Researchers at Academia Sinica’s Institute of Molecular Biology have found that defects in particular neuronal circuits can induce autistic characteristics, a breakthrough discovery toward a potential clinical treatment for the disorder, which has also been proposed by the study.
Autism is a disorder becoming increasingly prevalent in highly developed countries, with its incidence estimated in 2012 to be one in 88 children in the US, and boys are five times more likely than girls to be diagnosed with an autism spectrum disorder (ASD).
ASDs are now known to be caused by early abnormal neural development, and while clinical studies have found an association with neural circuit formation, the molecular mechanism at work remained unclear, the team said.
Recent genome sequencing studies of ASDs have identified hundreds of mutated genes in people with the disorder, and the knowledge could be the first step in unveiling the pathogenesis of ASDs.
However, how disruptive mutations of genes lead to abnormal neural development, and thereby autism, is an unanswered question.
After nine years of research, lead author of study, Hsueh Yi-ping (薛一蘋), and her team found that insufficiency of the Tbr1 gene — one of the six most targeted genes with recurrent mutations identified in people with autism — results in defective axonal projections of amygdala neurons in mice, which acted differently from their wild-type counterparts in social interaction.
Hsueh said that mice with deficient Tbr1 were found to be missing “the posterior part of the anterior commissure” in their brains, which is the part responsible for connecting the two amygdalae in the two hemispheres of the brain.
“Not only was the connection between the two amygdalae impaired, the intra-amygdalar connections were also reduced,” Hsueh said.
The amygdala, an almond-shaped set of nuclei, is the region of the brain in charge of social interaction, emotional response, fear and aggression, the research team said.
The study found that mice with insufficient Tbr1 and reduced inter and intra-amygdala connectivity displayed autism-like behavior.
Researchers successfully ameliorated the behaviors by giving those animals D-cycloserine, an antibiotic that was at first used to fight Mycobacterium tuberculosis, but was later found to be helpful for treating a range of psychiatric ailments.
Hsueh said that although the missing posterior part of the anterior commissure cannot be restored, as it is a developmental defect, D-cycloserine could increase the activity of amygdalar neurons and ameliorate the mice’s autism-like behavior.
As D-cycloserine is a medication that is currently already in use clinically, its potential to be used for treatment of ASDs in the near future will be higher, if its related therapeutic effect is verified by further studies,” Hsueh said.
The team’s study has been published in the journal Nature Neuroscience.
Taiwan yesterday expelled four China Coast Guard vessels that entered Taiwan-controlled restricted waters off Lienchiang County (Matsu) shortly after the Chinese People’s Liberation Army announced the start of its “Joint Sword-2024B” drills around Taiwan. The Coast Guard Administration (CGA) said in a statement that it had detected two China Coast Guard ships west of Nangan Island (南竿) and another two north of Dongyin Island (東引) at 8am yesterday. After Chinese ships sailed into restricted waters off Matsu shortly afterward, the CGA’s Kinmen-Matsu-Penghu Branch deployed four patrol vessels to shadow and approach the vessels, it said. The incidents pushed up to 44 the number
Renovations on the B3 concourse of Taipei Main Station are to begin on Nov. 1, with travelers advised to use entrances near the Taiwan Railway or high-speed rail platforms or information counter to access the MRT’s Red Line. Construction is to be completed before the end of next year, Taipei Rapid Transit Corp said last week. To reduce the impact on travelers, the NT$95 million (US$2.95 million) project is to be completed in four stages, it said. In the first stage, the hall leading to the Blue Line near the art exhibition area is to be closed from Nov. 1 to the end
Taipei’s Ximending (西門町) shopping area welcomed the most international visitors, followed by Taipei 101, Songshan Cultural and Creative Park and Yangmingshan National Park (陽明山國家公園), a list of the city’s most popular tourist attractions published by the Taipei Department of Information and Tourism showed. As of August, 69.22 million people had visited Taipei’s main tourism spots, a 76 percent increase from 39.33 million in the same period last year, department data showed. Ximending had 20.21 million visitors, followed by Taipei 101 at 8.09 million, Songshan Cultural and Creative Park at 6.28 million, Yangmingshan at 4.51 million and the Red House Theater (西門紅樓) in
The government has issued a deportation order for a Spanish fugitive, ordering him to leave the country within 10 days, as he is wanted by European authorities for allegedly operating a car rental scam. National Immigration Agency (NIA) officials yesterday said Salvador Alejandro Llinas Onate, 48, had been notified that he must leave Taiwan, as he was wanted for committing serious crimes. The Spaniard has been indicted by Italian prosecutors for allegedly leading a 30 million euros (US$32.74 million) car rental scam and setting up a fraudulent company in Trento, Italy. The deportation order is based on Article 18 of