scholarly journals Morphology and intracellularly recorded action potentials of crustacean X-organ-sinus gland systems stained with Lucifer yellow.

1985 ◽  
Vol 61 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Misako NAGANO
Keyword(s):  
Action Potentials ◽  
Lucifer Yellow ◽  
Sinus Gland

Electrical properties and innervation of fibers in the orbital layer of rat extraocular muscles

1989 ◽  
Vol 61 (1) ◽  
pp. 116-125 ◽  
Author(s):  
J. Jacoby ◽  
D. J. Chiarandini ◽  
E. Stefani
Keyword(s):  
Electrical Properties ◽  
Nerve Stimulation ◽  
Action Potentials ◽  
Time Course ◽  
Lucifer Yellow ◽  
Extraocular Muscles ◽  
Resting Potential ◽  
Inferior Rectus ◽  
End Plate ◽  
Orbital Layer

1. The inferior rectus muscle of rat, one of the extraocular muscles, contains two populations of multiply innervated fibers (MIFs): orbital MIFs, located in the orbital layer of the muscle and global MIFs, found in the global layer. The electrical properties and the responses to nerve stimulation of orbital MIFs were studied with single intracellular electrodes and compared with those of twitch fibers of the orbital layer, MIFs of the global layer, and tonic fibers of the frog. 2. About 90% of the orbital MIFs did not produce overshooting action potentials. In these fibers the characteristics and time course of the responses to nerve stimulation varied along the length of the fibers. Within 2 mm of the end-plate band of the muscle, the responses consisted of several small end-plate potentials (EPPs) and a nonovershooting spike. Distal to 2 mm, the responses in most fibers consisted of large and small EPPs with no spiking response. Some fibers produced very small spikes surmounted on large EPPs. 3. Overshooting action potentials were observed in approximately 10% of the orbital MIFs recorded between the end-plate band and 2 mm distal. The presence or absence of action potentials was not related to the magnitude of the resting potential of the fibers. 4. The threshold of nerve stimulated responses in orbital MIFs was the same as that in orbital twitch fibers. A large number of orbital MIFs had latencies equal to those for the orbital twitch fibers recorded at the same distance from the end-plate band, but the average latency was greater in the MIFs. The latency of orbital MIFs was about one-half of that for the MIFs of the global layer. The values for the effective resistance and membrane time constant of orbital MIFs fell between those for orbital twitch fibers on the one hand, and global MIFs and frog tonic fibers on the other. 5. In order to compare electrical properties with innervation patterns, fibers identified electrophysiologically as orbital MIFs were injected with the fluorescent dye Lucifer yellow and then traced in Epon-embedded, serial transverse sections. In addition to numerous superficial endings distributed along the fibers, a single "en plaque" ending was also found in the end-plate band that resembled the end plates of the adjacent orbital twitch fibers. 6. From these results we conclude that the electrical activity of orbital MIFs varies along the length of the fibers.(ABSTRACT TRUNCATED AT 400 WORDS)

Identification of a putative mechanosensory neuron in Lymnaea: characterization of its synaptic and functional connections with the whole-body withdrawal interneuron

1996 ◽  
Vol 76 (5) ◽  
pp. 3230-3238 ◽  
Author(s):  
T. Inoue ◽  
M. Takasaki ◽  
K. Lukowiak ◽  
N. I. Syed
Keyword(s):  
Sensory Neuron ◽  
Action Potentials ◽  
Synaptic Connection ◽  
Lucifer Yellow ◽  
Whole Body ◽  
Pond Snail ◽  
Mechanosensory Neuron ◽  
Functional Connections ◽  
Freshwater Pond ◽  
Withdrawal Behavior

1. In this study, we identified a putative mechanosensory neuron in the freshwater pond snail Lymnaea stagnalis. This sensory neuron, termed right parietal dorsal 3 (RPD3), mediates part of the whole-body withdrawal behavior via the activation of a withdrawal interneuron. 2. RPD3 is located in the central ring ganglia, where its soma is situated on the dorsal surface of the right parietal ganglion. Intracellular injection of the dye Lucifer yellow revealed that RPD3 has both central and peripheral axonal projections. 3. In isolated-CNS preparations, RPD3 was quiescent. In semi-intact preparations, however, a gentle/moderate mechanical touch (by a pair of blunt forceps) to the mantle cavity or columellar musculature elicited action potentials in RPD3 in the absence of prepotential activity. Furthermore, mechanical stimulus-induced action potentials in RPD3 persisted in the presence of zero Ca2+/ high Mg2+ and high Ca2+/high Mg2+ salines. Together, these data suggest that RPD3 is most likely to be a primary sensory neuron. 4. In both isolated-CNS and semi-intact preparations, intracellular depolarization of RPD3 excited the whole-body withdrawal interneuron right pedal dorsal 11 (RPeD11). This synaptic connection persisted in the presence of high Ca2+ and high Mg2+ saline, suggesting that it is likely to be monosynaptic. Moreover, when stimulated electrically, the interneuron RPeD11 induced an hyperpolarizing response in RPD3. The possibility of this connection being monosynaptic was not tested, however, in the present study. Together, these data demonstrate that RPD3 excites RPeD11, which in turn may inhibit RPD3 activity. 5. In the semi-intact preparation, a mechanical touch to the mantle edge excited RPD3, which in turn generated action potentials in RPeD11. Zero Ca2+ saline blocked this synaptic connection between RPD3 and RPeD11, suggesting that it is chemical. 6. To demonstrate that RPD3 was sufficient to induce the withdrawal response and that the withdrawal behavior was mediated indirectly via RPeD11, we made simultaneous intracellular recordings from these two neurons while monitoring muscle contractions via a tension transducer. Intracellular depolarization of RPD3 elicited action potentials in RPeD11, followed by the contraction of the columellar muscle. Similar stimulation of RPD3 failed to excite a simultaneously hyperpolarized RPeD11 and as a result, no contraction of the columellar muscle occurred. Direct intracellular depolarization of RPeD11, however, induced the contraction of the columellar muscle. These data suggest that RPD3-induced withdrawal behavior is mediated in part via RPeD11.

Intracellular characterization of identified sensory cells in a new spider mechanoreceptor preparation

1994 ◽  
Vol 71 (4) ◽  
pp. 1422-1427 ◽  
Author(s):  
E. A. Seyfarth ◽  
A. S. French
Keyword(s):  
Sensory Neurons ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Sense Organ ◽  
Sensory Cells ◽  
Cupiennius Salei ◽  
Bursting Neuron ◽  
Sensory Structures ◽  
Spider Cupiennius Salei

1. We have developed an isolated mechanoreceptor-organ preparation in which the intact sensory structures are available for mechanical stimulation and electrical recording. The anterior lyriform slit sense organ on the patella of the spider, Cupiennius salei Keys., consists of seven or eight cuticular slits, each innervated by a pair of large bipolar sensory neurons. The neurons are fusiform, and the largest somata are < or = 120 microns long. The innervation of the organ was characterized by light microscopy of neurons backfilled with neuronal tracers. Intracellular recording was used to measure the passive and active electrical properties of the neurons, in several cases followed by identification with Lucifer yellow injection. Both neurons of each pair from one slit responded with action potentials to depolarization by a step current injection. Approximately half of the sensory neurons adapted very rapidly and generated only one or two action potentials in response to a sustained depolarizing step, while a second group produced a burst of action potentials that adapted to silence in approximately 1 s or less. Recordings from identified neuron pairs indicated that each pair consists of one rapidly adapting and one bursting neuron. Measurements of cell membrane impedances and time constants produced estimates of neuronal size that agreed with the morphological measurements. This new preparation offers the possibility of characterizing the mechanisms underlying transduction and adaptation in primary mechanosensory neurons.

Electrical Activity and Structure of Retinal Cells of the Aplysia Eye: I. Secondary Neurones

1982 ◽  
Vol 99 (1) ◽  
pp. 369-380
Author(s):  
JON W. JACKLET ◽  
LESLEY SCHUSTER ◽  
CELINE ROLERSON
Keyword(s):  
Optic Nerve ◽  
Electrical Activity ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Antidromic Activation ◽  
Retinal Cells ◽  
Compound Action Potentials ◽  
Pacemaker Potentials ◽  
Evoked Activity ◽  
Chemical Synapses

1. Intracellular recordings were made from secondary neurones and photo-receptors of the Aplysia eye concurrently with extracellular recordings from the optic nerve. These cells were injected with Lucifer yellow to reveal their structure after they were typed according to electrical activity. Secondary neurones are described in this paper. 2. All secondary neurones injected with Lucifer yellow were in the outer, non-receptor layer of the retina. Each had an axon in the optic nerve, short dendritic processes on the soma, but no distinct photoreceptive apparatus. Dye coupling between secondary neurones and between secondary neurones and photoreceptors was observed. 3. Secondary neurones had pacemaker potentials and action potentials (APs) correlated 1:1 with the optic nerve compound action potentials (CAPs) during spontaneous dark and light evoked activity. It is deduced that the secondary neurones are the output neurones of the circadian clock system of the eye. 4. Secondary neurones appear to be electrically coupled to each other and to some photoreceptors, since blocking chemical synapses with high Mg2+ saline did not block the spontaneous or light evoked activities, and antidromic activation of the secondary neurones produced a compound input dependent in amplitude on stimulus voltage. 5. Backfilling the optic nerve with cobalt revealed filled secondary neurones, 2 photoreceptor types and a small non-receptor cell type suggesting that most of these retinal cells have axons in the optic nerve.

Architecture of Cerebral Neurosecretory Cell Systems in the Silkworm Bombyx Mori

1991 ◽  
Vol 161 (1) ◽  
pp. 217-237
Author(s):  
TOSHIO ICHIKAWA
Keyword(s):  
Bombyx Mori ◽  
Nerve Cord ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Cell Group ◽  
Neurosecretory Material ◽  
Larval Brain ◽  
Dendritic Branches

Anatomical and physiological characteristics of putative neurosecretory cells (NSCs) in the medial and lateral areas of the larval brain of Bombyx mori, identifiable by the opalescent appearance of their somata, were examined by means of intracellular recording and staining. Intracellular injection of Lucifer Yellow revealed that the medial cell group consisted of at least six subgroups of cells distinguishable by the geometry of their dendritic branches. Five subgroups of cells project axons to the contralateral corpus allatum (CA) or to the corpus cardiacum (CC). The remaining subgroup sends an axon to the ipsilateral ventral nerve cord. Three subgroups of cells were identified in the lateral group, projecting axons to the ipsilateral CC, to the CA or to the contralateral CA. Large and prolonged action potentials, similar to those recorded in some neurosecretory systems, were recorded from these medial and lateral cells. However, two pairs of medial cells containing paraldehyde-fuchsin-positive (neurosecretory) material and with axons extending to the contralateral nerve cord had action potentials of a short duration, more typical of non-NSCs such as tritocerebral cells innervating the stomodeal dilator muscles via the CC.

Excitation and inhibition of the heart of the snail, Lymnaea, by non-FMRFamidergic motoneurons

1990 ◽  
Vol 63 (6) ◽  
pp. 1436-1447 ◽  
Author(s):  
K. J. Buckett ◽  
M. Peters ◽  
P. R. Benjamin
Keyword(s):  
Heart Muscle ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Constant Delay ◽  
Intracellular Injection ◽  
Neuronal Control ◽  
Fourth Class ◽  
Selective Antagonists ◽  
Chemical Synapses ◽  
Alpha Bungarotoxin

1. The present paper extends the model of neuronal control of the Lymnaea heart by the use of intracellular recording techniques to identify further types of cardioactive neurons in the CNS that, like the previously described E heart excitor (Ehe) cells, influence the myogenic heartbeat. 2. Four new types of neuron that act on the heart are described. These are excitatory Hhe and She cells (H and S heart excitors) and the inhibitory Khi cell (K heart inhibitor). The fourth class, tonus pericardium excitor (Tpe), modulates the heart by action on pericardial tissue. 3. Pharmacologic, electrophysiological, and anatomic evidence is presented that shows that these cells are motoneurons, innervating heart muscle fibers directly: blocking central chemical synapses failed to prevent the actions of the neurons on the heart; simultaneous intracellular recordings showed unitary EJPs in heart muscle after 1:1 and with constant delay from evoked neuronal action potentials; intracellular injection of the dye Lucifer yellow showed all cells had axonal branches entering the intestinal nerve (which innervates the heart). 4. The use of selective antagonists to 5-hydroxytryptamine (5-HT) (cinanserin), dopamine (ergonovine), and acetylcholine (alpha-bungarotoxin) provided evidence that the actions of She and Hhe cells are mediated by 5-HT, whereas those of the Khi cell are mediated by acetylcholine. 5. A cyclically active network of three interneuronal inputs acting on the heart motoneurons is described. 6. One of these, input 3, is responsible for periodic excitation of the heart via its effects on the Hhe cells.

Comparative electrophysiology of pyramidal and sparsely spiny stellate neurons of the neocortex

1985 ◽  
Vol 54 (4) ◽  
pp. 782-806 ◽  
Author(s):  
D. A. McCormick ◽  
B. W. Connors ◽  
J. W. Lighthall ◽  
D. A. Prince
Keyword(s):  
Action Potentials ◽  
Maximum Rate ◽  
Lucifer Yellow ◽  
Cell Types ◽  
Anterior Cingulate ◽  
Electrophysiological Properties ◽  
Physiological Properties ◽  
Fast Spiking ◽  
Tonic Current

Slices of sensorimotor and anterior cingulate cortex from guinea pigs were maintained in vitro and bathed in a normal physiological medium. Electrophysiological properties of neurons were assessed with intracellular recording techniques. Some neurons were identified morphologically by intracellular injection of the fluorescent dye Lucifer yellow CH. Three distinct neuronal classes of electrophysiological behavior were observed; these were termed regular spiking, bursting, and fast spiking. The physiological properties of neurons from sensorimotor and anterior cingulate areas did not differ significantly. Regular-spiking cells were characterized by action potentials with a mean duration of 0.80 ms at one-half amplitude, a ratio of maximum rate of spike rise to maximum rate of fall of 4.12, and a prominent afterhyperpolarization following a train of spikes. The primary slope of initial spike frequency versus injected current intensity was 241 Hz/nA. During prolonged suprathreshold current pulses the frequency of firing adapted strongly. When local synaptic pathways were activated, all cells were transiently excited and then strongly inhibited. Bursting cells were distinguished by their ability to generate endogenous, all-or-none bursts of three to five action potentials. Their properties were otherwise very similar to regular-spiking cells. The ability to generate a burst was eliminated when the membrane was depolarized to near the firing threshold with tonic current. By contrast, hyperpolarization of regular-spiking (i.e., nonbursting) cells did not uncover latent bursting tendencies. The action potentials of fast-spiking cells were much briefer (mean of 0.32 ms) than those of the other cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Radial Symmetry and the Organization of Central Neurones in a Hydrozoan Jellyfish

1984 ◽  
Vol 110 (1) ◽  
pp. 69-90 ◽  
Author(s):  
A. N. SPENCER ◽  
S. A. ARKETT
Keyword(s):  
Action Potentials ◽  
Functional Organization ◽  
Lucifer Yellow ◽  
Morphological Characteristics ◽  
Radial Symmetry ◽  
Nerve Ring ◽  
Rapid Reduction ◽  
Potential Oscillations ◽  
Polyorchis Penicillatus ◽  
Motor Neurones

1. Two discrete networks of neurones in the outer nerve-ring of Polyorchis penicillatus can be identified by their physiological and morphological characteristics. 2. The ‘B’ system is characterized by the regular, spontaneous firing pattern that can be recorded intracellularly. Bursts of up to six spikes are produced in response to a rapid reduction in the light intensity. 3. Neurones of the ‘B’ system are electrically coupled to one another. 4. Action potentials in the ‘B’ system produce unitary EPSPs in swimming motor neurones and in epithelial cells overlying the outer nerve-ring. 5. Lucifer Yellow injected into a ‘B’ neurone diffuses rapidly through neighbouring neurones to reveal a condensed network of neurones in the centre of the nerve-ring and a more diffuse network passing up and around each tentacle. 6. The ‘O’ system is characterized by very regular (approx. 1 Hz), spontaneous membrane potential oscillations. Action potentials are never recorded. 7. Neurones of the ‘O’ system are electrically coupled to one another. 8. There is evidence of interaction between the ‘O’ system and swimming motor neurones. 9. Lucifer Yellow injected into an ‘O’ neurone diffuses through member neurones to show an anastomosing network of neurones extending across the width of the outer nerve-ring and tracts of neurones extending up the sides of each tentacle towards the ocelli. 10. The restriction of injected Lucifer Yellow to each of the networks and the blockade of interaction between systems by Mg2+ anaesthesia are evidence that signalling between different central networks is by chemical means. 11. The adaptive advantages of this type of functional organization of central neurones in radially symmetrical animals are discussed. Such an organization is compared with that found in bilateral animals.

Diverse neuronal populations mediate local circuit excitation in area CA3 of developing hippocampus

1995 ◽  
Vol 74 (2) ◽  
pp. 650-672 ◽  
Author(s):  
K. L. Smith ◽  
D. H. Szarowski ◽  
J. N. Turner ◽  
J. W. Swann
Keyword(s):  
Confocal Microscopy ◽  
Gabaa Receptor ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Single Cells ◽  
Pyramidal Cells ◽  
Gamma Aminobutyric Acid ◽  
Gabaa Receptor Antagonist ◽  
Fast Spiking ◽  
Area Ca3

1. Studies were undertaken to better understand why the developing hippocampus has a marked capacity to generate prolonged synchronized discharges when exposed to gamma-aminobutyric acid-A (GABAA) receptor antagonists. 2. Excitatory synaptic interactions were studied in small microdissected segments of hippocampal area CA3. Slices were obtained from 10- to 16-day-old rats. Application of the GABAA receptor antagonist penicillin produced prolonged synchronized discharges in minislices that were very similar, if not identical, to those recorded in intact slices. The sizes of minislices were systematically varied. Greater than 90% of those that measured 600 microns along the cell body layer produced prolonged synchronized discharges, whereas most minislices measuring 300 microns produced only brief interictal spikes. 3. Action potentials in the majority (75%, 158 of 254) of cells impaled with microelectrodes were able to entrain the entire CA3 population. They were also able to increase (on average 26%) the frequency of spontaneous population discharges. The population discharges were followed by a refractory period that lasted 5–60 s, during which single cells were unable to initiate a population discharge. 4. The majority (87%) of neurons with intrinsic burst properties were found to entrain the CA3 population. The electrophysiological characteristics of these cells were reminiscent of recordings obtained from more mature rats. Action potentials were quite prolonged and demonstrated a secondary shoulder or hump on the down-slope of the spike. 5. When bursting cells were filled with Lucifer yellow and imaged during recording sessions by videomicroscopy and later using confocal microscopy, they showed the anatomic features of CA3 hippocampal pyramidal cells. Confocal microscopy permitted detailed characterization of individual neurons and showed substantial variation in cellular microanatomy. 6. Another class of cells that were found to entrain the CA3 population but did not demonstrate intrinsic bursts were termed regular-firing cells. These cells possessed many of the anatomic and physiological features of bursting cells with the exception of burst firing. They were rarely encountered in intracellular recordings. 7. The third physiological class of cells was termed fast-spiking cells. These had action potentials that were shorter in duration than the other two cell types. They were distinct in the rapid rate of spike repolarization. They demonstrated modest degrees of spike frequency adaptation and fired repeatedly and at relatively high frequencies. Compared with reports on fast-spiking cells in mature hippocampus and neocortex, action potentials appear to be slower and repetitive discharging appeared to be of a lower frequency.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Electrophysiological characterization of peptidergic neurosecretory terminals

1985 ◽  
Vol 118 (1) ◽  
pp. 1-35 ◽  
Author(s):  
I. M. Cooke
Keyword(s):  
Action Potentials ◽  
Repetitive Firing ◽  
Sinus Gland ◽  
Long Duration ◽  
Impulse Duration ◽  
Neurohaemal Organ ◽  
Cardisoma Guanhumi ◽  
Electrophysiological Characterization ◽  
Reduced Rate ◽  
Dye Marking

Electrical activity recorded intracellularly from peptidergic neurosecretory terminal dilatations in the sinus gland of crabs (principally Cardisoma guanhumi and C. carnifex) is described. Recordings were made from the neurohaemal organ in situ on the neural tissue of the isolated eyestalk and from isolated sinus gland-sinus gland nerve preparations. Verification that electrodes penetrated terminals was obtained by dye marking. Resting potentials ranged between −30 and −80mV. Overshooting action potentials of long duration (5–20 ms at 1/2 amplitude) relative to those of non-secretory axons (less than 2ms) were recorded in approximately 70% of stable penetrations. Action potentials occurred spontaneously at slow (less than 0.2s-1) rates in 75% of penetrations. Sequential intra- and extracellular recordings with the same microelectrode, on the same terminal, indicate impulse generation by the terminal itself. Extracellular stimulation of the axon tract evokes an all-or-none action potential at distinct threshold and latency. At rates of stimulation exceeding 5s-1, discrete fluctuations in the form of responses occur. Similar waveforms occur spontaneously and can be evoked by passing current through the electrode. They are interpreted to be electrotonically recorded activity of other parts of a complex axonal terminal arborization. Some, but not all, terminals exhibit impulse broadening (up to three-fold at 1/2 amplitude) during repetitive firing exceeding 1s-1. The same terminals show reduced impulse duration with hyperpolarization and broadened impulses with imposed depolarization. The changes are due to altered repolarization rates. Terminals sustain steady impulse firing at rates (up to 5s-1) linearly related to the imposed depolarizing current. Regenerative potentials, though of reduced rate of rise and amplitude, can be evoked by depolarizing current passed through the electrode during perfusion with salines having 1/2 normal [Na+], or containing tetrodotoxin (10(−6)moll-1). However, these block axonal conduction. Nominally Ca-free saline causes increased spontaneity and depolarization of about 5 mV in half the preparations examined, but reaching 20 mV in the others, with resultant inactivation of regenerative activity. Impulses in low-Ca saline show alterations of the falling phase, it being faster initially and then slower than normal. Thus, while the action potentials of neurosecretory axons are Na dependent, the terminals support regenerative impulses mediated by both Na and Ca.

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