Researchers from the U.S., Canada and China say a marijuana-like substance in the brain has both positive and negative implications for those suffering from seizures, resulting in less intense events, but potential memory loss.

Ivan Soltesz, Ph.D., a senior author and professor of neurosurgery at Stanford University, was among the members of a team exploring the effects of 2-arachidonoylglycerol (2-AG), which mirrors its plant-based counterpart.

The endocannabinoid is “a member of a family of short-lived signaling substances that are the brain’s internal versions of the psychoactive chemicals in marijuana,” explains an article posted by the Stanford University School of Medicine.

Investigators found that 2-AG “has the beneficial effect of damping down seizure intensity,” the school reports.

Explaining that epileptic seizures trigger the rapid synthesis and release of the substance, 2-AG also breaks down rapidly. This “trips off a cascade of biochemical reactions culminating in blood-vessel constriction in the brain and, in turn, the disorientation and amnesia that typically follow an epileptic seizure.”

Typically, a person experiencing an epileptic seizure may “need tens of minutes before becoming clearheaded again,” the school reports.

Appearing in Neuron, researchers suggest their findings could guide the development of drugs that help curb seizure strength and reduce after-effects. “We now demonstrate that the endocannabinoid 2-arachidonoylglycerol, not anandamide, is dynamically coupled to hippocampal neural activity with high spatiotemporal specificity,” the study states.

Epileptic seizures, the majority of which originate in the hippocampus, involve nerve cells in one part of the brain repeatedly firing together in synchrony before that hyperactivity possibly spreads to other areas. This can result in symptoms such as loss of consciousness and convulsions.

“The hippocampus plays an outsized role in short-term memory, learning and spatial orientation,” according to the study.

As such, researchers monitored split-second changes in levels of 2-AG in the hippocampus of mice during both normal activity and seizure-induced periods.

While smoking cannabis leaves the entire brain with relatively long-lasting THC, endocannabinoids target specific spots under precise circumstances and break down quickly, Soltesz explains.

This fast breakdown means existing biochemical methods are too slow to measure their levels in animals’ brains. But using a modified version of CB1 that emits a fluorescent glow allowed investigators to see changes correlating with endocannabinoid levels where binding was occurring.

The study showed several hundred times as much 2-AG was released when a mouse was having a seizure compared to when it was taking part in normal activity, such as running in place.

But because the substance is almost immediately converted to arachidonic acid, a building block for inflammatory compounds, this led to constriction of tiny blood vessels in the brain and cut off oxygen supply to parts of the brain.

Soltesz reports that oxygen deprivation is known to produce the cognitive deficits, including disorientation and memory loss, that sometimes follow seizures.

“A drug that blocks 2-AG’s conversion to arachidonic acid would kill two birds with one stone,” he says. “It would increase 2-AG’s concentration, diminishing seizure severity, and decrease arachidonic acid levels, cutting off the production of blood-vessel-constricting prostaglandins.”

According to the Epilepsy Foundation, early evidence from laboratory studies, anecdotal reports and small clinical studies over a number of years suggest that CBD could potentially help control seizures. A number of studies published in recent years have shown “the benefit of specific plant-based CBD product in treating specific groups of people with epilepsy who have not responded to traditional therapies,” it adds.