Comparison of plasticity in sensory and cognitive processing systems.
The term "brain plasticity" can be applied to a number of processes, each with its own set of complex mechanisms. The plasticity of the human brain during postnatal development has been contrasted for a sensory, i.e., auditory, and cognitive system by comparing the development of two different evoked potential components. The short-latency auditory brainstem responses (ABRs), which are generated by auditory neurons within the brainstem auditory pathway, are mature by 1 to 2 years after birth. The rate of ABR development, as shown by longitudinal recordings from preterm infants, appears to be equally rapid in intrauterine and extrauterine environments. In contrast, the long-latency P300 cognitive potential, which reflects such processes as sequential information processing and short-term memory, does not show a mature waveform and latency until 14 to 17 years of age. This protracted rate of development cannot yet be related to a brain substrate, as the generator origins of the P300 are unknown. Clinical and animal data suggest, however, that limbic structures are critically involved. The long developmental history of the P300, in contrast to the ABRs, provides a functional measure of developmental plasticity in a cognitive versus a sensory brain system.
Buchwald
J S
JS
Department of Physiology, UCLA School of Medicine.
D000293:Adolescent; D000328:Adult; D000818:Animals; D001921:Brain / Q000254:growth & development*; D002415:Cats; D002648:Child; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology; D009473:Neuronal Plasticity