Simple minds – competition of parallel neural filters in behaviour selection of Drosophila

Introduction

How we and other animals ‘make up our minds’ is an everlasting question that has occupied philosophers and scientists for centuries. Sensory-evoked activity patterns, memory engrams, and internally generated brain activity conveying the animal’s internal state are meant to integrate to promote appropriate behaviour.

Research Gaps

Still, direct evidence for how integration works on the network, the neurophysiological, and the molecular level remains limited.

Study Focus

Exemplifying internal needs with tiredness and hunger, and focusing on the numerically simple brain of Drosophila, we here test a parallel filter hypothesis to explain how sensory and internal states are integrated across the relevant centres of the fly brain.

Hypothesis

We posit that parallel neural filters will have changed permeability for sensory stimuli and to compete. For example, if hungry, neural networks promoting food approach behaviour will change their permeability for sensory cues relative to those promoting sleep.

Methodology

Our approach will visualise neural activity while recording online fly behaviour related to hunger, sleep, and experience on a treadmill. It will tackle the physiological basis shaping filters, including:

1. Oscillatory cell and network activities
2. Synaptic gating
3. Whole brain activity recording

We capitalise on our expertise in functional imaging and previous discoveries of hunger and sleep gates, as well as their synaptic and network substrates.

Molecular Investigation

We will investigate and interfere with key molecular factors underlying filtering to directly challenge network integration and behavioural outcomes.

Remote Control Experiment

Finally, we will remote control competing parallel filters to test whether sensory permeability can switch the animal’s state between an ego- and an allocentric-like world view. We will also explore whether depression-like states related to learnt helplessness will favour an egocentric filter setting.

Conclusion

Understanding neural filter properties should allow further insights into the physiological basis of depressed states.