TY - JOUR
T1 - Differential Maturation of Climbing Fiber Innervation in Cerebellar Vermis
AU - Nishiyama, Hiroshi
AU - Linden, David J.
PY - 2004/4/21
Y1 - 2004/4/21
N2 - Folding of the brain surface is a general morphological adaptation to maximize surface area in a limited cranial volume. Surface folding is present not only in the neocortex but also in the cerebellar cortex. This folding creates subdivisions of the cortical surface: the sulci, the gyri, and the straight bank region, which is interposed. Is cortical folding only the solution to a surface-volume problem or does it also confer functional differences on the subdivisions that are created by this geometry? Here we have used the innervation of Purkinje cells by climbing fibers as a model system to explore potential functional differences. Purkinje cells are innervated by multiple climbing fibers at birth but undergo an activity-dependent refinement, such that by postnatal day (P) 21, most are contacted by a single climbing fiber. Using whole-cell recording from slices of cerebellar vermis derived from juvenile (P18-25) or adult (P60-83) mice, we found that significantly more Purkinje cells in the sulcus were innervated by multiple climbing fibers than in the gyrus or bank subdivisions; however, the basic properties of climbing fiber-Purkinje cell EPSCs such as kinetics, amplitude, and paired-pulse ratio were similar across cortical subdivisions. To search for a morphological correlate of differential multiple climbing fiber innervation, we labeled climbing fibers and performed reconstructions of immunofluorescent images. These revealed that, unlike the bank-gyrus subdivisions, most of the climbing fibers in the sulcus do not innervate the superficial molecular layer. These findings suggest that the subdivisions of the cerebellar cortex produced by folding may create functionally distinct entities.
AB - Folding of the brain surface is a general morphological adaptation to maximize surface area in a limited cranial volume. Surface folding is present not only in the neocortex but also in the cerebellar cortex. This folding creates subdivisions of the cortical surface: the sulci, the gyri, and the straight bank region, which is interposed. Is cortical folding only the solution to a surface-volume problem or does it also confer functional differences on the subdivisions that are created by this geometry? Here we have used the innervation of Purkinje cells by climbing fibers as a model system to explore potential functional differences. Purkinje cells are innervated by multiple climbing fibers at birth but undergo an activity-dependent refinement, such that by postnatal day (P) 21, most are contacted by a single climbing fiber. Using whole-cell recording from slices of cerebellar vermis derived from juvenile (P18-25) or adult (P60-83) mice, we found that significantly more Purkinje cells in the sulcus were innervated by multiple climbing fibers than in the gyrus or bank subdivisions; however, the basic properties of climbing fiber-Purkinje cell EPSCs such as kinetics, amplitude, and paired-pulse ratio were similar across cortical subdivisions. To search for a morphological correlate of differential multiple climbing fiber innervation, we labeled climbing fibers and performed reconstructions of immunofluorescent images. These revealed that, unlike the bank-gyrus subdivisions, most of the climbing fibers in the sulcus do not innervate the superficial molecular layer. These findings suggest that the subdivisions of the cerebellar cortex produced by folding may create functionally distinct entities.
KW - Bank
KW - Dendrite
KW - Multiple innervation
KW - Purkinje cell
KW - Sulcus
KW - Surface folding
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U2 - 10.1523/JNEUROSCI.5610-03.2004
DO - 10.1523/JNEUROSCI.5610-03.2004
M3 - Article
C2 - 15102908
AN - SCOPUS:2142707242
SN - 0270-6474
VL - 24
SP - 3926
EP - 3932
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 16
ER -