Mysterious hair-like growth inside brain may be behind perception of time, study finds

Removal of antennae-like growth called cilia from some brain regions is linked to impaired time perception and judgment in mice, according to a new study.

The findings, published in the journal Molecular Neurobiology, suggest these hair-like growths may be potential new drug targets to treat conditions like schizophrenia, autism, and Parkinson’s disease.

The brain’s striatum region processes and integrates new environmental sensory information and coordinates the time sequence of motor responses.

It performs the body’s clock processes, essential in controlling executive functions, including coordination of limbs, learning, planning, decision-making, and working memory as well as attention, scientists, including those from the University of California - Irvine (UCI) in the US, explain.

Across many neurological disorders, they say, there is a profound decline in patients’ ability to accurately estimate the timing and termination of their actions.

In the new study, researchers uncovered the first evidence of the important roles the cilia play in such timing-dependent dysfunction.

“Our findings may revolutionize our understanding of brain functions and mental disorders in the context of the critical task performed by these previously unappreciated organelles in the brain’s ‘central clock’ function,” Amal Alachkar, a co-author of the study from UCI said in a statement.

“Our results may open new avenues for effective intervention through cilia-targeted therapies for treatment,” Dr Alachkar said.

Cilia are hair-like organelles that protrude from the brain cell surfaces like antennae.

Studies have shown that these growths work as signaling hubs, sensing and transmitting signals to generate appropriate reactions.

In the new research, scientists removed cilia from the striatum in mice using gene manipulation technology.

They found that these rodents were unable to learn new physical movement tasks and showed repetitive motor behavior as well as delays in decision-making.

Researchers say these mice were also deficient in rapidly recalling information about their location and orientation in space.

The mice were also unable to filter irrelevant environmental sensory information, the study noted, adding, however, that they could maintain already learned motor skills and long-term memories.

“Successful performance of working memory, attention, decision-making and executive function requires accurate and precise timing judgment, usually within a millisecond to a minute,” Dr Alachkar said.

“When that capacity is impaired, it means losing the ability to quickly adjust behavior in response to changes in external stimuli and failing to sustain appropriate, goal-oriented motor responses,” he added.

In further studies, scientists hope to understand the mechanisms by which cilia regulate time perception.

They also hope to develop targeted therapies that could improve some of these deficits.