For the uninitiated, milt refers to the seminal fluid of fish, mollusks and other water-dwellers. If the concept of eating fish sperm seems a little strange, it's worth noting that milt is a delicacy enjoyed the world over. In Japan, it's called shirako (literally, “white children”) and is served fried, on top of sushi or as a garnish for chawanmushi, a classic egg custard dish. Tuna milt, on the other hand, is used in pasta on the Italian island of Sicily. Those living in Romania enjoy eating fried milt from freshwater fish.
For their study, the researchers investigated the effects of salmon milt extract on object recognition and object learning memory using healthy murine models. Object recognition is a cognitive function that involves recognition memory -- that is, the ability to identify events, objects or people previously encountered. In an object recognition test, a mouse is initially presented with two similar objects. One of the objects is replaced during the next session, and the amount of time the mouse takes to explore the new object is taken into account.
Object location memory, on the other hand, involves the use of spatial memory and the ability to discriminate between different objects. Object location memory tasks are often used to assess animal models of central nervous system disorders. For this task, a mouse is presented with four objects during the first session. Two items are switched before the second session, and the amount of time the mouse takes sniffing the objects is measured.
In the present study, healthy mice were first put on a diet that includes salmon milt before being subjected to behavioral tasks. The team noted that the mice devoted more time to exploring novel and moved objects than familiar and unmoved objects in the object recognition and object location memory tests. Mice fed a diet containing nucleic acid fractions from salmon milt also behaved in the same manner.
“This suggests that the nucleic acids may be a functional component contributing to the effects of [salmon milt] on brain function,” the researchers wrote in their report.
The researchers also noted that salmon milt improved markers for brain parenchyma, which includes all of the brain's functional tissues. Additionally, salmon milt increased the concentrations of cytosine, cytidine and deoxycytidine – nucleosides linked to DNA and RNA functions – in the hippocampus.
“Dietary intake of this easily ingestible food might enhance brain function in healthy individuals,” the team concluded. (Related: Salmon - A superfood that fills in the gaps.)
If milt isn't your cup of tea, there are other foods that you can eat to keep your brain healthy, and even improve concentration and memory. (h/t to Healthline.com)
Learn more about how to keep your brain healthy at Brain.news.