Oct 08, 2025
- Mario Alberto Bautista-Carro1
- 1Cinvestav
External link: https://doi.org/10.1371/journal.pone.0339028
Protocol Citation: Mario Alberto Bautista-Carro 2025. Olfactory bulbectomy. protocols.io https://dx.doi.org/10.17504/protocols.io.81wgbwqjngpk/v1
Manuscript citation:
Bautista-Carro MA, Sánchez-Teoyotl P, Juárez-Serrano D, Iannitti T, Díaz A, Flores G, Morales-Medina JC (2026) Olfactory bulbectomy induces neurobiological alterations in the prefrontal cortex and hyperlocomotion in male rats. PLOS One 21(1). doi: 10.1371/journal.pone.0339028
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: October 07, 2025
Last Modified: October 08, 2025
Protocol Integer ID: 229209
Keywords: Depression model, Depression-like behavior, Anxiety-like behavior, olfactory bulbectomy bilateral olfactory bulbectomy, bulbectomy bilateral olfactory bulbectomy, surgical removal of both olfactory bulb, olfactory bulb, obx in rat, olfactory, obx, surgical removal, studying major depression, major depression
Abstract
Bilateral olfactory bulbectomy (OBX) involves the surgical removal of both olfactory bulbs. It is a classic animal model for studying major depression. Below we describe the protocol for performing an OBX in rats.
Guidelines
Rats should be randomly assigned to one of two surgical groups, sham or OBX injury, and receive post-surgical care. Do everything possible to reduce animal suffering. Before or during the experiment, animals showing signs of suffering must be examined immediately by a veterinarian and, if necessary, euthanized.
Materials
Ketamine
Xylazine
Sterile saline
Benzalkonium chloride
Iodopovidone
Microdrill
Cannula connected to a distilled water pump
Hemostatic sponge
Hartmann's solution
Surgical instruments
Syringes
Cotton balls and gauze
Troubleshooting
Before start
Verify availability of equipment, anesthesia, and necessary supplies.
Anesthetize the rats via intraperitoneal injection of a ketamine/xylazine cocktail (0.75 ml ketamine + 0.25 ml xylazine + 5 ml sterile saline), at a dose of 0.125 ml per 20 g of body weight.
Once anesthetized, shave the head and perform asepsis using benzalkonium chloride and iodopovidone.
Make a 1 cm midline incision on the skull from the forehead to the dorsum of the nose. Uncover the aponeurosis and periosteum to reach the bone.
Drill two holes (2 mm diameter) with a microdrill, located 8 mm anterior to the bregma and 1 mm from the midline of the frontal bone.
Aspirate the olfactory bulbs using a sterile cannula connected to a distilled water pump, taking care not to cause damage to the prefrontal cortex. For the sham group, perform the same surgery except that the olfactory bulbs are not removed.
To prevent blood loss, fill the holes with hemostatic sponge (Spongostan, Ethicon, Inc. USA), suture continuously and cover with iodopovidone.
Post-surgery, administer 4 ml of Hartmann's solution (PiSA, México) via subcutaneous injection. House the rats in pairs (Sham/OBX) in their respective cages to recover for four weeks.
At the end of the recovery period and behavioral testing, verify that the removal of the olfactory bulbs is complete and that there is no damage to the prefrontal cortex.
Protocol references
Galindo-Paredes, G., Flores, G., & Morales-Medina, J. C. (2023). Olfactory bulbectomy induces nociceptive alterations associated with gliosis in male rats. IBRO neuroscience reports, 14, 494–506. https://doi.org/10.1016/j.ibneur.2023.05.006
Morales-Medina, J. C., Dumont, Y., Benoit, C. E., Bastianetto, S., Flores, G., Fournier, A., & Quirion, R. (2012). Role of neuropeptide Y Y₁ and Y₂ receptors on behavioral despair in a rat model of depression with co-morbid anxiety. Neuropharmacology, 62(1), 200–208. https://doi.org/10.1016/j.neuropharm.2011.06.030