ZeTox – Toxicology Services


icon-neuro-tox NeuroTox – Neurotoxicity Service

Exposure to some drugs might alter the normal activity of the nervous system, even promoting irreversible damage to nervous tissue. Neurotoxicity is remarkably common and among the most frequent reasons for drug attrition. NeuroTox take advantage of the high similarity between zebrafish and human nervous system structure and function.

Figure 1. Conserved brain structures between zebrafish and humans.


Assessment of a wide myriad of behavioral phenotypes such as feeding, seizures, involuntary movement, sleeping, and addiction.

Customizable experimental design.

Evaluation of potential neurotoxicity protective candidates.

Simultaneous assessment of cardiotoxicity and hepatotoxicity through the service ZeGlobalTox.

Method description

Transgenic zebrafish larvae expressing green fluorescent protein (GFP) in a neuronal transgenic reporter are incubated with the No Observable Effect Concentration (NOEC) of the molecule of interest from 96 hpf to 120 hpf. Locomotor activity is measured during the incubation period (to normalize circadian rhythm impact) through a video with DanioVision™ system (Noldus IT). Alternating light and dark will be run during the video. Alterations in behaviour are evaluated after applying different stimuli and subsequently associated with specific drug-induced neuronal impact. Optionally, larvae can be then fixed and neuronal clusters observed to determine changes in neuronal number.


Determination of behavioural phenotypes at 120 hpf:

  • Locomotor activity
  • Thigmotaxis
  • Altered response to light stimuli
  • Habituation
  • Seizures
  • Neuronal survival
Figure 2. General motor activity evaluation. Light/Dark locomotion pattern of zebrafish larvae in response to a negative control, to a neurotoxic agent (positive control) and a study compound that doesn’t produce neurotoxic effect on basal locomotor activity.

Figure 3. Convulsive behavior assessment. Maximum velocity and the number of angle turns of the larvae treated with vehicle (negative control), convulsive compound (positive control), and a study molecule that does not produce seizures in response to light flash.


  1. Cornet C, Calzolari S, Miñana-Prieto R, Dyballa S, van Doornmalen E, Rutjes H, Savy T, D'Amico D, Terriente J. ZeGlobalTox: An Innovative Approach to Address Organ Drug Toxicity Using Zebrafish. Int J Mol Sci. 2017 Apr 19;18(4):864.
  2. Kokel D, Bryan J, Laggner C, White R, Cheung CY, Mateus R, Healey D, Kim S, Werdich AA, Haggarty SJ, Macrae CA, Shoichet B, Peterson RT. Rapid behavior-based identification of neuroactive small molecules in the zebrafish. Nat Chem Biol. 2010 Mar;6(3):231-237.