# Hatchlings and Neonate Turtle Gonads Have Spatially Restricted Neural Processes

## TL;DR

Neonate turtles do not feel pain during gonadal biopsy due to limited neural connections in their developing gonads.

## Contribution

The study provides morphological and molecular evidence explaining the absence of pain perception in neonate turtles during biopsy.

## Key findings

- Neonate turtles lack neural processes reaching the cortical layer of the gonads.
- Standard behavioral indicators of pain were absent in turtles undergoing biopsy.
- Young turtles have limited neural connections to the gonadal medulla compared to mice.

## Abstract

Morphological and molecular evidence explains the lack of nociception (“pain”) associated with very small, laparoscopic gonadal biopsy in neonate turtles. This safe procedure serves to verify neonate sex of late-maturing species, such as sea turtles. Ethical concerns about the potential for biopsy pain, inferred from mammals, limited access to sex verification biopsy for decades. Yet, standard behavioral evidence of pain during biopsy (e.g., escape attempts, biting, guarding behavior after biopsy, inappetence) were negative. Morphological and molecular evidence early in ontogeny, shows that, unlike mice, young turtles have limited neural processes to the gonadal medulla and none reach the cortical layer.