title: Differential regulation of Purkinje cell dendritic spines in rolling mouse Nagoya (tg/tg), P/Q type calcium channel (α1(A)/Ca(v)2.1) mutant.
abstract: Voltage dependent calcium channels (VDCC) participate in regulation of neuronal Ca(2+). The Rolling mouse Nagoya (Cacna1a(tg-rol)) is a spontaneous P/Q type VDCC mutant, which has been suggested as an animal model for some human neurological diseases such as autosomal dominant cerebellar ataxia (SCA6), familial hemiplegic migraine and episodic ataxia type-2. Morphology of Purkinje cell (PC) dendritic spine is suggested to be regulated by signal molecules such as Ca(2+) and by interactions with afferent inputs. The amplitude of excitatory postsynaptic current was decreased in parallel fiber (PF) to PC synapses, whereas apparently increased in climbing fiber (CF) to PC synapses in rolling mice Nagoya. We have studied synaptic morphology changes in cerebella of this mutant strain. We previously found altered synapses between PF varicosity and PC dendritic spines. To study dendritic spine plasticity of PC in the condition of insufficient P/Q type VDCC function, we used high voltage electron microscopy (HVEM). We measured the density and length of PC dendritic spines at tertiary braches. We observed statistically a significant decrease in spine density as well as shorter spine length in rolling mice compared to wild type mice at tertiary dendritic braches. In proximal PC dendrites, however, there were more numerous dendritic spines in rolling mice Nagoya. The differential regulation of rolling PC spines at tertiary and proximal dendrites in rolling mice Nagoya suggests that two major excitatory afferent systems may be regulated reciprocally in the cerebellum of rolling mouse Nagoya.
authors.affiliation: Laboratory of Animal Management, School of Agricultural Science, Nagoya University, Nagoya, Japan.
authors.forename: Sen-Ich
authors.initials: SI
authors.lastname: Oda
authors.forename: Kea Joo
authors.initials: KJ
authors.lastname: Lee
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Arii
authors.forename: Keiji
authors.initials: K
authors.lastname: Imoto
authors.forename: Byung-Hwa
authors.initials: BH
authors.lastname: Hyun
authors.forename: In Sung
authors.initials: IS
authors.lastname: Park
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Im Joo
authors.initials: IJ
authors.lastname: Rhyu