The activity-dependent plasticity of synapses is believed to be the cellular basis of learning. These synaptic changes are mediated through the coordination of local biochemical reactions in synapses and changes in gene transcription in the nucleus to modulate neuronal circuits and behavior. The protein kinase C (PKC) family of isozymes has long been established as critical for synaptic plasticity. However, because of a lack of suitable isozyme-specific tools, the role of the novel subfamily of PKC isozymes is largely unknown. Here, through the development of fluorescence lifetime imaging-fluorescence resonance energy transfer activity sensors, we investigate novel PKC isozymes in synaptic plasticity in CA1 pyramidal neurons of mice of either sex. We find that PKC is activated downstream of TrkB and DAG production, and that the spatiotemporal nature of its activation depends on the plasticity stimulation. In response to single-spine plasticity, PKC is activated primarily in the stimulated spine and is required for local expression of plasticity. However, in response to multispine stimulation, a long-lasting and spreading activation of PKC scales with the number of spines stimulated and, by regulating cAMP response-element binding protein activity, couples spine plasticity to transcription in the nucleus. Thus, PKC plays a dual functional role in facilitating synaptic plasticity.
SIGNIFICANCE STATEMENT Synaptic plasticity, or the ability to change the strength of the connections between neurons, underlies learning and memory and is critical for brain health. The protein kinase C (PKC) family is central to this process. However, understanding how these kinases work to mediate plasticity has been limited by a lack of tools to visualize and perturb their activity. Here, we introduce and use new tools to reveal a dual role for PKC in facilitating local synaptic plasticity and stabilizing this plasticity through spine-to-nucleus signaling to regulate transcription. This work provides new tools to overcome limitations in studying isozyme-specific PKC function and provides insight into molecular mechanisms of synaptic plasticity.
If you do not see content above, kindly GO TO SOURCE.
Not all publishers encode content in a way that enables republishing at Neuro.vip.
This post is Copyright: Colgan, L. A., Parra-Bueno, P., Holman, H. L., Tu, X., Jain, A., Calubag, M. F., Misler, J. A., Gary, C., Oz, G., Suponitsky-Kroyter, I., Okaz, E., Yasuda, R. | July 27, 2023
Journal of Neuroscience current issue