Name: Andreea-Diana Moisa

Student number: 100705607

Name of TA: Angela Paric

Thesis statement: Following ischemic stroke, activating cannabinoid receptor types 1 and 2

(CB1 and CB2, respectively) using endogenous and synthetic agonists appears to have

neuroprotective effects.

Final paper:

Abstract:

Ischemic stroke is a result of a blockage of the blood flow to the brain, leading to cells

lacking the necessary oxygen and glucose for survival. The reduced blood flow triggers a cascade of

cellular and molecular events leading to a toxic increase in the intracellular levels of calcium.

Cannabinoids have shown to reduce or stop brain damage by interfering with this cascade through

activation of the CB1 and CB2 receptors. The following review article describes these mechanisms and

discusses various evidence for the therapeutic potential of cannabinoids in ischemic stroke and other

similar neurodegenerative disorders.

Introduction:

The continuous delivery of oxygen and glucose to the brain through blood flow is necessary for

brain function, and interruption of the cerebral blood supply leads to ischemic stroke. Hypoxia-ischemia

refers to a condition where blood flow to cells and organs is not sufficient to maintain their

normal function and results in a lower-than-normal concentration of oxygen in arterial blood

(Iadecola & Anrather, 2011). Immunity and inflammation are the main components of the

pathology of stroke, which is second to cardiac ischemia as a cause of death worldwide (Iadecola

& Anrather, 2011). Although inflammation was thought to be only a reaction to tissue damage, it

has now been recognized as a contributor to cerebrovascular diseases, especially stroke caused

by arterial occlusion or ischemic stroke (Iadecola & Anrather, 2011).

From ischemia to infarction: the ischemic cascade:

Ischemic damage results from a cascade of cellular and molecular events triggered by sudden

lack of blood flow (Iadecola & Anrather, 2011). Neurons are more vulnerable than glia or vascular

cells and become quickly dysfunctional or die when exposed to hypoxia-ischemia (Iadecola &

Anrather, 2011). In the most common type of stroke, caused by a blockage of the middle cerebral artery,

the damage is more rapid and severe in the center (ischemic core), where blood flow is lowest (Iadecola

& Anrather, 2011). At the periphery of the ischemic region (ischemic penumbra), neuronal damage

develops more slowly because blood flow arising from adjacent vascular territories keeps cerebral

perfusion above the threshold for immediate cell death (Iadecola & Anrather, 2011). In the ischemic

core, the major reason for cell death is that without oxygen and glucose, neurons cannot synthesize the

ATP needed to fuel the ionic pumps that maintain the ionic gradient across the membrane. Consequently,

massive Na+ and Ca2+ influx leads to swelling of the organelles, loss of membrane integrity and

dissolution of the cell (Iadecola & Anrather, 2011). In the ischemic penumbra, the flow is sufficient for

some energy production; neurons remain viable for a prolonged period of time, but the neurons are

stressed and vulnerable to pathogens (Iadecola & Anrather, 2011). Excessive extracellular

accumulation of glutamate causes neuronal damage in the ischemic penumbra. The resulting

overactivation of the NMDA glutamate receptors leads to cytoplasmic accumulation of Ca2+ which

activates Ca2+-dependent enzymes, including the proteases calpain and caspase, and enzymes producing

nitric oxide, free radicals and arachidonic acid metabolites (Iadecola & Anrather, 2011). These events

lead to necrosis or programmed cell death depending on the intensity of injury and the metabolic state of

the neurons (Iadecola & Anrather, 2011). Injured and dying cells have a key role in post-ischemic

inflammation because they release danger signals that activate the immune system (Iadecola &

Anrather, 2011).

Cannabinoids as possible therapeutic agents

Cannabinoids are a class of various chemical compounds that act on cannabinoid

receptors (Fernández-Ruiz et al., 2010). Some originate from the cannabis plant, some are

produced endogenously, and some are manufactured synthetically. They are promising

neuroprotective molecules, due to their ability to normalize glutamate homeostasis, reduce

excitotoxicity, inhibit calcium influx, and reduce the generation of reactive oxygen

intermediates, decreasing oxidative injury (Fernández-Ruiz et al., 2010). Cannabinoids are also

able to decrease inflammation by acting on glial processes that regulate neuronal survival, and to

restore blood supply by reducing vasocontriction produced by endothelium-derived factors

(Fernández-Ruiz et al., 2010).

The endocannabinoid system and the control of death/survival cell decision

The endocannabinoid system seems to also play a role in the cellular decision of

death/survival (Fernández-Ruiz et al., 2010). Cannabinoids have demonstrated apparently

opposite actions, neuroprotective and antiproliferative effects. A possible explanation is that

these effects occur in different cell states (e.g., healthy cells for the neuroprotective effect and

transformed cells for the antiproliferative action), and that they involve the activation of different

signaling mechanisms for the cannabinoid receptors (Fernández-Ruiz et al., 2010). The type of

intracellular signals involved in the action of cannabinoid receptors has been continuously

updated in the last years, and numerous studies have shown that the activation of these receptors

triggers various intracellular pathways that are different from the classic inhibition of adenylyl-

cyclase and cAMP production (Fernández-Ruiz et al., 2010). Other intracellular pathways

activated by CB1 and CB2 receptors include the activation of MAPKs (e.g., ERK, JNK and p38)

and the stimulation of PI3K–Akt signaling (Fernández-Ruiz et al., 2010). These two pathways

have been strongly related to cell survival, therefore it is likely that they are highly involved in

neuroprotective effects mediated by the activation of cannabinoid receptors (Fernández-Ruiz et

al., 2010). Lastly, certain cannabinoids are also able to bind and activate the nuclear receptors

PPARs. These receptors have been strongly linked to the control of inflammatory events, and

may explain the inflammatory/neuroprotective properties of cannabinoids (Fernández-Ruiz et al.,

2010).

Cannabinoids and neuroprotection: general aspects

During the last decade, a large volume of studies have shown significant evidence that

certain cannabinoid compounds may be neuroprotective against acute or chronic brain damage

(Fernández-Ruiz et al., 2010). These studies were all preclinical and demonstrated

neuroprotection by cannabinoids against the following experimental conditions that are prevalent

in accidental injuries: i) glutamate excitotoxicity; ii) ischemic stroke; iii) hypoxia; iv) head

trauma; and v) oxidative stress (Fernández-Ruiz et al., 2010). Cannabinoids reduced infarct size

and the associated edema, and produced a recovery of neurological deficits in rodent models

reproducing cerebral ischemia (Fernández-Ruiz et al., 2010). In addition, cannabinoids also

served as neuroprotective in several chronic neurodegenerative pathologies characterized by

excitotoxicity, energy failure, mitochondrial dysfunction, inflammation or oxidative stress, such

as AD, PD, HD, ALS, or MS (Fernández-Ruiz et al., 2010).

Cannabinoids and calcium influx

Hyperactivation of glutamate receptors following hypoxic-ischemia leads to an increase

in intracellular calcium levels. The problem with extremely high intracellular levels of calcium is

the activation numerous destructive pathways (e.g., calpains, caspases and other proteases,

protein kinases, lipases, endonucleases, nitric oxide synthase, reactive oxygen species and

others) that threaten the cell. Cannabinoids are able to reduce calcium entry into the cell by

closing these voltage-sensitive ion channels (Fernández-Ruiz et al., 2010). This has been

demonstrated using different plant-derived, synthetic or endogenous cannabinoids in conditions

of high calcium levels produced by different neurotoxic stimuli (e.g., NMDA and other

excitotoxins). Most of these calcium-lowering effects were prevented by rimonabant, an inverse

agonist of the CB1 receptor, suggesting that they are mediated by the activation of CB1

receptors. However, CB1 receptors are located postsynaptically in neurons containing NMDA

glutamate receptors, and the receptors involved in the inhibition of glutamate release are

presynaptic (Fernández-Ruiz et al., 2010).

Cannabinoids and glutamate homeostasis

The inhibition of glutamate release to normalize glutamate homeostasis is probably the key event

underlying the neuroprotective effects of cannabinoid agonists (Fernández-Ruiz et al., 2010).

This has been demonstrated using cultured neurons obtained from various brain regions and

subjected to excitotoxic conditions. This effect is likely to be mediated by the activation of CB1

receptors that are located presynaptically in glutamatergic terminals, because this effect of

cannabinoid agonists is reversed by selective blockade of CB1 receptors (Fernández-Ruiz et al.,

2010). The fact that neuroprotection by cannabinoids in conditions of excitotoxicity is

preferentially CB1 receptor-mediated was demonstrated in studies conducted with CB1-receptor-

deficient mice (Fernández-Ruiz et al., 2010). When both groups of animals were subjected to

transient focal cerebral ischemia or lesioned with kainite, the CB1-receptor-deficient mice

proved to be significantly more vulnerable because they exhibited increased brain damage and

neurological deficits than their wild-type counterparts (Fernández-Ruiz et al., 2010). CB1

receptors also mediated the neuroprotective effects exhibited by WIN55,212-2 in a rat model of

striatal degeneration caused by the excitotoxin quinolinate (Fernández-Ruiz et al., 2010). This

model reproduces the excitotoxic conditions of HD in humans, although there is recent evidence

that CB2 receptors also protect against quinolinate-induced striatal damage. Additionally, it is

possible that CB1 receptors are also involved in the beneficial effects reported for various

cannabinoid agonists against excitotoxicity in the spinal cord in an experimental model of ALS

(Fernández-Ruiz et al., 2010). By contrast, CB1 receptor antagonists by themselves potentiated

excitotoxicity in kainate-injected mice and increased lesion volume in a rat model of HD

generated by mitochondrial toxins (Fernández-Ruiz et al., 2010). However, other studies

reported no effects after the blockade of CB1 receptors or even neuroprotection, in both cases

using neonatal models of excitotoxicity (Fernández-Ruiz et al., 2010). These results also agree

with the neuroprotective function assigned to the post-ischemic downregulation of hippocampal

CB1 receptors found in gerbils, although some authors theorize that the neuroprotective action of

their antagonists might be exerted by mechanisms independent on their ability to block these

receptors (Fernández-Ruiz et al., 2010). Therefore, the issue requires further investigation.

Cannabinoids and oxidative stress

Brain injury in acute or chronic neurodegenerative disorders triggers the accumulation of

toxic products, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS),

which damage proteins, DNA or the lipids that are part of cell membranes, resulting in cell death

(Fernández-Ruiz et al., 2010). Certain cannabinoids that contain phenolic groups in their

chemical structure (such as cannabidiol (CBD), Δ9-THC, cannabinol, nabilone, levonantradol,

and dexanabinol, and AM404), act as potent antioxidant compounds because they are able to

reduce the negative effect of ROS . This antioxidant potential of specific cannabinoids seems to

be cannabinoid-receptor-independent, and possibly act as scavengers of ROS (Fernández-Ruiz et

al., 2010). CBD has an important antioxidant potential and is a plant-derived cannabinoid that it

is not psychoactive due to its negligible affinity at the CB1 receptor. Its antioxidant potency is

superior to the classic dietary antioxidants such as ascorbate and α-tocopherol. Compared with

the psychoactive Δ9-THC found in cannabis, CBD has equivalent antioxidant potential, but has

more advantages as a possible clinical exploitation because it can be used at doses higher than

Δ9-THC since it is not psychoactive. In addition, CBD may be administered for longer periods of

time, compared with Δ9-THC, since it does not produce tolerance (Fernández-Ruiz et al., 2010).

Cannabinoids and blood supply

Brain damage caused by stroke or traumatic injuries is also associated with the generation

of endothelium-derived mediators (e.g., endothelin-1 (ET-1) and nitric oxide), which affect the

local vascular tone. These factors produce vasoconstriction, thus limiting the blood supply to the

injured area and aggravating brain damage (Fernández-Ruiz et al., 2010). Cannabinoid agonists

act as potent modulators of vascular tone, thus further explaining the neuroprotection exerted by

these agonists in stroke and head trauma. Cannabinoids attenuate the ET-1-induced

vasoconstriction and restore blood supply to the injured brain. Rimonabant prevented this effect,

indicating that it is exerted through the activation of CB1 receptors, although CB2 receptors are

also present in brain microvasculature (Fernández-Ruiz et al., 2010). In addition, brain

microvessels also contain measurable levels of endocannabinoids and the biochemical machinery

for their synthesis, transport and degradation. The cellular location of all these elements support

the idea that they play a key role in the transport of endocannabinoids through the blood–brain

barrier (Fernández-Ruiz et al., 2010).

The effects of CB1 and CB2 activation

CB1 Activation: Enhancement of endocannabinoid signaling by fatty acid amide hydrolase

inhibition

Neuronal injury activates cannabinoid signaling in the central nervous system as an

intrinsic neuroprotective response (Hwang et al., 2010). Indirect potentiation of this response

through pharmacological inhibition of FAAH, an endocannabinoid-deactivating enzyme, has

been shown to promote neuronal maintenance and function (Hwang et al., 2010). This

therapeutic modality has the potential to offer site- and event-specific neuroprotection under

conditions where endocannabinoids are being produced as part of a physiological protective

mechanism. (Hwang et al., 2010)

CB2 Activation protects against cerebral ischemia by inhibiting neutrophil recruitment

Activation of the cannabinoid 2 receptor (CB2) reduces ischemic injury in several organs

(Murikinati et al., 2009). However, the mechanisms underlying this protective action are unclear.

In a mouse model of ischemic stroke, the CB2 agonist JWH-133 (1 mg · kg−1 · d−1) decreases

the infarct size measured 3 d after onset of ischemia. The neuroprotective effect of JWH-133 was

lost in CB2-deficient mice, confirming the specificity of JWH-133 (Murikinati et al., 2009).

Analysis of bone marrow chimeric mice revealed that bone marrow-derived cells mediate the

CB2 effect on ischemic brain injury. CB2 activation reduced the number of neutrophils in the

ischemic brain, as shown by FACS analysis and by measuring the levels of the neutrophil marker

enzyme myeloperoxidase (Murikinati et al., 2009). The researchers found in vitro that CB2

activation inhibits adherence of neutrophils to brain endothelial cells. JWH-133 (1 μM) also

interfered with the migration of neutrophils induced by the endogenous chemokine CXCL2 (30

ng/ml) by activating the MAP kinase p38. This effect on neutrophils is likely responsible for the

neuroprotection mediated by JWH-133 because JWH-133 was no longer protective when

neutrophils were depleted (Murikinati et al., 2009).

The CB2 receptor is expressed in some brainstem neurons; in activated microglia,

astrocytes, and endothelial cells; and in peripheral immune cells, providing several potential

mechanisms by which CB2 agonists may protect against nerve cell injury (Murikinati et al.,

2009). Neurons in precerebellar nuclei express CB2 receptors, which mediate a neuroprotective

effect through PI3K/Akt signaling (Murikinati et al., 2009).

Activation of Cannabinoid CB2 Receptor–Mediated AMPK/CREB Pathway Reduces Cerebral

Ischemic Injury

The CB2 receptor was shown to mediate neuroprotection in ischemic injury. However,

the role of CB2 receptors in the central nervous system, especially neuronal and glial CB2Rs in

the cortex, remains unclear (Choi et al., 2013). Anti-ischemic mechanisms of cortical CB2

activation were investigated in various ischemic models. In rat cortical neurons/glia mixed

cultures, the CB2 agonist trans-caryophyllene (TC) decreased neuronal injury and mitochondrial

depolarization caused by oxygen-glucose deprivation/re-oxygenation (OGD/R); these effects

were reversed by the selective CB2 antagonist, AM630, but not by the CB1 antagonist, AM251

(Choi et al., 2013). Although it did not scavenge for ROS or induce antioxidant enzymes, TC

reduced OGD/R-evoked mitochondrial dysfunction and intracellular oxidative stress (Choi et al.,

2013). Western blot analysis demonstrated that TC enhanced phosphorylation of AMP-activated

protein kinase (AMPK) and cAMP responsive element-binding protein (CREB), and increased

expression of the CREB target gene product, brain-derived neurotrophic factor. However, TC

failed to alter the activity of either Akt or extracellular signal–regulated kinase, two major CB2

signaling pathways. Selective AMPK and CREB inhibitors abolished the neuroprotective effects

of TC (Choi et al., 2013). In rats, post-ischemic treatment with TC decreased cerebral infarct size

and edema, and increased phosphorylated CREB and brain-derived neurotrophic factor

expression in neurons. All protective effects of TC were reversed by co-administration with

AM630 (Choi et al., 2013).

Protection following perinatal hypoxic ischemia:

Hypoxic-ischemic encephalopathy (HIE) in newborns is a brain injury caused by oxygen

deprivation in the brain which leads to brain tissue damage. HIE due to fetal or neonatal

asphyxia is a leading cause of death or severe impairment among infants. It can result in cerebral

palsy, epilepsy, developmental delay, motor impairment, neurodevelopmental delay, and

cognitive impairment (Kurinczuk et al., 2010).

Cannabinoids have been found to successfully reduce hypoxic-ischemic brain damage in

newborns (Castillo et al., 2010). In vivo, the synthetic cannabinoid WIN55212 was

neuroprotective when administered following a hypoxic ischemic (HI) episode (Castillo et al.,

2010). However, due to concerns regarding possible long term effects of perinatal exposure to a

psychoactive substance, researchers investigated whether cannabidiol (CBD), a similar non-

psychoactive compound found in cannabis, could also be neuroprotective following HI brain

injury. CBD is known to be a potent anti-inflammatory and antioxidant substance, therefore

interfering with some of the main processes leading to neuronal damage (Castillo et al., 2010).

Other effects of CBD include the inhibition of calcium transport across membranes, inhibition of

anandamide uptake and enzymatic hydrolysis, as well as the inhibition of inducible nitric oxide

synthase (iNOS) protein expression and nuclear factor (NF)-κB activation, all of which

contribute to neuroprotection (Castillo et al., 2010).

To investigate the mechanisms involved in CBD-induced neuroprotection following HIE,

forebrain slices from newborn mice underwent oxygen and glucose deprivation in the presence

of a vehicle or CBD alone with selective antagonists of CB1, CB2, A1 and A2 receptors. CBD

reduced acute and apoptotic HI brain damage by reducing glutamate and IL-6 concentrations and

TNFα, COX-2 and iNOS expression. CBD effects were reversed by the CB2 antagonist AM630

and by the A2A antagonist SCH58261. The A1A antagonist DPCPX only counteracted the CBD

reduction of glutamate release, while the CB1 antagonist SR141716 did not modify any effect of

CBD. Therefore, CBD induces powerful neuroprotection following HI by acting on some of the

major mechanisms responsible for cell death. These effects are mediated mainly by CB2 and

A2A, receptors (Castillo et al., 2010).

Mechanisms of cannabidiol neuroprotection in hypoxic–ischemic newborn pigs: Role of 5HT1A

and CB2 receptors.

The mechanisms underlying the neuroprotective effects of cannabidiol (CBD) were

studied in vivo using a hypoxic–ischemic (HI) brain injury model in newborn pigs. One- to two-

day-old piglets were exposed to HI for 30 min by interrupting carotid blood flow and reducing

the fraction of inspired oxygen to 10%. Thirty minutes after HI, the piglets were treated with

vehicle (HV) or 1 mg/kg CBD, alone (HC) or in combination with 1 mg/kg of the CB2 receptor

antagonist AM630 or the serotonin 5HT1A receptor antagonist WAY100635 (Pazos et al.,

2013). HI decreased the number of viable neurons and affected the amplitude-integrated EEG

background activity as well as the prognostic proton-magnetic-resonance-spectroscopy (H±-

MRS)-detectable biomarkers lactate/N-acetylaspartate and N-acetylaspartate/choline ratios

(Pazos et al., 2013). CBD administration after HI prevented all these alterations, although this

CBD-mediated neuroprotection was reversed by co-administration of either WAY100635 or

AM630, suggesting the involvement of CB2 and 5HT1A receptors (Pazos et al., 2013). Lastly,

bioluminescence resonance energy transfer studies indicated that CB2 and 5HT1A receptors may

form heteromers in living HEK-293T cells.

Further evidence for neuroprotective effects of cannabinoids

Cerebroprotective effects of TAK-937

TAK-937 is a selective and highly potent CB1/CB2 receptor agonist (Suzuki et al.,

2012). The effect of TAK-937 on ischemic brain damage was examined in rat and monkey

ischemic stroke models. Sprague–Dawley rats were subjected to 2 h transient middle cerebral

artery occlusion (t-MCAo) by inserting an intraluminal suture. TAK-937 was administered

intravenously for 24 h starting 2 h after MCAo. Infarct volume was determined 24 h after

MCAo. Functional outcomes and brain atrophy were also evaluated 4 weeks after MCAo. Next,

cynomolgus monkeys were subjected to thromboembolic MCAo. TAK-937 was administered

intravenously for 24 h starting 0.5 h after MCAo. Infarct volume and cerebrospinal fluid (CSF)

S-100ß levels were determined (Suzuki et al., 2012). In the rat t-MCAo model, TAK-937

significantly reduced the infarct volume in male, female and ovariectomized rats and also

improved functional outcomes and brain atrophy (Suzuki et al., 2012). In the monkey

thromboembolic MCAo model, TAK-937 showed trend to reduce the infarct volume and S-100ß

levels in CSF by 40%. S-100ß levels in CSF were positively correlated with infarct volume

(Suzuki et al., 2012). These results suggest that TAK-937 could be useful for treatment of acute

ischemic stroke. S-100ß levels would also be a useful surrogate biomarker for development of

TAK-937 (Suzuki et al., 2012).

CB1 AND CB2 receptors mediate long-lasting neuroprotection and improve motor behavior

deficits after transient focal cerebral ischemia

The endocannabinoid system is crucially involved in the regulation of brain activity and

inflammation. The localization of cannabinoid CB1 and CB2 receptors in adult rat brains before

and after focal cerebral ischemia due to endothelin-induced transient occlusion of the middle

cerebral artery (eMCAO) was investigated using immunohistochemistry and both receptor

subtypes were identified in cortical neurons (Schmidt et al., 2012). After eMCAO, neuronal cell

death was accompanied by reduced neuronal CB1 and CB2 receptor-linked immunofluorescence

(Schmidt et al., 2012). The CB1 receptor was found in activated microglia/macrophages 3 days

post eMCAO and in astroglia cells at days 3 and 7 (Schmidt et al., 2012). CB2 receptor labeling

was identified in activated microglia/macrophages or astroglia 3 and 7 days post ischemia,

respectively (Schmidt et al., 2012). In addition, immune competent CD45-positive cells were

characterized by pronounced CB2 receptor staining 3 and 7 days post eMCAO (Schmidt et al.,

2012). When applied consecutively before, during and after eMCAO, the selective CB1 and CB2

receptor agonist KN38-72717 revealed a significant dose-dependent and long-lasting reduction

of cortical lesion sizes due to eMCAO (Schmidt et al., 2012). Additionally, severe motor deficits

of animals suffering from eMCAO were significantly improved by KN38-7271 (Schmidt et al.,

2012). KN38-7271 remained effective, even if its application was delayed up to 6 h post

eMCAO (Schmidt et al., 2012).

Conclusions

The pathophysiology of brain damage after ischemic stroke involves a number of

mechanisms leading to neuronal damage such as the excessive release of glutamate and

inflammatory reactions. Cannabinoid receptor agonists seem to alleviate ischemic brain damage

by modulating neurotransmission and neuroinflammatory responses via CB1 and CB2 receptors.

Among their vast pharmacological effects, cannabinoids have proven to be potentially

useful neuroprotective molecules and therapeutic agents. The cellular and molecular mechanisms

involved in these neuroprotective effects are: i) to attenuate excitotoxicity exerted either by

inhibiting glutamate release or by blocking glutamatergic receptors; ii) to reduce intracellular

calcium levels, particularly by closing voltage-dependent channels for this ion; iii) to reduce

oxidative stress by acting as scavengers of ROS, a property independent of cannabinoid receptors

and restricted to specific classic cannabinoids; iv) to reduce local inflammatory events by acting

predominantly through the activation of CB2 receptors located on glial elements and through

nuclear receptors PPARs; and v) to restore blood supply to injured area by reducing the

vasoconstriction produced by several endothelium-derived factors. Through one or more of these

processes, cannabinoids may provide neuroprotection in conditions of acute or accidental

neurodegeneration, such as those of ischemic or traumatic injury. They can also be used to delay

or stop the progression of neurodegeneration in chronic diseases affecting cognitive processes

such as AD, PD, HD, ALS or MS. Most of this information is still preclinical and frequently too

limited, but this area of research is expected to continue to from the present preclinical evidence

to a clinical application. Although the vast benefits of cannabinoids have been widely known, the

field of medical cannabis has seen obstacles mostly due to the laws surrounding cannabis

impeding research. As legal issues regarding medical marijuana continue to be resolved in many

parts of the world, researchers are fully able to research these compounds. This will provide

physicians with the necessary volume of reputable evidence needed to make informed decisions

about prescribing cannabis and cannabinoids to their patients for many conditions. This will

significantly improve care for many individuals who do not respond to other medications and

provide patients with additional options in their treatment plan.

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