Recent research suggests several properties of cannabinoids could help repair perinatal brain injury.
A perinatal brain injury means one that occurs during the birthing process. These are often the result of a fetus lacking oxygen in the uterus due to an external accident that dramatically blocks oxygen flow, such as the placenta prematurely separating from the uterine wall. However, reduced blood flow in newborns or stroke-induced blood clots can also cause perinatal brain damage.
The areas of the brain most commonly damaged are the basal ganglia and the parasagittal region of the cerebral cortex.
Brain cell death and brain lesions can result in long-term functional impairment. Perinatal brain injuries can have a wide range of effects depending on the location and severity. Typical impairments can include behavioral, cognitive, and physical. Neonatal hypoxic-ischemic encephalopathy, for example, is the most common brain injury for newborns. Sats says that between one and six newborns out of a thousand will suffer from it. Yet, despite the high rates of perinatal brain injury, treatment options are limited, so new therapies are desperately needed.
Cannabinoids May Help Repair Perinatal Brain Injuries
Cannabis is a potential novel treatment for perinatal brain injury. Its active compounds are known as cannabinoids, with the main two being tetrahydrocannabinol (THC) and cannabidiol (CBD). These cannabinoids create a range of cellular responses by binding to receptors. THC initiates its cellular responses by binding to cannabinoid receptors, namely the G-protein coupled receptors CB1 and CB2. CBD, on the otherhand, binds to non-cannabinoid receptors and modulates receptor pathways.
Research suggests that these cellular responses may repair damage and offer neuroprotection for newborns suffering perinatal brain injury.
Cannabis Reduces Damage Caused by Glutamate Exotoxicity
One of the typical indications of perinatal brain toxicity is the presence of glutamate excitotoxicity. Ischemia results in reduced blood flow with reduced oxygen levels being one of the causes of perinatal brain injury. Glutamate plays a key role in ischemia. Glutamate is an excitatory neurotransmitter and is active when there is lack of blood flow, resulting in continued damage after the initial injury.
Evidence suggests that cannabinoids protect the brain from excitotoxic injury, with one study even finding that the endocannabinoid system may provide on-demand protection for neurons from acute excitotoxicity. Another study suggests that the activation of CB1 receptors by cannabinoids, such as THC, inhibits glutamatergic transmission. This reduces glutamate levels and protects the brain from the risks of glutamate excitotoxicity.
Cannabis May Reduce Neuroinflammation
The cell damage seen in patients with perinatal brain injury is largely thanks to neuroinflammatory reactions. Inflammation of the brain is another indication of perinatal brain injury and it seems that cannabis may also offer some protection from it.
Cannabinoids were able to modulate the immune reactions in the brain that lead to inflammation and cell damage. T-cells, microglia, cytokines play key roles in starting immune responses, such as inflammation, and the activation of cannabinoid receptors have been shown to modulate the levels and expressions of these immune factors. THC in particular may have strong anti-inflammatory properties thanks to its effects on microglia. A type of glial cell, microglia play the role of macrophages in the brain and are a primary neuroimmune defense. Research tells us that the activation of cannabinoid receptors by THC may be able to control the function of microglia and may possibly act as a therapeutic tool against neuroinflammation.
CBD may also play a role in cannabis’ ability to reduce neuroinflammation thanks to its action on glycine receptors. One rodent study found that CBD was able to enhance the expression of GlyR. This is a glycine receptor that mediates the glycinergic cannabinoid-induced suppression of inflammation in mouse models for brain inflammation.
Cannabis May Promote Growth of New Brain Cells
Any treatment that could increase neural cell proliferation and increase cell survival would significantly improve patient outcomes.
Cannabis may have a positive effect on neural cell proliferation through the receptor CB2. The CB2 receptor exists in certain areas of the brain and has shown to be expressed in neural progenitors from the late embryonic stages. One study (rodent) showed that activation of the CB2 receptor resulted in the promotion of neural progenitors cell proliferation and generation. Cells low in CB2 receptors did not see these results. By possibly restoring neural cell levels and enhancing brain function in this way, cannabis could indeed help. The activation of CB2 through cannabinoids could be able to treat perinatal brain injury. The cannabinoids would achieve this by enhancing the brain’s response to perinatal brain injury.
In short, medical cannabis may make the future brighter for those suffering from perinatal brain injury. Further research is necessary before any trials on human babies.