Journal article
Role of cAMP Cascade in Synaptic Stability and Plasticity: Ultrastructural and Physiological Analyses of Individual Synaptic Boutons in Drosophila Memory Mutants
The Journal of neuroscience, Vol.20(11), pp.3980-3992
06/01/2000
DOI: 10.1523/JNEUROSCI.20-11-03980.2000
PMCID: PMC6772635
PMID: 10818133
Abstract
Mutations of the genes
rutabaga
(
rut
) and
dunce
(
dnc
) affect the synthesis and degradation of cAMP, respectively, and disrupt learning in
Drosophila
. Combined ultrastructural analysis and focal electrophysiological recording in the larval neuromuscular junction revealed a loss of stability and fine tuning of synaptic structure and function in both mutants. Increased ratios of docked/undocked vesicles and poorly defined synaptic specializations characterized
dnc
synapses. In contrast,
rut
boutons possessed fewer, although larger, synapses with lower proportions of docked vesicles. At reduced Ca
2+
levels, decreased quantal content coupled with an increase in failure rate was seen in
rut
boutons and reduced pair-pulse facilitation were found in both
rut
and
dnc
mutants. At physiological Ca
2+
levels, strong enhancement, instead of depression, in evoked release was observed in some
dnc
and
rut
boutons during 10 Hz tetanus. Furthermore, increased variability of synaptic transmission, including fluctuation and asynchronicity of evoked release, paralleled an increase in synapse size variation in both
dnc
and
rut
boutons, which might impose problems for effective signal processing in the nervous system. Pharmacological and genetic studies indicated broader ranges of physiological alteration by
dnc
and
rut
mutations than either the acute effects of cAMP analogs or the available mutations that affect cAMP-dependent protein kinase (PKA) activity. This is consistent with previous reports of more severe learning defects in
dnc
and
rut
mutations than these PKA mutants and allows identification of the phenotypes involving long-term developmental regulation and those conferred by PKA.
Details
- Title: Subtitle
- Role of cAMP Cascade in Synaptic Stability and Plasticity: Ultrastructural and Physiological Analyses of Individual Synaptic Boutons in Drosophila Memory Mutants
- Creators
- John J RengerAtsushi UedaHarold L AtwoodC. K GovindChun-Fang Wu
- Resource Type
- Journal article
- Publication Details
- The Journal of neuroscience, Vol.20(11), pp.3980-3992
- Publisher
- Society for Neuroscience
- DOI
- 10.1523/JNEUROSCI.20-11-03980.2000
- PMID
- 10818133
- PMCID
- PMC6772635
- ISSN
- 0270-6474
- eISSN
- 1529-2401
- Language
- English
- Date published
- 06/01/2000
- Academic Unit
- Iowa Neuroscience Institute; Biology
- Record Identifier
- 9984070780502771
Metrics
8 Record Views