The effect of ions and second messengers on long‐term potentiation of chemical transmission in avian ciliary ganglia

Scott, T; Bennett, Max R.

doi:10.1111/j.1476-5381.1993.tb13833.x

Cited by 40 publications

(36 citation statements)

References 34 publications

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“…If calcium levels in the nerve terminals are determined directly using calcium imaging techniques, then these seem to be elevated for at least 15 min into the LTP period (Larkum, Warren & Bennett, 1993). The use of short-term facilitation to measure calcium levels in the terminal indicates that this ion is elevated during at least the first 15 min after a tetanus (Scott & Bennett, 1993a). The increase in quantal content of the EPSP observed during LTP in the present work may therefore be due to an increase in the basal level of calcium in the terminal.…”

Section: Discussionmentioning

confidence: 54%

“…The only one of these processes that has been shown to be implicated in at least the induction phase of LTP in autonomic ganglia is calmodulin. LTP fails to appear after a tetanus if calmodulin is inhibited in either frog sympathetic ganglia (Minota et al 1991) or chick ciliary ganglia (Scott & Bennett, 1993a). Given the dependence of LTP induction and maintenance on a raised calcium level, it is likely that calcium-calmodulin is important in the induction and maintenance of LTP.…”

Section: Discussionmentioning

confidence: 99%

“…Blocking either calmodulin or the rise in calcium in the nerve terminal that accompanies a tetanus blocks the induction of LTP in ciliary ganglia (Scott & Bennett, 1993a). As these conditions would also be expected to block the production of NO, it is possible that the induction of LTP is dependent on NO.…”

mentioning

confidence: 99%

“…In bullfrog sympathetic ganglia, LTP is mainly due to an increase in the number of quanta secreted, although in some neurones it involves an increase in postsynaptic sensitivity to acetylcholine (Koyano, Kuba & Minota, 1985). Recently, LTP has been described in the parasympathetic ciliary ganglia of the chick following a tetanus (Scott & Bennett, 1993a) and after post-tetanic potentiation has declined (Poage & Zengel, 1993). It has not been established if this LTPis due to an increase in quantal secretion, an increase in postsynaptic sensitivity to acetylcholine, or both.…”

mentioning

confidence: 99%

“…Long-term potentiation (LTP) of synaptic transmission, in w7hich the efficacy of transmission is elevated for more than 30 min, occurs in autonomic ganglia (Dunant & Dolivo, 1968;Scott & Bennett, 1993a; for a review, see Kuba & Kumamoto, 1990). In rat sympathetic ganglia a tetanus (5-20 Hz for 5-20 s) is followed by a several hundred percent increase in synaptic efficacy which declines rapidly at first with a time constant of 2-3 min and then more slowly over an hour or so.…”

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confidence: 99%

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Nitric oxide modulation of quantal secretion in chick ciliary ganglia.

Lin

Bennett

1994

The Journal of Physiology

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1. Long-term potentiation of quantal secretion was studied at ciliary ganglion synapses of post-hatched birds following tetanic stimulation of the oculomotor nerve and the effects of nitric oxide (NO) on quantal secretion were determined. 2. Tetanic stimulation of the oculomotor nerve at 30 Hz for 20 s at room temperature increased the amplitude of the excitatory postsynaptic potential (EPSP) by about 100 %; 1-2 min after the tetanus the EPSP declined exponentially with a time constant of about 10 min (long-term potentiation; LTP). LTP was due to an increase in the quantal content of the EPSP not to a change in quantal size. 3. A component of LTP was shown to be due to the release of NO in the ganglion, as blocking the synthesis of NO with L-arginine methyl ester decreased the potentiation by 70%. 4. Exogenous application of NO using sodium nitroprusside increased the amplitude of the EPSP by more than 30 % due to an increase in the quantal content of the EPSP. 5. Both 8-bromo-cGMP and 8-bromo-cAMP increased the quantal content of the EPSP by more than 44 % without changing the quantal size. 6. The results suggest that endogenous NO is involved in either the initiation or maintenance phase of LTP. This may occur through an increase in quantal secretion consequent on the action of an elevated cGMP increasing cAMP.

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Section: Discussionmentioning

confidence: 54%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Nitric oxide modulation of quantal secretion in chick ciliary ganglia.

Lin

Bennett

1994

The Journal of Physiology

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Hypothyroidism impairs long‐term potentiation in sympathetic ganglia: Electrophysiologic and molecular studies

Alzoubi

Bedawi

Aleisa

et al. 2004

J of Neuroscience Research

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Electrophysiologic and molecular techniques were used to study the effect of adult-onset hypothyroidism on synaptic plasticity in the superior cervical sympathetic ganglion. Ganglia excised from adult thyroidectomized and sham-operated rats were subjected to a brief high-frequency stimulation of the preganglionic nerve to express long-term potentiation (gLTP). Western blotting was carried out to determine the protein levels of key signaling molecules that may be involved in the expression of gLTP. Input/output relationship in ganglia from hypothyroid rats indicated a normal basal synaptic transmission, whereas activity-dependent types of synaptic plasticity, posttetanic potentiation (PTP) and gLTP, were impaired. Immunoblot analysis showed that both calcium/calmodulin kinase II (CaMKII) and phosphorylated CaMKII (P-CaMKII) levels were reduced markedly in hypothyroid rat ganglia compared to those from euthyroid controls. Additionally, protein levels of nitric oxide synthase-1, heme oxygenase-2, calmodulin, protein kinase C (PKC), and calcineurin were also reduced in hypothyroid rat ganglia. The results indicate that abnormally low basal levels of signaling molecules may be responsible for hypothyroidism-induced impairment of gLTP in superior cervical ganglia. In addition, the results indicate that synaptic plasticity in sympathetic ganglia may involve a molecular sequence of events similar to that proposed for LTP in the hippocampus.

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Immediate early gene expression related to learning and retention of a visual discrimination task in bamboo sharks (Chiloscyllium griseum)

Fuss

Schluessel

2018

Brain Struct Funct

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Using the expression of the immediate early gene (IEG) egr-1 as a neuronal activity marker, brain regions potentially involved in learning and long-term memory functions in the grey bamboo shark were assessed with respect to selected visual discrimination abilities. Immunocytochemistry revealed a significant up-regulation of egr-1 expression levels in a small region of the telencephalon of all trained sharks (i.e., 'early' and 'late learners', 'recallers') when compared to three control groups (i.e., 'controls', 'undisturbed swimmers', 'constant movers'). There was also a well-defined difference in egr-1 expression patterns between the three control groups. Additionally, some staining was observed in diencephalic and mesencephalic sections; however, staining here was weak and occurred only irregularly within and between groups. Therefore, it could have either resulted from unintentional cognitive or non-cognitive inducements (i.e., relating to the mental processes of perception, learning, memory, and judgment, as contrasted with emotional and volitional processes) rather than being a training effect. Present findings emphasize a relationship between the training conditions and the corresponding egr-1 expression levels found in the telencephalon of Chiloscyllium griseum. Results suggest important similarities in the neuronal plasticity and activity-dependent IEG expression of the elasmobranch brain with other vertebrate groups. The presence of the egr-1 gene seems to be evolutionarily conserved and may therefore be particularly useful for identifying functional neural responses within this group.

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The effect of ions and second messengers on long‐term potentiation of chemical transmission in avian ciliary ganglia

Cited by 40 publications

References 34 publications

Nitric oxide modulation of quantal secretion in chick ciliary ganglia.

Nitric oxide modulation of quantal secretion in chick ciliary ganglia.

Hypothyroidism impairs long‐term potentiation in sympathetic ganglia: Electrophysiologic and molecular studies

Immediate early gene expression related to learning and retention of a visual discrimination task in bamboo sharks (Chiloscyllium griseum)

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