2 TYPES OF CALCIUM RESPONSE LIMITED TO SINGLE SPINES IN CEREBELLAR PURKINJE-CELLS

Citation
W. Denk et al., 2 TYPES OF CALCIUM RESPONSE LIMITED TO SINGLE SPINES IN CEREBELLAR PURKINJE-CELLS, Proceedings of the National Academy of Sciences of the United Statesof America, 92(18), 1995, pp. 8279-8282
Citations number
16
Categorie Soggetti
Multidisciplinary Sciences
ISSN journal
00278424
Volume
92
Issue
18
Year of publication
1995
Pages
8279 - 8282
Database
ISI
SICI code
0027-8424(1995)92:18<8279:2TOCRL>2.0.ZU;2-8
Abstract
Of fundamental importance in understanding neuronal function is the un ambiguous determination of the smallest unit of neuronal integration. It was recently suggested that a whole dendritic branchlet, including tens of spines, acts as the fundamental unit in terms of dendritic cal cium dynamics in Purkinje cells. By contrast, we demonstrate that the smallest such unit is the single spine. The results show, by two-photo n excited fluorescence laser scanning microscopy, that individual spin es are capable of independent calcium activation. Moreover, two distin ct spine populations were distinguished by their opposite response to membrane hyperpolarization. Indeed, in a subpopulation of spines calci um entry can also occur through a pathway other than voltage-gated cha nnels. These findings challenge the assumption of a unique parallel fi ber activation mode and prompt a reevaluation of the level of function al complexity ascribed to single neurons.