Impulse Identification and Axon Mapping of the Nine Neurons in the Cardiac Ganglion of the Lobster Homarus Americanus

1967 ◽  
Vol 47 (2) ◽  
pp. 327-341
Author(s):  
DANIEL K. HARTLINE

1. Simultaneous recording from several pairs of electrodes placed along the ganglion and certain efferent nerves, during stimulation of other efferents, allows the course of antidromic impulses in each stimulated axon to be mapped. 2. These impulses disappear as they approach their somata, being incapable of invading them, a fact which permits identification of a particular efferent axon with a particular soma. 3. By these means the courses of all such efferent axons, and their corresponding somata, have been determined. These all belong to the five large cells. 4. The impulses from each such axon occurring during the spontaneous burst can be identified, as can impulses from each small cell. 5. Each large-cell axon appears to be inexcitable until it is a few mm from the soma. 6. If the axon branches within this inexcitable region, the branches tend to fire impulses independently. 7. The technique of cell identification opens the way to a more complete analysis of the ganglion's activity and the synaptic interactions which produce it.

1973 ◽  
Vol 62 (4) ◽  
pp. 448-472 ◽  
Author(s):  
Earl Mayeri

External recording and stimulation, techniques were used to determine which neurons and interactions are essential for production of the periodic burst discharge in the lobster cardiac ganglion. Burst activity can be modulated by brief single shocks applied to the four small cells, but not by similar stimulation of the five large cells, suggesting that normally one or more small cells primarily determine burst rate and duration. Repetitive electrical stimulation of large cells initiates spike activity in small cells, probably via excitatory synaptic and/or electrotonic connections which may normally act to prolong bursts and decrease burst rate. Transection of the ganglion can result in burst activity in small cells in the partial or complete absence of large cell spike activity, but large cells isolated from small cell excitatory synaptic input by transection or by application of dinitrophenol do not burst. Generally, transections which decrease excitatory feedback to small cells are accompanied by an increase in burst rate, but mean spike frequency over an entire burst cycle stabilizes at the original level within 10–30 min for various groups of cells whose spike-initiating sites are still intact. These and previous results suggest that the system is two layered: one or more small cells generate the burst pattern and impose it on the large cells which are the system's motorneurons.


1975 ◽  
Vol 63 (1) ◽  
pp. 33-52
Author(s):  
I. M. Cooke ◽  
D. K. Hartline

The spontaneous burst discharges of isolated lobster (Homarus americanus) cardiac ganglia were recorded with a spaced array of electrodes. Small regions (less than 1 mm) of the ganglion were exposed to the cardioexcitor neurohormone in extracts of pericardial organs (XPO) or to 10(−5) M 5-hydroxytryptamine (5HT). All axons were excited (increased mean firing frequency, f) by both substances, but only by applications in the region between the soma (but excluding it) and proximal site of impulse initiation. Units not so exposed changed their f relatively little despite f increases of as much as threefold in exposed units and changes in burst rate and overall length. Regularity and grouping of all impulse activity into bursts was never disturbed. 5HT increases burst rate at any point of application. The increases are larger if small cells are affected than if only large cells are exposed. Burst length decreases except when the pacemaker is affected. In contrast, XPO affects neither burst rate or length unless small cells are affected. Length is increased if non-pacemaker small cells are affected; both rate and length increase if the pacemaker is affected. The pacemaker usually exhibits an f of intermediate value. Rate changes are not simply related to its f. A small cell can “burst” in the absence of impulses from any other cells. XPO may enhance endogenous “driver potentials,” while 5HT may excite by depolarizing at limited sites.


1979 ◽  
Vol 42 (4) ◽  
pp. 975-999 ◽  
Author(s):  
K. Tazaki ◽  
I. M. Cooke

1. Semi-isolated preparations of the nine-celled cardiac ganglion of the crab, Portunus sanguinolentus, were studied electrophysiologically, using simultaneous recording from extracellular and two or three intracellular electrodes. Nine penetrations of small cells were achieved. 2. Three large (80 x 120 micron) cells lie near the anterior end of the 5-mm main trunk; two large and four small (less than 50 micron) cells at the posterior end. Large-cell axons pass along the main trunk and then exit to innervate cardiac muscle; small-cell axons do not leave the ganglion. 3. The semi-isolated ganglion produces spontaneous electrical activity organized into regularly patterned, rhythmic bursts of large- and small-cell impulses recurring at rates of 0.3-0.6/s and lasting 500-800 ms. Small impulse activity commences and ends each burst. Small cells fire trains during the burst, but impulses are not synchronized among them. Large-cell trains are synchronous, are at about one-half the frequency, and have fewer impulses than small-cell trains. 4. Intracellular recordings from small cells show a slow, pacemaker depolarization from a maximum membrane potential of -54 mV leading with only a slight inflection at ca. -50 mV to a depolarized plateau at ca. -40 mV; nonovershooting impulses are superimposed on this but cease before it repolarizes. Impulses, therefore, arise at a site distant from the soma and do not invade it. Deflections suggesting synaptic potentials are not seen. 5. Intracellular recordings from large cells show complex depolarizations corresponding to extracellularly recorded bursts. These represent excitatory postsynaptic potentials (EPSPs) corresponding with individual small-cell impulses, attenuated, non-overshooting spikes, and an underlying slow depolarization; usually no pacemaker depolarization is apparent between bursts. Chemically mediated transmission is probable for the EPSPs because they show delay, increase in amplitude with hyperpolarization, sometimes show facilitation, and are reduced in saline having one-third Ca, 3 x Mg. 6. EPSPs, impulses, and the slow depolarization occur synchronously among the large cells. Potentials recorded from posterior cells are attenuated and slower than those of the anterior cells. This is interpreted to reflect sites of occurrence more distant from the soma in the posterior than in the anterior cells. Impulses do not invade the somata. 7. Intracellular recordings from large-cell axons 4 mm from the soma show overshooting action potentials arising sharply from a base line. EPSPs are absent or highly attenuated and there is little underlying depolarization (less than 2 mV). 8. Current passing with electrodes intracellular to two cells has established directly that all large cells are electrotonically coupled and that an anterior cell and a small cell are coupled. Changes of burst rate during current passing into any large cell indicate that all large cells and small cells are electrotonically coupled. 9...


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A54-A54
Author(s):  
Mahsa Khanlari ◽  
Shaoying Li ◽  
Roberto N Miranda ◽  
Swaminathan Iyer ◽  
Cameron Yin ◽  
...  

BackgroundSeveral morphologic patterns of ALK+ anaplastic large cell lymphoma (ALCL) are recognized: common, small cell, lymphohistiocytic, Hodgkin-like, and composite patterns.1 Small cell (SC) and lymphohistiocytic (LH) patterns are thought to be closely associated with poorer outcome in children with ALK+ ALCL.2 However, the clinicopathologic and prognostic features of SC/LH patterns of ALK+ ALCL are not yet reported in adults. Recently, we found PD-L1 expression in a large subset of ALK+ ALCL cases, however, PD-L1 expression in SC/LH versus non-SC/LH ALCL has not been reported.MethodsAmong 102 adult patients with ALK+ ALCL seen at our institution from January 1, 2007 through August 30, 2018, 18 (18%) cases had a SC and/or LH pattern. The clinical, pathologic, and outcome data were compared between SC/LH and non-SC/LH ALK+ ALCL cases using Fisher’s exact test. Overall survival (OS) was analyzed using the Kaplan-Meier method and compared using the log-rank test.ResultsThere were no significant differences in clinical features including age, gender, nodal versus extranodal involvement, B symptoms, stage, leukocytosis/lymphocytosis, and serum LDH levels between patients with SC/LH versus non-SC/LH ALK+ ALCL. Compared to non-SC/LH cases, SC/LH ALCL was more often positive for CD2 (92% vs. 36%, p = 0.0007), CD3 (81% vs. 15%, p = 0.0001), CD7 (80% vs. 37%, p = 0.03), and CD8 (54% vs. 7%, p = 0.0006). SC/LH ALCL showed a trend of decreased PD-L1 expression than non-SC/LH cases (24% vs. 46%, p = 0.11). There were no significant differences in the expression of CD4, CD5, CD25, CD43, CD45, CD56, TCR A/B, TCR G/D, cytotoxic markers, EMA, Ki-67 proliferation index. The induction chemotherapy and response rate in patients with SC/LH ALK+ ALCL were similar to patients with non-SC/LH ALK+ ALCL. After a median follow-up of 30.5 months (range, 0.3–224 months), there was no significant difference in OS between patients with SC/LH versus non-SC/LH ALK+ ALCL (p = 0.88).ConclusionsIn adults with ALK+ALCL, the SC/LH morphologic pattern is associated with a CD8+ T cell immunophenotype and retention of expression of T cell markers (CD2, CD3, and CD7). The trend of decreased PD-L1 expression in SC/LH ALCL suggests that these patients may not be ideal candidates for PD-L1 immunotherapy. The SC/LH patterns of ALK+ ALCL have no impact on the prognosis of adult patients which is in contrast to the reported association of the SC/LH patterns with poorer outcome in children with ALK+ ALCL.Ethics ApprovalThe study was approved by the Institutional Review Board at MD Anderson Cancer Center, Approval number: PA16-0897ReferencesSwerdlow SH, Campo E, The 2016 revision of the World Health Organization classification of lymphoid neoplasms. Blood 2016;127:2375–2390.Brugières L, Deley MC, CD30 (+) anaplastic large-cell lymphoma in children: Analysis of 82 patients enrolled in two consecutive studies of the French Society of Pediatric Oncology. Blood 1998;92:3591–3598.


2000 ◽  
Vol 264 (3) ◽  
pp. 157-158 ◽  
Author(s):  
G. Di Vagno ◽  
G. A. Melilli ◽  
G. Cormio ◽  
D. Piscitelli ◽  
A. Ciampolillo ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document