Tuneable reflexes

how hawkmoths position their antennae based on context

Insect antennae are marvelous sensory organs; insects use them to sense wind, smell food sources and mates, listen to mate wing-beat frequencies, detect minute vibrations required to stabilize flight and to sense temperature and humidity. Because the antennae sense so many different things, it is important to position them precisely in order to get the right information at the right time.

Insects have been shown to position their antennae differently based on the behavior they are performing. This act of positioning the antennae based on the behavioral context probably helps them acquire the necessary information for the current behavior.

How do insects dynamically position their antennae? This is the question we pursued in this project (also the focus of my PhD thesis).

Specifically, we focused on how hawkmoths dynamically change the position of their antennae based on airflow received by the antennae (frontal airflow). We investigated two aspects of the mechanisms underlying this behavior:

  1. The computational architecture that enables dynamic positioning of the antennae.
  2. The computation of preferred position (or set-point) based on the current airflow (sensory context).

Computational architecture

Turns out, tuneable feedback loops form the core architecture of neural circuits that control dynamic positioning in antennae. We found this by performing behavioral experiments and analyzing the data using control theoretic and neural circuit models. The details of our study can be found in the below publication:

  1. Nat. Commun.
    Tuneable reflexes control antennal positioning in flying hawkmoths
    Natesan, Dinesh, Saxena, Nitesh, Ekeberg, Örjan, and Sane, Sanjay P
    Nature communications 2019

Computation of preferred position

This is our current pursuit. Using behavioral and electrophysiological experiments, we look at how the preferred antennal position or the antennal set-point is computed based on airflow.

This will be updated soon based on the progress of the project. Can’t wait? Preliminary results are in my thesis (Chapter 3, link below). Still curious? Feel free to contact me to know more about this.

  1. PhD Thesis
    Neuromechanical basis of airflow-dependent antennal positioning in hawkmoths
    Natesan, Dinesh

Here is a popular science-y set of tweets highlighting the interesting aspects of the tuneable reflexes paper (Note that it is a set of tweets - check it out by clicking on the twitter icon on the right-top corner)