title: Developmental change in the contribution of voltage-gated Ca(2+) channels to the pacemaking of deep cerebellar nuclei neurons.
abstract: The activity of the deep cerebellar nuclei (DCN) neurons conveys the bulk of the output of the cerebellum. To generate these motor signals, DCN neurons integrate synaptic inputs with their own spontaneous activity. We have previously reported that N-type voltage-gated Ca(2+) channels modulate the spontaneous activity of the majority of juvenile DCN neurons in vitro. Specifically, pharmacologically blocking N-type Ca(2+) channels increases their firing rate causing DCN cells to burst. Adult DCN neurons however, behaved differently. To further investigate this change, we have studied here the effect of cadmium on the firing rate of DCN neurons in acute cerebellar slices obtained from adult (>2 months old) or juvenile (12-21 days old) rats and mice. Strikingly, and in contrast to juvenile DCN cells, cadmium did not affect the pacemaking of adult DCN cells. The activity of Purkinje cells (PCs) however was transformed into high-frequency bursting, regardless the age. Further, we questioned whether these findings could be due to an artifact associated with the added difficulty of preparing adult DCN slices. Hence we proceeded to examine the spontaneous activity of DCN neurons in anesthetized juvenile and adult rats and mice in vivo. When cadmium was injected into the DCN in vivo no significant change in firing rate was observed, conversely to most juvenile DCN neurons which showed high-frequency bursts after cadmium injection. In these same animals, PCs pacemaking showed no developmental difference. Thus our results demonstrate a remarkable age-dependent functional modification in the regulation of DCN neurons pacemaking.
authors.affiliation: Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States. Electronic address: kalvina0308@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Alviña
authors.affiliation: Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Present address: Neurodegeneration Research Laboratory, Molecular Biology and Genetics Department, Bogazici University, Istanbul 34342, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Tara
authors.affiliation: Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
authors.forename: K
authors.initials: K
authors.lastname: Khodakhah
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001030:Apamin / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism*; D002529:Cerebellar Nuclei / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology*; D005260:Female; D008297:Male; D008810:Mice, Inbred C57BL; D008839:Microelectrodes; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010507:Periodicity; D017208:Rats, Wistar; D046509:Tissue Culture Techniques
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002104:Cadmium; D001030:Apamin
keywords: calcium channels; cerebellum; development; pacemaking