Research summary
Synapsin I (protein I), a neuron-specific phosphoprotein and substrate for cAMP-dependent and Ca2+/calmodulin-dependent kinases, was shown by light- and electron-microscope immunocytochemistry to be associated with the majority of nerve terminals, where it localises primarily to synaptic vesicles. A highly purified rat-brain synaptic-vesicle preparation confirmed the association biochemically, supporting the model that synapsin I controls the releasable fraction of vesicles via its phosphorylation state [3]. A subsequent review summarised how phosphorylation of synapsin I and other vesicle-associated phosphoproteins regulates synaptic transmission and, by extension, learning and memory [1]. A dopamine-sensitive adenylate cyclase was demonstrated in homogenates of rat caudate-nucleus brain tissue. The enzyme was half-maximally activated at 4 microM dopamine and stimulated by concentrations as low as 0.3 microM; apomorphine mimicked the activation while haloperidol and chlorpromazine blocked it, consistent with the pharmacological signature of a dopamine receptor, making this enzyme an early candidate for the postsynaptic dopamine-receptor effector [4]. A broader review identified phosphorylated proteins as physiological effectors of regulatory substances (neurotransmitters, hormones), including those that act independently of cyclic AMP, arguing that protein phosphorylation is a unifying transduction mechanism for many regulatory pathways [5]. Dopaminergic control of striatal synaptic plasticity at corticostriatal medium-spiny-neuron synapses was tested using DA-receptor transgenic mice. The prevailing model assigns LTP induction to D1 receptors and LTD induction to D2 receptors and demands unidirectional plasticity in each MSN population. Slice recordings showed that dopamine acts complementarily in D1- and D2-type MSNs so that synaptic plasticity is bidirectional and Hebbian in both populations, with implications for striatal models of Parkinson's disease [2].
Recent publications
- Maintenance of pluripotency in human and mouse embryonic stem cells through activation of Wnt signaling by a pharmacological GSK-3-specific inhibitorDOI
- Regulation of NMDA receptor trafficking by amyloid-βDOI
- Synaptic Vesicle Phosphoproteins and Regulation of Synaptic FunctionDOI
- Dichotomous Dopaminergic Control of Striatal Synaptic PlasticityDOI
- A Translational Profiling Approach for the Molecular Characterization of CNS Cell TypesDOI
- Synapsin I (protein I), a nerve terminal-specific phosphoprotein. III. Its association with synaptic vesicles studied in a highly purified synaptic vesicle preparation.DOI
- Dopamine-sensitive adenylate cyclase in caudate nucleus of rat brain, and its similarity to the “dopamine receptor”DOI
- Intraneuronal Aβ42 Accumulation in Human BrainDOI
- Phosphorylated Proteins as Physiological EffectorsDOI
- Application of a Translational Profiling Approach for the Comparative Analysis of CNS Cell TypesDOI
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Email Paul Greengard 6-12 months before your application deadline. Read several recent papers and reference specific work in your message. Use our how to email a Japanese professor guide for the proven email structure.
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External profiles
- ORCID: https://orcid.org/0000-0002-4437-0893
- OpenAlex: openalex.org
Profile compiled from public sources (Researchmap, OpenAlex, Osaka University faculty directory). Last refreshed 2026-05. Report incorrect information.