As reported by Medical Research News, veterinary researchers at the University of California, Davis, are teaming up with their colleagues in human medicine to investigate a troubling disorder in newborn horses and are exploring possible connections to childhood autism. The common link, the researchers suggest, may be abnormal levels of naturally occurring neurosteroids.
Shaky first steps of newborn foal
Veterinary researchers at the University of California, Davis, are teaming up with their colleagues in human medicine to investigate a troubling disorder in newborn horses and are exploring possible connections to childhood autism.
© 2012 by April Raine
The horse disorder, known as neonatal maladjustment syndrome, has puzzled horse owners and veterinarians for a century. Foals affected by the disorder seem detached, fail to recognize their mothers and have no interest in nursing.
"The behavioral abnormalities in these foals seem to resemble some of the symptoms in children with autism," said John Madigan, a UC Davis veterinary professor and expert in equine neonatal health.
The maladjustment syndrome in foals also caught the attention of Isaac Pessah, a professor of molecular biosciences at the UC Davis School of Veterinary Medicine and a faculty member of the UC Davis MIND Institute, who investigates environmental factors that may play a role in the development of autism in children.
"There are thousands of potential causes for autism, but the one thing that all autistic children have in common is that they are detached," Pessah said
Madigan, Pessah and other researchers in veterinary and human medicine recently formed a joint research group and secured funding to investigate links between the two conditions.
Maladjusted foal syndrome
In newborn foals, neonatal maladjustment syndrome, or dummy foal syndrome, occurs in 3 to 5 percent of live births. With around-the-clock bottle or tube feeding plus intensive care in a veterinary clinic for up to a week or 10 days, 80 percent of the foals recover. But for horse owners, that level of care is grueling and costly.
For years, the syndrome has been attributed to hypoxiaâinsufficient oxygen during the birthing process. Madigan and UC Davis veterinary neurologist Monica Aleman began sleuthing around for other potential causes, however, noting that hypoxia usually causes serious, permanent damage, while most foals with the maladjustment syndrome survive with no lingering health problems.
One of their prime suspects was a group of naturally occurring neurosteroids, which are key to sustaining pregnancies in horses, especially in keeping the foal "quiet" before birth.
"We believe that the pressure of the birth canal during the second stage of labor, which is supposed to last 20 to 40 minutes, is an important signal that tells the foal to quit producing the sedative neurosteroids and 'wake up,' " Madigan said.
Furthermore, the research team has found for the first time that sedative neurosteroids persist, and their levels often rise, in the bloodstream of foals born with symptoms of the maladjustment syndrome. These neurosteroids are known to be able to cross the blood-brain barrier and impact the central nervous system, acting on the same receptor as do sedatives and anesthetics.
Foal behaviors resemble autism
The early findings have compelling implications for the health of newborn foals, and have caused the researchers to also explore possible links to autism, which includes a group of complex brain-development disorders. While the symptoms vary, these disorders are generally marked by difficulties with social interactions, verbal and nonverbal communication, and repetitive behaviors.
"The concept that a disruption in the transition of fetal consciousness may be related to children with autism is intriguing," said Pessah, noting that the behaviors seen in the maladjusted foal syndrome truly are reminiscent of those in some autistic children.
He notes that some children with autism do outgrow autistic behaviors by the time they reach their teen years. Could this be a parallel to the recovery of the foals with the maladjustment syndrome?