Research Article| Volume 18, ISSUE 3, P173-178, May 1996

Development of corticospinal tract fibers and their plasticity II. Neonatal unilateral cortical damage and subsequent development of the corticospinal tract in mice

      This paper is only available as a PDF. To read, Please Download here.


      In this study, the right cerebral cortices of mice on postnatal day 0 (P0) were cryocoagulated with dry ice. Subsequent development of the corticospinal tract (CST) was studied morphologically and quantitatively, and was compared with that in age-matched controls. When the pyramidal tract was traced anterogradely by injecting HRP into the sensorimotor area of the left cerebral cortex of adult operated mice, the right CST originating from the healthy left hemisphere showed remarkable hypertrophy. The number of axons in the CST at the C4–C6 level became maximum on P14 in the control mice and rapidly decreased thereafter. In the operated mice, the axonal number in the right CST also was maximal on P14 and then rapidly decreased. However, the decrease in axonal number after P21 was less in the operated mice than in the controls. Moreover, the number of axons showed a slight increase after P56. These results indicate that the physiological elimination of the parent axons and their collaterals is much lower in the operated mice than in the controls, and that the increase in axon collaterals from parent axons in the hypertrophic right CST persists a long time in the operated mice.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Brain and Development
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Hjern B
        • Nylander I
        Late prognosis of severe head injuries in childhood.
        Arch Dis Child. 1962; 37: 113-116
        • Tsukiyama T
        • Nakamura S
        • Hirayama T
        • Sasaki J
        • Tsubokura T
        Recovery process of motor disturbance in pediatric head injury (in Japanese).
        Shoni no Noshinkei (Kobe). 1983; 8: 93-100
        • Janowsky JS
        • Finlay BL
        The outcome of perinatal brain damage: the roˆle of normal neuron loss and axon retraction.
        Dev Med Child Neurol. 1986; 28: 375-389
        • Raisman G
        Neuronal plasticity in septal nuclei of the adult rat.
        Brain Res. 1969; 14: 25-48
        • Matthews DA
        • Cotman C
        • Lynch G
        An electron microscopic study of lesion-induced synaptogenesis in dentate gyrus of the adult rat. II. Reappearance of morphologically normal synaptic contacts.
        Brain Res. 1976; 115: 23-41
        • Nakamura Y
        • Mizuno N
        • Konishi A
        A quantitative electron microscope study of cerebellar axon terminals on the magnocellular red nucleus neurons in the cat.
        Brain Res. 1978; 147: 17-27
        • Cotman CW
        • Nieto-Sampedro M
        • Harris EW
        Synapse replacement in the nervous system of adult vertebrates.
        Physiol Rev. 1981; 61: 684-784
        • Cotman CW
        • Nieto-Sampedro M
        Cell biology of synaptic plasticity.
        Science. 1984; 225: 1287-1294
        • Steward O
        • Vinsant SL
        The process of reinnervation in the dentate gyrus of the adult rat: A quantitative electron microscopic analysis of terminal proliferation and reactive synaptogenesis.
        J Comp Neurol. 1983; 214: 370-386
        • Gorgels TGMF
        A quantitative analysis of axon outgrowth, axon loss, and myelination in the rat pyramidal tract.
        Dev Brain Res. 1990; 54: 51-61
        • Uematsu J
        • Ono K
        • Yamano T
        • Shimada M
        Development of corticospinal tract fibers and their plasticity. I: Quantitative analysis of the developing corticospinal tract in mice.
        Brain Dev. 1996; 18: 29-34
        • Ono K
        • Shimada M
        • Yamano T
        Reorganization of the corticospinal tract following neonatal unilateral cortical ablation in rats.
        Brain Dev (Tokyo). 1990; 12: 226-236
        • Ono K
        • Yamano T
        • Shimada M
        Formation of an ipsilateral corticospinal tract after ablation of cerebral cortex in neonatal rat.
        Brain Dev (Tokyo). 1991; 13: 348-351
        • Gribnau AAM
        • de Kort EJM
        • Dederen PJWC
        • Nieuwenhuys R
        On the development of the pyramidal tract in the rat. II An anterograde tracer study of the outgrowth of the corticospinal fibers.
        Anat Embryol. 1986; 175: 101-110
        • Joosten EAJ
        • van Eden CG
        An anterogradely tracer study on the development of corticospinal projections from the medial prefrontal cortex in the rat.
        Dev Brain Res. 1989; 45: 313-319
        • Kennard MD
        Age and other factors in motor recovery from precentral lesions in monkeys.
        Am J Physiol. 1936; 115: 138-146
        • Reh T
        • Kalil K
        Development of the pyramidal tract in the hamster. II An electron microscopic study.
        J Comp Neurol. 1982; 205: 77-88
        • Ivy GO
        • Killackey HP
        Ontogenetic changes in the projections of neocortical neurons.
        J Neurosci. 1982; 2: 735-743
        • Stanfield BB
        • O'Leary DDM
        The transient corticospinal projection from the occipital cortex during the postnatal development of the rat.
        J Comp Neurol. 1985; 238: 236-248
        • Stanfield BB
        The development of the corticospinal projection.
        Prog Neurobiol. 1992; 38: 169-202
        • Stanfield BB
        • O'Leary DDM
        • Fricks C
        Selective collateral elimination in early postnatal development restricts cortical distribution of rat pyramidal tract neurons.
        Nature (Lond). 1982; 298: 371-373
        • Joosten EAJ
        • Bar PR
        • Gispen WH
        Corticospinal axons and mechanism of target innervation in rat lumbar spinal cord.
        Dev Brain Res. 1994; 79: 122-127
        • Ono K
        • Watanabe Y
        • Ishizuka C
        • et al.
        Axon ramification following unilateral cortical ablation in neonatal rats.
        Brain Dev (Tokyo). 1994; 16: 264-266
        • Curfs MHJM
        • Gribnau AAM
        • Dederen PJWC
        Selective elimination of transient corticospinal projection in the rat cervical spinal cord gray matter.
        Dev Brain Res. 1994; 78: 182-190