Brain Development, Plasticity, and Behavior by Bryan Kolb felt that the anatomical effects and behavioral effects were associated with damage to an infant’s brain. Over a half a million people in the world suffer from brain injury a year. These injuries can lead to permanent disorders in perception, movement, language, and personality. (Kolb, 1989) There were several approaches in his research. The first approach was studying the operations of a normal brain.
The second was to study behavioral patterns of a dysfunctional brain in order to compare it to that of a normal brain, and the third was to see if you could alter a brain in the middle of its development to see how the changes occur. There were two cases where women had severe head injuries and they injured the same areas of their brain, but their brains did not function the same. The study was to find out how they were different though the injuries were the same. There were several experiments conducted on rats to determine how this happens.
The rats fell into the three groups as mentioned earlier. Some of the rats had their neocortexes removed. These were removed at different ages of the rats. This was to make it similar to the procedure used on children with use of only one hemisphere of their brain. They found these to have similar impacts, and that the ability to control their limbs were lacking. They then put rats in a tank of water that had a platform for escape. The rats that had the procedure done as adults did significantly worse than the rats that had it at a younger age.
It has been concluded that there are many actors that influence how the rat or human will respond, these being IQ, personality, and handiness. The scientists also did a behavioral experiment by putting an electric prod in the rat’s home. The rats at a younger age during surgery buried the prod in saw dust and avoided getting shocked. The rats that were done at middle age avoided the prod, but did not bury it, while the adult surgical rats failed to do either and eventually had a conditioned response to avoid it. The studies show that early brain injury has different effects than a late brain injury.
It is difficult to measure how drastic it is, due to the behavior of the person that was injured as to how their body will adapt to the change, and third, despite the difference in change there is a strong correlation between dendritic arboration and behavioral recovery. Brain Plasticity and Behavior by Bryan Kolb states that Brain plasticity is the ability for the brain to change in order to function. In the review it was states that experience produces changes in the brain, and that neurons are affected by stress, pathology, and other factors. (Kolb B. 1998)
There are three behavioral distinctions the first is between exercise and skill acquisition second is voluntary movements and supported reactions, and the third is recovery and compensation. With experiments using rats, scientists have discovered that the more changes that occur in the brain, the weight of the brain changes. There has also shown changes in the neurons as well. With movement and voluntary reactions, rats have shown that when they had injections into a limb to disable it, when the rat reaches for food it uses the motor cortex to balance out its weight evenly between the other limbs.
Humans only have two, therefor making it harder for them to learn how to adapt to the shifting of weight as easily as the rats would. When a brain injury occurs, scientists have come to believe after observation of recovering rats that the rat is not actually recovering but a substitution of new movements to replace the lost movements. This tells them that the injury is not due to the neurons that didn’t die assuming the role of the lost neurons, but that the neurons are changing to compensate thus taking on the roles of the lost neurons as well as their own.
Evidence has shown that the brain plasticity and behavioral change are strongly linked together. There is very little evidence that shows that the human brain is capable of growing over a distance, but that the brain can heal itself to make it useful, though not ever to its full potential. The Plasticity of Human Maternal Brain: Longitudinal Changes in Brain Anatomy During Early Postpartum Period by Kim, Leckman, Mayes, Feldman, and Wang have determined that changes do occur in the maternal brain during the post-partum time frame in several areas.
Since the maternal care is the foundation for an infant’s development, it is found their brains to be important toward the infant’s behavior. These changes are used to experience parental behaviors. The study was conducted with nineteen mothers with a mean age of 33. All were right handed, Caucasian, married, and breastfeeding. All scored below 13 on the Beck Depression inventory. Interviews were conducted at home visits at 2-4 weeks postpartum. (Kim, 2010) There were all positive feedbacks on infants and parenthood. Next they conducted grey matter test both at 2-4 weeks postpartum and at 3 to 4 months postpartum.
The studies showed an increase in the amount of grey matter from each of the checkups. Several other things play a part in the amount of grey matter such as estrogen, oxytocin, and prolactin. The changes in the hormones in the brain also are changes in the anatomy as well. By comparing the maternal women to the other women with no children that are their age, shows that learning is occurring in the new mothers. It is suggested that there be further studies into this because the scale is on a smaller size, and should be tested with a larger group.
It is determined that the increase of grey matter is important in this stage of an infant’s life due to the fact the mother is learning how to care for the infant which is best for the structural development of the child. It would be in best interest to study other areas of change as well to determine just how much of the mother is affected when a child comes. Things such as environment, genetic or mood disorders may have an impact on the development of the maternal brain as well and should be considered in later studies.
Cognative Development in Children Born Preterm: Implications for Theories of Brain Plasticity Following Early Injury by Monica Luciana says relevant experiences to includebrain injury alter the brain in aprocess called Plasticity. The review is to discuss the outcome of plasticity through preterm labor in children. If a child is born before 37 weeks they are considered preterm. Since medicine has gotten better and the survival rate of a preterm baby has increased more than 40% since 1971. (Luciana, 2003) The developmental rate however has not improved.
Brain injuries were linked to low oxygen supply until recently, now they are realizing that it is also related to intrauterine infections. Much of the research on this has been conducted by Bryan Kolb (as mentioned earlier) with his experimentation with rats. Based on his controlled experiments and on lab experiments with monkeys there have been several predictions made about neonatal challenges. Neuromigration occurs in the last trimester. Therefor if the infant is born too early the outcome of the cognitive development would be lower than that of a full term infant.
A human infant though is more ill prepared, because they did not come from a laboratory where rats have been monitor, therefore behavioral functions are not accurately assessed. The gross motor and fine motor skills are assessed by comparing a group of preterm infants to a group of full term infants in a controlled experiment assessing their memory and skills. Studies have shown increase in white matter and atrophy as well as global delays. AS the children get older the IQ of the children are tested.
There are minimal differences due to the plasticity over time changing the makeup of the brain in order to make up for the damage that has been done. The brain continues to show damage from being a preterm infant, though through test results it is hard to identify. It is proven that the preterm babies doing fact show higher levels of mental retardation that a full term baby. They also score lower on intellectual testing. Recovery may not be evident until adulthood, minor neuro abnormalities can in fact fix themselves through plasticity to reroute.
Majority of all these experiments were conducted in a laboratory setting, if done in an actual life setting results may vary. Other variables such as environment and genetics play a part in the upbringing and conditioning of the brain in order for it to manifest itself into something more sufficient. Pain, Plasticity, and Premature Birth: A Prescription for Permanent Suffering? By K. J. S. Anand is a collection of studies that was put together in order to determine if any pain that has occurred during the neonatal time frame can lead to long-term behavior problems, if the infant cannot remember it actually happening.
Since thousands of newborns a year have invasive surgery some without any pain relief, Anand believes that this pain occurred can have an impact in the adult life regardless of if it is remember or not. (Anand, 2000) It is believed that the pain is kept in your procedural memory and can lead to behavioral problems. In multiple experiments on rats, they are injected in a hind paw while they are only a few days old that will inflame their leg for a week. Though rats do not primarily have sensory output through their sciatic nerve, the rats that had the injection showed nerve response as adults in the sciatic nerve.
When there is a neonatal skin wound, it creates a reflex in nerve fibers lowering the pain threshold for several weeks after the injury. Results similar to those of the rats can be seen in infants as well. Studies have shown that babies that where given pain medicine right before circumcision compared to babies that were not show different behavior responses when receiving vaccinations. This study however is partially inconclusive due to the fact that in order to create the same experiment given to a rat, to a human, could cause permanent damage.
Because of the life expectancy, the weeklong pain given to a rat would be compared to several weeks of pain in a baby. By prolonging an inflammation that long can cause permanent damage to include fibrosis, limb deformities, and changes in the spinal cord. These types of studies are rarely performed in a lab setting. By measuring the facial responses of an infant that has undergone several procedures, it can be proven that they have a lessened response to things such as a heel lance for blood work. A preterm child is less susceptible to pain than a full term child due to the time spent in the NICU.
Due to plasticity taking over to reroute the brain from the painful experience that is caused, abnormal behaviors can occur into adulthood. Due to the results of the entire lab test in it is clear that the painful experiences will be remembered in some part of the brain that stores it the entire life of the individual. This should be brought to the attention of the caregivers in order to better assess what is relevant to be done due to the long term impact that it causes. The price to pay for medical procedures to keep the baby alive will in turn be paid in therapy when the child is older.
New therapeutic strategies should be considered in the process of the work that needs to be done on the infant to keep it alive. Local Anesthetic Treatment Significantly Attenuates Acute Pain Responding But Does Not Prevent the Neonatal Injury- Induced Reduction In Adult Spinal Behavioral Plasticity by Young, Baumbauer, Hillyer, and Joynes says that there are finding that show that neonatal injury in adult subject have decreased spinal plasticity. There are many treatments for diagnostics in newborns that cause strong responses to pain, and that they are usually preformed without any analgesics.
They tend to also cause tissue damage. Though adults do not remember experiencing the pain of procedures that incurred while they were infants it can go through adulthood with neurological responses. (Young, 2008) Through Plasticity the spinal cord can change as a result of shock that is continuous. While testing with rats, there were two groups. One group was injected with Lidocaine, while the other group was not. The rats were 3 days old making them equivalent to a newborn infant. There was pain administered the back paw several times. A reflexive response was given by both rats through nerves.
The rats that were not given the Lidocaine started having a conditioned response to move before it was even touched. When the rats became adults, the rats that were given the Lidocaine had only reflexive responses when touched on the hind legs as they were as a pup. The rats that were left un-numbed to the pain had a conditioned response still to move before it was even touched. Though there was not pain being administered to the area, the rats still tried to move out of the way. The injured rats had a lower threshold for pain than the uninjured rats did. The medical community rests undecided on the pain management for infants.
Because there are opiates and narcotics administered to adult to help alleviate pain, the risks for giving them to infants are way too high. This leads to only local anesthetics to be administered to infants. After all surgeries the inflammation will cause pain, but there is only so much that can be done in the form of drugs for infants, and until they can devise a change, nothing will change. It is clear that neonatal injuries have an effect on the spinal plasticity.
Further studies need to be taken into account, and an intervention needs to be capable of reducing the effects on n injury in infants during their most vulnerable stages in life. I chose to do my paper on Brain Plasticity because I think that this is something important that happens in the brain. It is very neat how the body can adapt to injury and try to rebuild itself despite the trauma. Though it cannot heal itself as well as if the injury never occurred, the fact that a person can still function is incredible. There are many different reviews dealing with Plasticity, but I have gathered that the younger you are when injury occurs, the easier the brain can fix itself. This goes to prove the theory on children being resilient.