Bending time: decoding rhythm adaptation in neural circuits
summary: A new study has revealed a key mechanism in how the brain adapts to the different pace of life.
Using Alston’s singing mouse, known for its variable vocalizations, the research team explored the role of the orofacial motor cortex in regulating the rhythm of song. Their findings revealed a process called ‘chronometry’, in which neurons adjust timing intervals, providing insight into the brain’s plasticity in vocal communication and behaviour.
This discovery paves the way for understanding how our brains enable diverse interactions with the world, with wide-ranging implications for technology, education, and therapy.
- The research focused on how the orofacial motor cortex of Alston’s singing rats adjusts the tempo of their vocalizations.
- Neurons in this brain area engage in “chronometry,” changing timing intervals rather than keeping track of absolute time.
- This mechanism highlights the brain’s ability to adapt, which may impact fields from neuroscience to technology.
Life has a challenging pace. Sometimes, it moves faster or slower than we would like. However, we adapt. We pick up the rhythm of conversations. We keep up with the crowds walking down the city sidewalk.
“There are many instances where we have to do the same action but at a different pace. The question is how the brain does it,” says Cold Spring Harbor Laboratory Assistant Professor Arkaroop Banerjee.
Now, Banerjee and his colleagues have uncovered new evidence suggesting that the brain adjusts our time processing to suit our needs. This is thanks in part to a noisy creature from Costa Rica called Alston’s singing rat.
This particular breed is known for its vocalizations that are audible to humans, lasting several seconds. One rat will sing the cry of longing, and the other will respond with a tune of its own. It is worth noting that the song varies in length and speed. Banerjee and his team sought to determine how neural circuits in the brains of mice control the tempo of their song.
The researchers pretended to engage in duets with mice while analyzing an area of their brains called the orofacial motor cortex (OMC). They recorded the activity of the neurons over several weeks. Then they looked for differences between songs with distinct durations and rhythms.
They found that OMC neurons engage in a process called temporal measurement. “Instead of encoding absolute time like a clock, neurons track something like relative time,” Banerjee explains. “They actually slow down or speed up the time interval. So, it’s not like a second or two, it’s 10%, 20%.
This discovery provides new insight into how the brain generates vocal communication. But Banerjee believes its effects go beyond language or music. It may help explain how time is calculated in other parts of the brain, allowing us to adjust different behaviors accordingly. This may tell us more about how our beautifully complex brains work.
“It’s this three-pound hunk of flesh that allows you to do everything from read a book to send people to the moon,” Banerjee says.
“It provides us with flexibility. We can change quickly. We adapt. We learn. If everything were stimulus and response, with no opportunity to learn, nothing to change, or long-term goals, we wouldn’t need a mind. We believe the cortex exists To add flexibility to behavior.
In other words, it helps make us who we are. Banerjee’s discovery may bring science closer to understanding how our brains enable us to interact with the world. The potential impacts of technology, education, and therapy are as limitless as our imagination.
About this neuroscience research news
author: Sarah Giarnieri
communication: Sarah Giarnieri – CSHL
picture: Image credited to Neuroscience News
Original search: Closed access.
“Temporal measurement of motor cortical dynamics reveals hierarchical control of vocal production” by Arkarup Banerjee et al. Normal neuroscience
Temporal measurement of motor cortical dynamics reveals hierarchical control of vocal production
Neocortical activity is thought to mediate voluntary control of sound production, but the underlying neural mechanisms remain unclear. In one vocal rodent, the male Alston singing rat, we studied neural dynamics in the orofacial motor cortex (OMC), a structure important for vocal behavior.
We first describe neural activity that is modulated by component feedback (~100 ms), which probably represents sensory feedback. However, at longer timescales, OMC neurons show diverse and often persistent locomotor firing patterns that stretch or compress with song duration (∼10 s). Using computer modeling, we have demonstrated that this time scale, operating through final motor output circuits, can enable acoustic flexibility.
These results provide a framework for studying hierarchical control circuits, a common design principle across many natural and artificial systems.