While its exact function and importance in the physiology of the brain are still not entirely clear, it has been demonstrated in humans that surgical transection—the cutting of the fornix along its body—can cause memory loss.

This means that damage to the fornix can cause difficulty in recalling long-term information such as details of past events, but it has little effect on the ability to recognize objects or familiar situations.

The lower edge of the septum pellucidum (the membrane that separates the lateral ventricles) is attached to the upper face of the fornix body.

Diverging from one another, each curves around the posterior end of the thalamus, and passes downward and forward into the temporal horn of lateral ventricle.

Fornix transection in rodents impairs performance on tasks that require the encoding and retrieval of spatiotemporal context and, therefore, serves as a proxy for human episodic memory.

For instance, fornix transection consistently leads to robust impairments in learning new routes and spatial locations.

[6] The fornix is the conduit by which the neurotransmitter acetylcholine – which is crucial for memory encoding – is sent from the medial septum/Diagonal band of Broca to the hippocampus.

In addition, the fornix transmits mnemonic information from the hippocampus to deep brain structures, which potentially allows us to use stored memories to guide us to rewarding people, places, and sources of sustenance.