Trends in Neurosciences
ReviewRecovery recapitulates ontogeny
Section snippets
Motor performance
For several decades, researchers have described behavioral parallels between the successive stages of normal development and recovery from brain injury. For example, Hines showed that the normal development of locomotion and posture in rhesus monkeys passed through states similar to those seen during stroke recovery4. Teitelbaum et al. found that the four stages of feeding behavior in normal development re-emerged in rats recovering from a lateral hypothalamic injury5. Other studies from his
Bilateral motor control
Childhood is associated with bilateral motor control, in association with immaturity of the corticospinal connections that are essential for fractionated unilateral movements. In contrast, adulthood is associated primarily with contralateral motor control, together with well-developed corticospinal tract size and function10, 11. Muller et al.12 found that transcranial magnetic stimulation of motor cortex induced bilateral responses in hand and arm muscles of most children, but only
Cortical-map plasticity
Brain-mapping studies have supported the idea that in humans, a number of cortical regions contain orderly but overlapping representation of body regions29, 30. In animal studies, these maps show a degree of redundancy and overlap31, a finding also described in human brain-mapping studies32. The capacity to reorganize cortical representational maps might be maximal at early time points in development. For example, hemispherectomy during early childhood can be associated with remapping of motor,
Re-emergence of molecular and cellular developmental events
Developmental proteins normally absent or present at very low levels in adult brain re-emerge after an ischemic brain insult, often at a time of limited cellular metabolic resources. A wide range of proteins have been described, many focused in the penumbral area surrounding an infarct and some appearing in bilateral hemispheres (Fig. 2). Increased proteins levels after stroke are related to changes in the extracellular matrix, glial structure, neuronal growth, apoptosis, angiogenesis and
Clinical approaches
The analogy between development and stroke recovery could suggest clinical approaches to maximize patient outcomes. NMDA-receptor block is a strategy employed in many current therapeutic trials of acute ischemic stroke. However, during development, such inhibition is associated with reduced dendritic and synaptic pruning61, 62, 63. Similarly, during stroke recovery, NMDA-receptor antagonism is also associated with prevention of dendritic pruning and increased behavioral deficits64, 65. Levels
Concluding remarks
In 1866, Haeckel proposed that ontogeny recapitulates phylogeny. Some elements of his theories have been of heuristic value. In recent decades, a number of researchers have recognized parallels that exist between stroke recovery and ontogeny, with examples described at the behavioral, brain mapping, cellular and molecular levels. Animal studies have identified treatments that improve long-term outcome by targeting the events that underlie stroke recovery53, 59, 72, 78. Parallels with
Acknowledgements
The authors thank Denice Bliesath for manuscript preparation. The authors’ research is supported by the NICHHD grant K08 HD1219 (S.C.) and NINDS grants PO1 NS23393 and RO1 NS33627 (M.C.).
References (91)
Brain representation of active and passive movements
Neuroimage
(1996)Contralateral and ipsilateral EMG responses to transcranial magnetic stimulation during recovery of arm and hand function after stroke
Electroenceph. Clin. Neurophys.
(1996)Reemergence of the fetal pattern of L-type calcium channel gene expression in non infarcted myocardium during left ventricular remodeling
Biochem. Biophys. Res. Commun.
(1995)Regulation of hepatic expression of IGF I and fetal IGF binding protein mRNA in streptozotocin-diabetic rats
FEBS Lett.
(1989)Sequence of expression of MyoD1 and various cell surface and cytoskeletal proteins in regenerating mouse muscle fibers following treatment with sodium dihydrogen phosphate
J. Neurol. Sci.
(1999)Changes in synaptic density in motor cortex of rhesus monkey during fetal and postnatal life
Dev. Brain Res.
(1989)- et al.
Overgrowth and pruning of dendrites in adult rats recovering from neocortical damage
Brain Res.
(1992) Synaptogenesis and dendritic growth in the cortex opposite unilateral sensorimotor cortex damage in adult rats: a quantitative electron microscopic examination
Brain Res.
(1996)Recovery of upper extremity function in stroke patients: the Copenhagen stroke study
Arch. Phys. Med. Rehabil.
(1994)- et al.
The role of NMDA receptors and nitric oxide in retinogeniculate development
Prog. Brain Res.
(1996)