Connectivity of three neuron types in the fan-shaped body of the sweat bee: potential substrate for vector memory
(2025) BIOM02 20242Degree Projects in Biology
- Abstract
- Path integration is a navigational strategy that allows animals to return home in a straight line after an outbound journey, by integrating the distance and direction traveled. With their accessible brains, insects are the perfect model organisms to study this target-directed behavior at the neural level. The Central Complex (CX) is a group of neural structures (neuropils) in the insect brain suited to host most computations required for path integration, such as internally representing the direction the animal is facing and generating steering commands if this direction does not match the goal direction. It is still unknown however how vector memory is encoded, which is necessary to efficiently lead the animal back to the starting point... (More)
- Path integration is a navigational strategy that allows animals to return home in a straight line after an outbound journey, by integrating the distance and direction traveled. With their accessible brains, insects are the perfect model organisms to study this target-directed behavior at the neural level. The Central Complex (CX) is a group of neural structures (neuropils) in the insect brain suited to host most computations required for path integration, such as internally representing the direction the animal is facing and generating steering commands if this direction does not match the goal direction. It is still unknown however how vector memory is encoded, which is necessary to efficiently lead the animal back to the starting point in a straight line. There is behavioral evidence of path integration in many insect species. The focus of this study is the tropical sweat bee Megalopta genalis. Hymenopterans have a region in one of the neuropils of the CX that other insects orders do not have, the cap region of the noduli (NOc). Three cell types project to the NOc, where their connections have been already unraveled: PFNc, PFNmc and FBt-NOc neurons. In this connectomic study, I investigated the connectivity of these neurons in another neuropil that they all project to, the Fan-shaped Body (FB). I first looked at their overall synaptic partners, then at the differences between two subtypes of FBt-NOc neurons. Finally, I looked at the interactions only between these three cell types. The findings suggest that there are variations in connectivity within the investigated cell types in the FB. These cells form recurrent loops with each other between the FB and the NOc, a relationship that can promote sustained neural activity. (Less)
- Popular Abstract
- Sweat bee and navigation: description of Hymenopteran-specific neurons in the Central Complex
Insects navigate in sophisticated ways, from migrations across continents to flexible shortcuts between pollination sites. Their brains are highly accessible for the study of behavior at the level of brain regions, circuits and single neurons. Moreover, the structure of the insect brain is evolutionary conserved, a key aspect for comparative studies across species that have different adaptations and sensory modalities.
This study focuses on the brain of the Megalopta genalis, a tropical, solitary and nocturnal sweat bee. A common and efficient navigational strategy used by central place foragers like bees is path integration, a process they... (More) - Sweat bee and navigation: description of Hymenopteran-specific neurons in the Central Complex
Insects navigate in sophisticated ways, from migrations across continents to flexible shortcuts between pollination sites. Their brains are highly accessible for the study of behavior at the level of brain regions, circuits and single neurons. Moreover, the structure of the insect brain is evolutionary conserved, a key aspect for comparative studies across species that have different adaptations and sensory modalities.
This study focuses on the brain of the Megalopta genalis, a tropical, solitary and nocturnal sweat bee. A common and efficient navigational strategy used by central place foragers like bees is path integration, a process they rely on a daily basis to return to the hive after foraging.
This strategy allows the individual to keep track of the directional changes and distance traveled during the journey and get back home in the shortest path possible. Different studies suggest that a specific region of the insect brain is likely accountable for coordinating this strategy.
This region is called the Central Complex (CX) and is a fundamental interface between sensory input and motor commands. In bees, visual and proprioceptive cues are the primary sources of sensory information that the CX could use to generate the way back to the hive. The neurons that move such information in this region are divided into different classes and types depending on the areas of the CX they project to.
These cell types, as well as the general structure of the CX, are highly conserved across insects.
However, there is an additional area in the CX of Hymenopterans (bees, ants and wasps) that has not been observed in other orders. This area, called the cap region of the noduli (NOc), is innervated by three types of neurons. The aim of this thesis is to look at their morphology and connections. The results are preliminary evidence to understand how these three cell types move information across the CX and possibly take part in the process that generates the home vector. More specifically, this study reveals that these neurons can create recurrent loops with each other, which can promote signal stability. Additional insights are given by the connections that these three cell types have with other neurons. Their synaptic partners are known to be involved in circuits that allow the animal to keep track of its travel direction. Together, these findings offer a first glimpse into Hymenopteran-specific neurons in the CX. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9215080
- author
- Monteleone, Arianna
- supervisor
- organization
- course
- BIOM02 20242
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9215080
- date added to LUP
- 2025-11-07 12:22:22
- date last changed
- 2025-11-07 12:22:22
@misc{9215080,
abstract = {{Path integration is a navigational strategy that allows animals to return home in a straight line after an outbound journey, by integrating the distance and direction traveled. With their accessible brains, insects are the perfect model organisms to study this target-directed behavior at the neural level. The Central Complex (CX) is a group of neural structures (neuropils) in the insect brain suited to host most computations required for path integration, such as internally representing the direction the animal is facing and generating steering commands if this direction does not match the goal direction. It is still unknown however how vector memory is encoded, which is necessary to efficiently lead the animal back to the starting point in a straight line. There is behavioral evidence of path integration in many insect species. The focus of this study is the tropical sweat bee Megalopta genalis. Hymenopterans have a region in one of the neuropils of the CX that other insects orders do not have, the cap region of the noduli (NOc). Three cell types project to the NOc, where their connections have been already unraveled: PFNc, PFNmc and FBt-NOc neurons. In this connectomic study, I investigated the connectivity of these neurons in another neuropil that they all project to, the Fan-shaped Body (FB). I first looked at their overall synaptic partners, then at the differences between two subtypes of FBt-NOc neurons. Finally, I looked at the interactions only between these three cell types. The findings suggest that there are variations in connectivity within the investigated cell types in the FB. These cells form recurrent loops with each other between the FB and the NOc, a relationship that can promote sustained neural activity.}},
author = {{Monteleone, Arianna}},
language = {{eng}},
note = {{Student Paper}},
title = {{Connectivity of three neuron types in the fan-shaped body of the sweat bee: potential substrate for vector memory}},
year = {{2025}},
}