriatal stimulation. 4. At resting membrane potential, intrastriatal stimulation produced a fast depolarizing postsynaptic potential (EPSP) that was reduced by BIC (10-100 microM). The relationship between EPSP amplitude and membrane potential was studied either by utilizing K(+)-chloride electrodes or by the use of cesium-chloride electrodes. In both these cases, the reversal potential for the EPSPs was between 0 and -14 mV. In cesium-loaded neurons, the decrease of the EPSP, usually observed at negative membrane potentials (below -85 mV), was clearly reduced. Internal cesium prolonged the duration of the SDPs and the EPSPs evoked by intrastriatal stimulation. 5. The relationship between spontaneous and evoked synaptic activity and membrane potential was studied in the presence of different external potassium blockers. 4-Aminopyridine (4AP, 0.1-1 mM) increased the EPSP amplitude and the frequency of the SDPs, but did not decrease membrane rectification and the shunt of the EPSPs present at negative membrane potentials. On the contrary, rectification of the membrane and the shunt of the EPSPs below -85 mV were clearly reduced by tetraethylammonium (TEA, 10-20 mM).(ABSTRACT TRUNCATED AT 400 WORDS)

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