Researchers Define Function of an Enigmatic Synaptic Protein
Source: Institute of Science and Technology Austria
Summary: In a new study researchers have resolved the role of an enigmatic synaptic protein during signal transmission at an inhibitory synapse.
The neurons in the brain communicate with each other by sending chemical or electronic signals across the synapse. To send a signal the molecular machinery requires not only the neurotransmitter signal itself but also a wide variety of proteins which act as sensors, effectors, modulators and scaffolds. Other family of proteins synaptotagmins are also part of this complex machinery. Humans have 17 different varieties of synaptotagmins proteins, yet the function of most of these proteins are not well understood. Researchers from the Institute of Science and Technology Austria in a new study have resolved the role of synaptotagmin 7 in signal transmission at an inhibitory synapse. The findings were published in the journal Cell Reports.
In the Previous study, Jonas and Chen found that synaptotagmin 2 is the calcium sensor that makes certain GABA synapses fast. But in the current study, they found that synaptotagmin 7 ensures the efficiency at the high-frequency inhibitory synaptic transmission (GABAergic synapse between the basket cells (BCs) and Purkinje cells (PCs) in the cerebellum). When looked at the level of neural networks they found that the activity of a Purkinje cell is controlled by single basket cells which is mediated by synaptotagmin 7. It also appears to function as calcium sensor and is responsible for a phenomenon called asynchronous transmitter release.
Lead author, Peter Jonas said, “The role of synaptotagmin 7 has been controversial. For the first time, we defined its functional contribution at an inhibitory GABAergic synapse” and further added, “We have identified a critical role for synaptotagmin 7 in maintaining the efficacy of transmission at GABAergic synapses in the cerebellum and hippocampus.”
More Information: Chong Chen et al, “Triple Function of Synaptotagmin 7 Ensures Efficiency of High-Frequency Transmission at Central GABAergic Synapses”, Cell Reports (2017). DOI: http://dx.doi.org/10.1016/j.celrep.2017.10.122