FB2025_05 , released December 11, 2025
FB2025_05 , released December 11, 2025
CV Term Report
Help Close All Open All
General Information
Term columnar neuron T1 ID (Ontology) FBbt:00003727 (Fly Anatomy)
Definition An intrinsic columnar neuron whose cell body lies in the cortex of the medulla. The fiber of the T1 cell body branches at the medulla surface to form a T-shaped linking fiber between a bush-like arborization in the distal part of a medulla column (M1 and M2), and a bundle of climbing fibers in the equivalent column of the lamina (Fischbach and Dittrich, 1989). Synaptic connections in the lamina are exclusively postsynaptic and include a large number of connections from lamina intrinsic (amacrine) neurons (Meinertzhagen and O'Neil, 1991; Rivera-Alba et al., 2011). In the medulla, it is strongly synapsed by centrifugal neuron C3 in medulla layer M2 and lamina monopolar neuron L2 (Takemura et al., 2008; Takemura et al., 2013). There is usually one of these cells per optic column (Nern et al., 2025).[ FlyBase:FBrf0049410 FlyBase:FBrf0054529 FlyBase:FBrf0205531 FlyBase:FBrf0216925 FlyBase:FBrf0222324 FlyBase:FBrf0262545 ]
Also Known As "T neuron T1" ; "T1"
Comment Cell connectivity in the lamina was determined by analysis of semi-automated EM reconstruction of 749 serial sections of 21 complete lamina cartridges. The number of synaptic connections for T1 (presynaptic/postsynaptic) in a single lamina cartridge for each cell type was the following: R2 (-/2), R3 (-/2), R4 (-/2), Lai (-/54), C3 (-/1) and Lawf (-/1) (Rivera-Alba et al., 2011). Connectivity in the medulla was extrapolated from serial EM of 3 columns from a single sample (Takemura et al., 2008) or from 7 columns (Takemura et al., 2013).
Links to External Ontologies
VFB:FBbt_00003727
Annotations
Records annotated with this term OR any of its CHILD TERMS
Records annotated with this exact term (annotations to child terms are NOT included)
Data Class Field Records
Insertions (FBti)  EXPRESSION_STAGE_TISSUE_POSITION       5
show Full annotation statements including this term (annotations to child terms are NOT included), and relevant FlyBase records
 Full annotation statements 
Relevant FlyBase reports
 Alleles  Genes  Insertions Constructs
 columnar neuron T1 (all annotations which use CV term, excluding "NOT" statements)       4      5      1     19      5     15
Spanning Tree (Parents/Children)
Only view relationship:
adult optic lobe neuron
 |__optic lobe intrinsic columnar neuron____
adult optic lobe columnar neuron            |
 |__optic lobe intrinsic columnar neuron____|
adult optic lobe intrinsic neuron           |
 |__optic lobe intrinsic columnar neuron____|
secondary neuron                            |
 |__Notch OFF hemilineage secondary neuron__|
Notch OFF hemilineage neuron                |
 |__Notch OFF hemilineage secondary neuron__|
                                            columnar neuron T1  49 rec.
Spanning Tree View Settings
Parents/Children
View Depth
Show hierarchy levels: for parents, for children
hide Relationships
Is a optic lobe intrinsic columnar neuron
Notch OFF hemilineage secondary neuron
Develops from immature columnar neuron T1
Part of
hide Synonyms & Secondary IDs
Synonyms
Secondary IDs
hide External Crossreferences & Linkouts
FlyBrain_NDB:10115
VFB:FBbt_00003727