Findings weaken notion that size equals strength for neural connections
Learning, memory, and behavioral disorders can arise when the connections between neurons, called synapses, do not change properly in response to experience. Scientists have studied this “synaptic plasticity” for decades, but a new study by researchers at MIT’s Picower Institute for Learning and Memory highlights several surprises about some of the basic mechanisms by which it happens. Getting to the bottom of what underlies some of those surprises, the research further suggests, could yield new treatments for a disorder called Fragile X that causes autism. Two classic forms of synaptic plasticity are that synapses either get stronger or weaker and that the tiny spine structures that support them get bigger or smaller. For a long time, the field’s working assumption has been that these functional and structural changes were closely associated: Strengthening went along with an increase in spine size and weakening preceded spine shrinkage. But the study published in Molecular...