Abstract
Specifying synaptic partners and regulating synaptic numbers are at least partly activity-dependent processes during visual map formation in all systems investigated to date [1-5]. In Drosophila, six photoreceptors that view the same point in visual space have to be sorted into synaptic modules called cartridges in order to form a visuotopically correct map [6, 7]. Synapse numbers per photoreceptor terminal and cartridge are both precisely regulated [8-10]. However, it is unknown whether an activity-dependent mechanism or a genetically encoded developmental program regulates synapse numbers. We performed a large-scale quantitative ultrastructural analysis of photoreceptor synapses in mutants affecting the generation of electrical potentials (norpA, trp;trpl), neurotransmitter release (hdc, syt), vesicle endocytosis (synj), the trafficking of specific guidance molecules during photoreceptor targeting (sec15), a specific guidance receptor required for visual map formation (Dlar), and 57 other novel synaptic mutants affecting 43 genes. Remarkably, in all these mutants, individual photoreceptors form the correct number of synapses per presynaptic terminal independently of cartridge composition. Hence, our data show that each photoreceptor forms a precise and constant number of afferent synapses independently of neuronal activity and partner accuracy. Our data suggest cell-autonomous control of synapse numbers as part of a developmental program of activity-independent steps that lead to a "hard-wired" visual map in the fly brain.
| Original language | English |
|---|---|
| Pages (from-to) | 1835-1843 |
| Number of pages | 9 |
| Journal | Current Biology |
| Volume | 16 |
| Issue number | 18 |
| DOIs | |
| State | Published - Sep 19 2006 |
| Externally published | Yes |
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Keywords
- MOLNEURO
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
Cite this
Activity-Independent Prespecification of Synaptic Partners in the Visual Map of Drosophila. / Hiesinger, P. Robin; Zhai, Rong G; Zhou, Yi; Koh, Tong Wey; Mehta, Sunil Q.; Schulze, Karen L.; Cao, Yu; Verstreken, Patrik; Clandinin, Thomas R.; Fischbach, Karl Friedrich; Meinertzhagen, Ian A.; Bellen, Hugo J.
In: Current Biology, Vol. 16, No. 18, 19.09.2006, p. 1835-1843.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Activity-Independent Prespecification of Synaptic Partners in the Visual Map of Drosophila
AU - Hiesinger, P. Robin
AU - Zhai, Rong G
AU - Zhou, Yi
AU - Koh, Tong Wey
AU - Mehta, Sunil Q.
AU - Schulze, Karen L.
AU - Cao, Yu
AU - Verstreken, Patrik
AU - Clandinin, Thomas R.
AU - Fischbach, Karl Friedrich
AU - Meinertzhagen, Ian A.
AU - Bellen, Hugo J.
PY - 2006/9/19
Y1 - 2006/9/19
N2 - Specifying synaptic partners and regulating synaptic numbers are at least partly activity-dependent processes during visual map formation in all systems investigated to date [1-5]. In Drosophila, six photoreceptors that view the same point in visual space have to be sorted into synaptic modules called cartridges in order to form a visuotopically correct map [6, 7]. Synapse numbers per photoreceptor terminal and cartridge are both precisely regulated [8-10]. However, it is unknown whether an activity-dependent mechanism or a genetically encoded developmental program regulates synapse numbers. We performed a large-scale quantitative ultrastructural analysis of photoreceptor synapses in mutants affecting the generation of electrical potentials (norpA, trp;trpl), neurotransmitter release (hdc, syt), vesicle endocytosis (synj), the trafficking of specific guidance molecules during photoreceptor targeting (sec15), a specific guidance receptor required for visual map formation (Dlar), and 57 other novel synaptic mutants affecting 43 genes. Remarkably, in all these mutants, individual photoreceptors form the correct number of synapses per presynaptic terminal independently of cartridge composition. Hence, our data show that each photoreceptor forms a precise and constant number of afferent synapses independently of neuronal activity and partner accuracy. Our data suggest cell-autonomous control of synapse numbers as part of a developmental program of activity-independent steps that lead to a "hard-wired" visual map in the fly brain.
AB - Specifying synaptic partners and regulating synaptic numbers are at least partly activity-dependent processes during visual map formation in all systems investigated to date [1-5]. In Drosophila, six photoreceptors that view the same point in visual space have to be sorted into synaptic modules called cartridges in order to form a visuotopically correct map [6, 7]. Synapse numbers per photoreceptor terminal and cartridge are both precisely regulated [8-10]. However, it is unknown whether an activity-dependent mechanism or a genetically encoded developmental program regulates synapse numbers. We performed a large-scale quantitative ultrastructural analysis of photoreceptor synapses in mutants affecting the generation of electrical potentials (norpA, trp;trpl), neurotransmitter release (hdc, syt), vesicle endocytosis (synj), the trafficking of specific guidance molecules during photoreceptor targeting (sec15), a specific guidance receptor required for visual map formation (Dlar), and 57 other novel synaptic mutants affecting 43 genes. Remarkably, in all these mutants, individual photoreceptors form the correct number of synapses per presynaptic terminal independently of cartridge composition. Hence, our data show that each photoreceptor forms a precise and constant number of afferent synapses independently of neuronal activity and partner accuracy. Our data suggest cell-autonomous control of synapse numbers as part of a developmental program of activity-independent steps that lead to a "hard-wired" visual map in the fly brain.
KW - MOLNEURO
UR - http://www.scopus.com/inward/record.url?scp=33748453391&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33748453391&partnerID=8YFLogxK
U2 - 10.1016/j.cub.2006.07.047
DO - 10.1016/j.cub.2006.07.047
M3 - Article
C2 - 16979562
AN - SCOPUS:33748453391
VL - 16
SP - 1835
EP - 1843
JO - Current Biology
JF - Current Biology
SN - 0960-9822
IS - 18
ER -