Locomotor control by the central complex in Drosophila—An analysis of the tay bridge mutant

Abstract

Several aspects of locomotor control have been ascribed to the central complex of the insect brain; however, the role of distinct substructures of this complex is not well known. The tay bridge1 (tay1) mutant of Drosophila melanogaster was originally isolated on the basis of reduced walking speed and activity. In addition, tay1 is defective in the compensation of rotatory stimuli during walking and histologically, tay1 causes a mid-sagittal constriction of the protocerebral bridge, a constituent of the central complex. Cloning of the tay gene revealed that it encodes a novel protein with no significant homology to any known protein. To associate the behavioral phenotypes with the anatomical defect in the protocerebral bridge, we used different driver lines to express the tay cDNA in various neuronal subpopulations of the central brain in tay1-mutant flies. These experiments showed an association of the aberrant walking speed and activity with the structural defect in the protocerebral bridge. In contrast, the compensation of rotatory stimuli during walking was rescued without a restoration of the protocerebral bridge. The results of our differential rescue approach are supported by neuronal silencing experiments using conditional tetanus toxin expression in the same subset of neurons. These findings show for the first time that the walking speed and activity is controlled by different substructures of the central brain than the compensatory locomotion for rotatory stimuli.

The role of the cerebral ganglia in the venom-induced behavioral manipulation of cockroaches stung by the parasitoid jewel wasp

“…This clearly indicates that the CX is permissive for the initiation of spontaneous walking. Our result is consistent with work carried out on Drosophila melanogaster, which shows that flies with genetically manipulated neurons or structural mutations of the CX demonstrate shorter activity duration, lower walking speed, decreased levels of locomotory activity and changes in walking time intervals (Strauss et al, 1992;Strauss and Heisenberg, 1993;Martin et al, 1999;Strauss, 2002;Poeck et al, 2008;Kahsai et al, 2010;Pfeiffer and Homberg, 2014). It is also in good agreement with experiments showing that current injection into the CX can elicit walking in crickets (Huber, 1960) and cockroaches (Bender et al, 2010).…”

Genome-wide association and genetic functional studies identify autism susceptibility candidate 2 gene ( AUTS2 ) in the regulation of alcohol consumption

“…In contrast, down-regulation of AUTS2 homolog tay in Drosophila results in reduced sensitivity to the effects of alcohol, pointing to AUTS2-mediated regulation of the level of response to alcohol. Although the percent homology shared by mammalian AUTS2 and Drosophila tay proteins is low, a neurological role for Drosophila tay has been described (24). A low level of response to alcohol has been identified as a risk factor for alcohol dependence in both human and animal studies (25,26).…”

Inter-leg coordination in the control of walking speed inDrosophila

“…For the strains wt CS and wt Berlin , the reported average walking speeds in the literature range from 2.2 and 2-3mms -1 (Serway et al, 2009) to 15 and 21mms -1 (Poeck et al, 2008;Strauss and Heisenberg, 1993), respectively. Average walking speed for w 1118 was reported to be approximately 2mms -1 and for w 1118 , Tbh nM18 it was 4mms -1 (Scholz, 2005).…”

“…It should be noted, though, that we used a different behavioral protocol from that in previous studies. Some of these used Buridan's paradigm (Bülthoff et al, 1982;Götz, 1980) to elicit straight walks on level ground (Poeck et al, 2008;Serway et al, 2009;Strauss and Heisenberg, 1990;Strauss and Heisenberg, 1993), while others studied walking in Drosophila under ambient light conditions without the presentation of visual cues (Scholz, 2005;Wolf et al, 2002).…”