By GREGORY ZELLER //
Unt now, ve vill brainvash zese lab rats to hate zeir favorite foods! Hahahaha!
What sounds like an iffy plot from a B-grade ’50s sci-fi flick is actually the core of a new Stony Brook University study. And it’s fairly cutting-edge stuff, according to the university, with the “taste aversion” research unlocking secrets about the complex relationship between brain activity and behavior – and dispelling popular beliefs about the formation of memories.
Credited to four researchers from SBU’s Department of Neurobiology and Behavior and published in the peer-reviewed, open-access biomedical and life sciences journal eLife, the new study – “LTD at Amygdalocortical Synapses as a Novel Mechanism for Hedonic Learning” – shows how different areas of the brain work together to alter behavior, based on good and bad experiences.
In the study, scientists conditioned laboratory rats to dislike sugar water – something they’d normally like – by “creating a mild digestive malaise after consumption.”
Powerful memories are formed when a pleasant taste is associated with gastrointestinal pain, such as an aversion to a particular food after a case of food poisoning. Science has long known this – but how the brain actually forms that long-lasting memory has been a matter of debate, with conventional wisdom crediting memory formation to the activation of certain neurons.
Enter the SBU study, which discovered that “conditioned taste-aversion learning” decreases the strength of certain synaptic connections, leading to “an overall decreased activation of neurons in the gustatory cortex” – thick lab talk that suggests, simply, that memories might not form the way science thought.
Memory formation via neuron activation might not be the only way we remember what we remember, according to Melissa Haley, a postdoctoral fellow in the Maffei Lab, operating under the auspices of Arianna Maffei, a professor in SBU’s Department of Neurobiology and its Renaissance School of Medicine.
“Our experiments provide the first direct evidence that learning to avoid certain tastes depends on the long-term reduction in the activity in connections between taste and threat sensors in the brain,” Haley said. “The findings also suggest reducing the activity between two brain centers can be an important way in which animals learn other behaviors.”
All of which “adds to our understanding of the processes that enable the formation of memories and lead to changes in behavior,” added the postdoc, who earned a PhD in neurobiology and behavior from SBU in 2017.
The research – which also involved contributions from Alfredo Fontanini, co-director of the Stony Brook University Neurosciences Institute, and a Department of Biology undergrad – was supported by grants from the National Institutes of Health and the NIH’s National Institute for Neurological Disease and Stroke.
Maffei, the paper’s senior author, suggested the grants were well spent, with the study opening the door to new avenues of thought on behavior and memory.
“These results link reduced communication between the taste and threat-processing centers (of the brain) to a change in taste preference,” the professor said in a statement. “[That] shows that changes in communication between brain centers can influence the way animals perceive and behave toward things that make them feel good or bad.”