New Tomographic Insight on Linkage Between Receptor-Like Intracellular Structures Across the Synaptic Cleft
Andy A. Cole and Thomas S. Reese
(see pages 5883–5892)
Excitatory and inhibitory synapses between neurons are critical for neuron communication and circuit functionality, which underlie all forms of cognition and behavior. The synapse is composed of presynaptic neuron axons, postsynaptic dendrites of neurons, and the clefts in between. Microscopic imaging techniques have revealed much about synapse structure and the molecular machinery required for its functioning. Separate filament types enable the clustering of vesicles and vesicle fusion to synaptic membranes for release of neurotransmitters into the cleft and onto their respective receptors. But the coordinated organization of molecules and filaments on and between synaptic membranes, which enables these components to influence each other, is not well understood. Recent tomographic evidence suggests that this coordinated organization may be regulated by “transsynaptic assemblies,” or receptor-like structures that align across the synapse. A study in this issue provides more tomographic detail about these structures; investigators analyzed the distribution and connectivity of structures in the synaptic clefts of excitatory and inhibitory synapses in rat hippocampal neuron cultures and determined that many transsynaptic assemblies connect to both vesicles and postsynaptic scaffolding. Additionally, intracellular components are often shared between assemblies to form larger “association domains” in areas where vesicles are clustered. Thus, transsynaptic assemblies seem to be pivotal for the structural integrity of the synapse, aligning presynaptic and postsynaptic elements across the synaptic cleft. These findings advance our understanding of synapse structure and functioning. Moreover, they may point to novel mechanisms underlying diseases in which neuron communication is hindered.
A transsynaptic assembly with no intracellular structure is considered transcleft only (pink); an assembly that contains a transcleft structure connected to an intracellular structure on one side of the synapse is classified as a partial assembly (yellow); and an assembly with a transcleft structure connected to intracellular structures on both sides is classified as a full transsynaptic assembly (blue). Scale bars, 40 nm.
Parent–Child Neural Similarities Contribute to Child Emotional Development in a Context-Dependent Manner
Zexi Zhou, Ya-Yun Chen, Beiming Yang, Yang Qu, and Tae-Ho Lee
(see pages 5936–5943)
How much influence do parents have on the emotional development of their children? This is a question that receives much debate, and neuroscientists have begun to weigh in. Recent fMRI evidence suggests that neural similarities in the way parents and their children process emotions could potentially impact the emotional development of children, although this has not been firmly established. Moreover, whether the influence of parent–child neural similarity on emotional adjustment is context-dependent remains to be seen. Researchers in this issue explored these unknowns. They first investigated whether parent–child neural similarity impacts information processing while watching emotional movies, predicting that greater similarity in neural networks between parents and their children during movie viewing would be associated with reduced depressive symptoms, less anxiety, and elevated ego resilience in youth. They also examined whether family cohesion, or the context of how closely bonded children and their parents are, plays a role in moderating this relationship. They found that higher parent–child similarity in the functional connectivity of emotional processing regions was associated with better emotional adjustment in children. Notably, this association was significant only in families with high cohesion. These findings provide the first evidence that children can benefit from attuned neural processes with their parents. Moreover, they demonstrate that family cohesion is a critical variable to consider when evaluating whether these neural similarities impact development and could inform treatment strategies for impaired emotional development in children.
Footnotes
This Week in The Journal was written by Paige McKeon
