Multiple, prolonged actions of neuroendocrine bag cells on neurons in Aplysia. I. Effects on bursting pacemaker neurons

1979 ◽  
Vol 42 (4) ◽  
pp. 1165-1184 ◽  
Author(s):  
E. Mayeri ◽  
P. Brownell ◽  
W. D. Branton ◽  
S. B. Simon
Keyword(s):  
Spike Activity ◽  
Ganglion Cells ◽  
Cell Activity ◽  
Egg Laying ◽  
Neuroendocrine Cells ◽  
Abdominal Ganglion ◽  
Normal Expression ◽  
The Central Nervous System ◽  
Bag Cells ◽  
Local Stimulation

1. The bag cells are a group of neuroendocrine cells located in the abdominal ganglion of Aplysia. Accumulated evidence suggests they synthesize and release egg-laying hormone (ELH), a peptide that induces egg laying. In this and the following paper (37) we describe five types of prolonged neural responses in cells of the isolated abdominal ganglion that are produced by stimulated bag cell activity. 2. Prolonged, 5- to 40-min bursts of spike activity were triggered in the normally silent bag cells by local stimulation of one of the bag cell clusters with brief, 0.6- to 2-strains of pulses. This local stimulation minimized the possible effects of the stimulus on other ganglion cells and initiated bag cell activity similar to what has been recorded in intact animals at the initiation of egg laying. 3. Following onset of triggered bag cell activity there is an increase in the amplitude of the bursting pacemaker potential in cell R15 that results in augmented bursting activity in this autoactive cell for up to 3 h. The increase begins in less than 1 min and reaches a maximim after 8--20 min. In two other bursting pacemaker cells, L3 and L6, there is a second type of response, slow inhibition, consisting of a smoothly graded hyperpolarization that begins in 5--14 s, reaches a peak value of 10--20 mV after 30 s, and results in a decrease in the spontaneous spike activity of these cells for 3 h or longer. Both types of responses are contingent on the occurrence of bag cell activity, they depend on prolonged bag cell activity for their normal expression, and they occur in the absence of the fast interactions characteristic of conventional synapses. 4. The results reveal at the level of intracellular recordings prolonged actions of peptide-secreting neuroendocrine cells on the central nervous system. The role of ELH as a putative mediator of one or more of these actions is discussed.

Multiple, prolonged actions of neuroendocrine bag cells on neurons in Aplysia. II. Effects on beating pacemaker and silent neurons

1979 ◽  
Vol 42 (4) ◽  
pp. 1185-1197 ◽  
Author(s):  
E. Mayeri ◽  
P. Brownell ◽  
W. D. Branton
Keyword(s):  
Spike Activity ◽  
Ganglion Cells ◽  
Direct Action ◽  
Neurosecretory Cells ◽  
Behavioral Pattern ◽  
Egg Laying ◽  
Large Numbers ◽  
The Central Nervous System ◽  
Bag Cells ◽  
Ganglion Neurons

1. A survey of identified cells of the abdominal ganglion of Aplysia was undertaken to determine the extent of bag cell influence in the ganglion. Bursts of bag cell spike activity lasting 5--40 min were elicited by brief, 0.6- to 2 s local stimulation while recording simultaneously from bag cells and other ganglion cells with intracellular electrodes. 2. Slow inhibition occurs in giant cell R2, neurosecretory cells R3-R14, and ink-gland motoneurons, L14A, B, C. The cells remain hyperpolarized for from 15 to 60 min. 3. Transient excitation occurs in mechanoreceptor cells L1 and R1. The cells are strongly depolarized by a slow excitatory potential that lasts for about 10 min and produces spike activity for 3--7 min. 4. Prolonged excitation occurs in some cells of the LB and LC identified cell clusters. The cells are depolarized and spike activity is increased for 3 h or more. 5. A biphasic response occasionally occurs in the command interneuron L10. Inhibition of this cell lasts 10--15 min and is followed by excitation for several hours. Excitation is accompanied by facilitation of synaptic potentials for 40--60 min in cells innervated by L10; the facilitation apparently results from the increase in L10 firing rate. 6. The results indicate that the bag cells have multiple types of actions and affect large numbers of ganglion neurons. All effects have the slowly graded onsets and prolonged durations to be expected of hormonally mediated interactions. 7. Previous studies have indicated that in intact animals the bag cell burst discharge initates a stereotyped egg-laying behavioral pattern that persists for several hours (3, 27). The present data support the hypothesis that certain elements of egg-laying behavior and homeostasis are regulated by a direct action of the bag cells on the central nervous system.

Identification of histaminergic neurons in Aplysia

1990 ◽  
Vol 64 (3) ◽  
pp. 736-744 ◽  
Author(s):  
A. Elste ◽  
J. Koester ◽  
E. Shapiro ◽  
P. Panula ◽  
J. H. Schwartz
Keyword(s):  
Presynaptic Inhibition ◽  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Cerebral Ganglion ◽  
Abdominal Ganglion ◽  
Serotonergic Neuron ◽  
Histaminergic Neurons ◽  
The Central Nervous System ◽  
Bag Cells ◽  
The Right

1. We have identified putative histaminergic neurons in the central nervous system of Aplysia californica by light-microscopic autoradiography after uptake of [3H]histamine and by immunohistochemistry with the use of an antibody specific for histamine. 2. In the cerebral ganglion cells previously shown to contain histamine (C2 and 2 large neighboring cells in the E cluster and a group of smaller cells in the L cluster) were identified both by uptake of [3H]histamine and by histamine immunoreactivity. The identification of C2 was confirmed by experiments in which individual C2s were characterized electrophysiologically and injected with Lucifer yellow before processing for immunohistochemistry. The giant serotonergic neuron did not take up [3H]histamine and was not immunoreactive. 3. In the abdominal ganglion two clusters of cells--one in the left hemiganglion and the other in the right--took up [3H]histamine and were histamine immunoreactive. These clusters are located in the regions occupied by the 30 identified respiratory interneurons, R25 and L25. Individual cells in the R25 and L25 clusters were identified electrophysiologically, marked by injection of Lucifer yellow, and processed for immunocytochemistry. Eleven of the 30 L25 cells examined (from 7 ganglia) and 2 of the 25 R25 cells (from 6 ganglia) that had been marked with Lucifer yellow were also histamine immunoreactive. 4. Also in the abdominal ganglion, identified cells in the L32 cluster were not histamine immunoreactive and did not take up [3H]histamine. These interneurons, which mediate presynaptic inhibition, had previously been considered histaminergic. Neurons in the ganglion known to use transmitters other than histamine (L10, R2, RB cells, and bag cells) were not histamine immunoreactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroendocrine bag cells of Aplysia are activated by bag cell peptide-containing neurons in the pleural ganglion

1989 ◽  
Vol 61 (6) ◽  
pp. 1142-1152 ◽  
Author(s):  
R. O. Brown ◽  
S. M. Pulst ◽  
E. Mayeri
Keyword(s):  
Lucifer Yellow ◽  
Cell Activity ◽  
Feedback Mechanism ◽  
Egg Laying ◽  
Electrophysiological Properties ◽  
Physiological Properties ◽  
Positive Feedback Mechanism ◽  
Bag Cells ◽  
Small Clusters

1. The generation of egg-laying behavior in the marine mollusk Aplysia involves a prolonged burst discharge in the neuroendocrine bag cells, which secrete neuropeptides derived from the egg-laying hormone/bag cell peptide (ELH/BCP) precursor protein. 2. Besides the bag cells, which are located in the abdominal ganglion, small clusters of neurons in the cerebral and pleural ganglia also express the ELH/BCP neuropeptides. We made intracellular recordings from 32 of these ELH/BCP cells in right pleural ganglia, in 18 preparations, to characterize their physiological properties and their functional relationship to the bag cells. 3. The identification of these ELH/BCP cells was confirmed by pressure injection of Lucifer yellow and subsequent immunocytochemical processing for alpha-BCP immunoreactivity. 4. The basic electrophysiological properties of the pleural ELH/BCP cells were similar to those of the bag cells. These pleural cells were directly demonstrated to be electrically coupled, and direct intracellular stimulation of individual pleural ELH/BCP cells initiated prolonged, synchronous burst discharges in the entire cluster through a positive feedback mechanism. 5. Burst discharges elicited in the pleural ELH/BCP cells consistently initiated burst discharges in the bag cells. Bag cell burst discharges were less effective in initiating burst discharges in the pleural ELH/BCP cells, indicating that there were reciprocal but asymmetrical connections. 6. The results show that the pleural ELH/BCP cells are functionally coupled to the bag cells. They support the hypothesis that the pleural ELH/BCP cells are part of the descending pathway that initiates bag cell activity and egg-laying behavior, in vivo.

scholarly journals The Nutrition of the Central Nervous System in the Cockroach Periplaneta Americana L

1960 ◽  
Vol 37 (3) ◽  
pp. 500-512
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plasma Membrane ◽  
Glial Cell ◽  
Glial Cells ◽  
Periplaneta Americana ◽  
Ganglion Cells ◽  
Cell Layer ◽  
Abdominal Ganglion ◽  
The Central Nervous System

1. The histology of the last abdominal ganglion and the cercal nerves and connectives of the cockroach are briefly described. Attention is called to the large cavities, termed the ‘glial lacunar system’, that are present in the glial cell layer of the ganglion; and to the branching filaments of collagen-like material which are laid down within the glial membranes and trabeculae of the ganglia and nerves. 2. Glycogen is stored in large amounts in the perineurium cells, and in small amounts in the interaxonal glial membranes in the neuropile and nerves. Invaginations of the plasma membrane of the large ganglion cells (the ‘trophospongium’) are apparently concerned in the transfer of glycogen. Invaginations and glycogen deposits increase progressively towards the base of the axon. 3. Very small amounts of triglycerides are stored in the ganglion. There are traces only in the perineurium cells; rather more in the glial cells. The invaginations of the glial cells into the large ganglion cells seem to be concerned also in the transfer of lipids to the neurones.

scholarly journals Rapid multi-directed cholinergic transmission in the central nervous system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Santhosh Sethuramanujam ◽  
Akihiro Matsumoto ◽  
Geoff deRosenroll ◽  
Benjamin Murphy-Baum ◽  
J Michael McIntosh ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ganglion Cells ◽  
Release Site ◽  
Amacrine Cells ◽  
Global Scale ◽  
Cholinergic Transmission ◽  
Data Set ◽  
The Central Nervous System ◽  
Synaptic Mechanisms

AbstractIn many parts of the central nervous system, including the retina, it is unclear whether cholinergic transmission is mediated by rapid, point-to-point synaptic mechanisms, or slower, broad-scale ‘non-synaptic’ mechanisms. Here, we characterized the ultrastructural features of cholinergic connections between direction-selective starburst amacrine cells and downstream ganglion cells in an existing serial electron microscopy data set, as well as their functional properties using electrophysiology and two-photon acetylcholine (ACh) imaging. Correlative results demonstrate that a ‘tripartite’ structure facilitates a ‘multi-directed’ form of transmission, in which ACh released from a single vesicle rapidly (~1 ms) co-activates receptors expressed in multiple neurons located within ~1 µm of the release site. Cholinergic signals are direction-selective at a local, but not global scale, and facilitate the transfer of information from starburst to ganglion cell dendrites. These results suggest a distinct operational framework for cholinergic signaling that bears the hallmarks of synaptic and non-synaptic forms of transmission.

scholarly journals Cytotoxic and anti-excitotoxic effects of selected plant and algal extracts using COMET and cell viability assays

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abeer Aldbass ◽  
Musarat Amina ◽  
Nawal M. Al Musayeib ◽  
Ramesa Shafi Bhat ◽  
Sara Al-Rashed ◽  
...  
Keyword(s):  
Cell Viability ◽  
Plant Extracts ◽  
Ganglion Cells ◽  
Cell Damage ◽  
Primary Cultures ◽  
Glutamate Excitotoxicity ◽  
Retinal Ganglion ◽  
Gradual Loss ◽  
The Central Nervous System ◽  
Mtt Assays

AbstractExcess glutamate in the central nervous system may be a major cause of neurodegenerative diseases with gradual loss and dysfunction of neurons. Primary or secondary metabolites from medicinal plants and algae show potential for treatment of glutamate-induced excitotoxicity. Three plant extracts were evaluated for impact on glutamate excitotoxicity-induced in primary cultures of retinal ganglion cells (RGC). These cells were treated separately in seven groups: control; Plicosepalus. curviflorus treated; Saussurea lappa treated; Cladophora glomerate treated. Cells were treated independently with 5, 10, 50, or 100 µg/ml of extracts of plant or alga material, respectively, for 2 h. Glutamate-treated cells (48 h with 5, 10, 50, or 100 µM glutamate); and P. curviflorus/glutamate; S. lappa/glutamate; C. glomerata/glutamate [pretreatment with extract for 2 h (50 and 100 µg/ml) before glutamate treatment with 100 µM for 48 h]. Comet and MTT assays were used to assess cell damage and cell viability. The number of viable cells fell significantly after glutamate exposure. Exposure to plant extracts caused no notable effect of viability. All tested plants extracts showed a protective effect against glutamate excitotoxicity-induced RGC death. Use of these extracts for neurological conditions related to excitotoxicity and oxidative stress might prove beneficial.

The development of central nervous system control of the gill withdrawal reflex evoked by siphon stimulation in Aplysia

1979 ◽  
Vol 57 (9) ◽  
pp. 987-997 ◽  
Author(s):  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Abdominal Ganglion ◽  
System Control ◽  
Reflex Amplitude ◽  
Withdrawal Reflex ◽  
Reflex Latency ◽  
Neural Processes ◽  
The Central Nervous System ◽  
Cns Control

In older Aplysia, the central nervous system (CNS) (abdominal ganglion) exerts suppressive and facilitatory control over the peripheral nervous system (PNS) which initially mediates the gill withdrawal reflex and its subsequent habituation evoked by tactile stimulation of the siphon. In young animals, both the suppressive and facilitatory CNS control were found to be absent. In older animals, removal of branchial nerve (Br) input to the gill resulted in a significantly reduced reflex latency and, with ctenidial (Ct) and siphon (Sn) nerves intact, a significantly increased reflex amplitude and an inability of the reflex to habituate with repeated siphon stimulation. In young animals, removal of Br had no effect on reflex latency and with Ct and Sn intact, the reflex amplitude latency was not increased and the reflex habituated. Older animals can easily discriminate between different intensity stimuli applied to the siphon as evidenced by differences in reflex amplitude, rates of habituation, and evoked neural activity. On the other hand, young animals cannot discriminate well between different stimulus intensities. The lack of CNS control in young animals was found to be due to incompletely developed neural processes within the abdominal ganglion and not the PNS. The lack of CNS control in young Aplysia results in gill reflex behaviours being less adaptive in light of changing stimulus conditions, but may be of positive survival value in that the young will not habituate as easily. The fact that CNS control is present in older animals strengthens the idea that in any analysis of the underlying neural mechanisms of habituation the entire integrated CNS–PNS must be taken into account.

scholarly journals Components of a Response Programme Involving Inhibitory and Excitatory Reflexes in the Surf Clam

1970 ◽  
Vol 53 (3) ◽  
pp. 711-725
Author(s):  
DEFOREST MELLON ◽  
DAVID J. PRIOR
Keyword(s):  
Ganglion Cells ◽  
Adductor Muscle ◽  
Type I ◽  
Surf Clam ◽  
Response Characteristics ◽  
Sensory Pathways ◽  
Intact Muscle ◽  
Input Organization ◽  
The Central Nervous System ◽  
Muscle Groups

1. Electrical records from ganglion cells in the central nervous system and from intact muscle groups controlling siphon retraction and shell-valve adduction have revealed qualitative similarities in the response characteristics of two neurone-effector systems following stimulation of tactile afferents. 2. Simultaneous electrical records from neurones and muscle indicate that Type I ganglion cells are motoneurones to the fast portion of the posterior adductor muscle. 3. The waveform and polarity of the post-synaptic responses of Type 1 cells depend critically upon the intensity of stimulation over intact sensory pathways. High-intensity input transiently excites the fast portion of the adductor; low-intensity input inhibits the adductor motoneurones. The input organization of Type I neurones therefore permits discrimination of stimulus magnitude and thus controls the characteristics of the response programme.

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