Anatomical and ultrastructural analysis of the posterior optic tubercle in the locust Schistocerca gregaria

Held, Martina; Le, Kim; Pegel, Uta; Dersch, Florian; Beetz, M. Jerome; Pfeiffer, Keram; Homberg, Uwe

doi:10.1016/j.asd.2020.100971

Cited by 4 publications

(4 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dendrites of locust TB neurons in the POTU receive significant input from the accessory medulla, directly from the circadian clock via pigment-dispersing factor (PDF) neurons (Held et al 2020 ). The implementation of time compensation in navigational behaviors (the ability to maintain a global spatial reference frame by adjusting for the apparent motion of celestial cues by integrating their movement over time) requires input from an internal clock, and the POTU pathway is postulated as its neural substrate.…”

Section: Resultsmentioning

confidence: 99%

Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex

et al. 2023

View full text Add to dashboard Cite

The representation and integration of internal and external cues is crucial for any organism to execute appropriate behaviors. In insects, a highly conserved region of the brain, the central complex (CX), functions in the representation of spatial information and behavioral states, as well as the transformation of this information into desired navigational commands. How does this relatively invariant structure enable the incorporation of information from the diversity of anatomical, behavioral, and ecological niches occupied by insects? Here, we examine the input channels to the CX in the context of their development and evolution. Insect brains develop from ~ 100 neuroblasts per hemisphere that divide systematically to form “lineages” of sister neurons, that project to their target neuropils along anatomically characteristic tracts. Overlaying this developmental tract information onto the recently generated Drosophila “hemibrain” connectome and integrating this information with the anatomical and physiological recording of neurons in other species, we observe neuropil and lineage-specific innervation, connectivity, and activity profiles in CX input channels. We posit that the proliferative potential of neuroblasts and the lineage-based architecture of information channels enable the modification of neural networks across existing, novel, and deprecated modalities in a species-specific manner, thus forming the substrate for the evolution and diversification of insect navigational circuits.

show abstract

Section: Resultsmentioning

confidence: 99%

Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex

et al. 2023

View full text Add to dashboard Cite

show abstract

“…A similar connection has been shown in the desert locust, where the POTU has been investigated in some detail (Homberg & Würden, 1997). An ultrastructural study demonstrated that PDF‐ir is found in fibers that have output synapses in the POTU (Held et al., 2020), suggesting that the POTU in locusts receives direct input from the accessory medulla. As in the honeybee, the locust POTU is therefore assumed to play a role in time‐compensation of the sky‐compass.…”

Section: Discussionmentioning

confidence: 99%

A three‐dimensional atlas of the honeybee central complex, associated neuropils and peptidergic layers of the central body

Hensgen

Tschirner

Beetz

et al. 2022

J of Comparative Neurology

Self Cite

View full text Add to dashboard Cite

The central complex (CX) in the brain of insects is a highly conserved group of midlinespanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution threedimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.

show abstract

“…In many insects, notably Drosophila and the cockroach Rhyparobia maderae , the master circadian clock controlling locomotor activity rhythms is closely associated with the accessory medulla, a small neuropil at the anterior edge of the medulla (Helfrich-Förster et al 1998 ; Helfrich-Förster 2005 ). Although a circadian pacemaker function for the accessory medulla of the locust still awaits experimental evidence, a prominent fiber fascicle specifically connects this neuropil to the posterior optic tubercle (Homberg and Würden 1997 ; el Jundi and Homberg 2010 ), where it exhibits presynaptic terminals (Held et al 2020 ), offering the attractive hypothesis that time compensation may act through this pathway to shift the internal goal relative to the sky compass in the CX.…”

Section: Feedbacks and Activity Shifts In The Sky Compassmentioning

confidence: 99%

The sky compass network in the brain of the desert locust

et al. 2022

Self Cite

View full text Add to dashboard Cite

Many arthropods and vertebrates use celestial signals such as the position of the sun during the day or stars at night as compass cues for spatial orientation. The neural network underlying sky compass coding in the brain has been studied in great detail in the desert locust Schistocerca gregaria. These insects perform long-range migrations in Northern Africa and the Middle East following seasonal changes in rainfall. Highly specialized photoreceptors in a dorsal rim area of their compound eyes are sensitive to the polarization of the sky, generated by scattered sunlight. These signals are combined with direct information on the sun position in the optic lobe and anterior optic tubercle and converge from both eyes in a midline crossing brain structure, the central complex. Here, head direction coding is achieved by a compass-like arrangement of columns signaling solar azimuth through a 360° range of space by combining direct brightness cues from the sun with polarization cues matching the polarization pattern of the sky. Other directional cues derived from wind direction and internal self-rotation input are likely integrated. Signals are transmitted as coherent steering commands to descending neurons for directional control of locomotion and flight.

show abstract

Anatomical and ultrastructural analysis of the posterior optic tubercle in the locust Schistocerca gregaria

Cited by 4 publications

References 59 publications

Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex

Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex

A three‐dimensional atlas of the honeybee central complex, associated neuropils and peptidergic layers of the central body

The sky compass network in the brain of the desert locust

Contact Info

Product

Resources

About