Modulation of spatial learning and memory by cannabinoid-estrogen interaction in an AD-like cognitive impairment: The role of cannabinoid receptors and BDNF protein

A 2026 study found that a THC-standardized marijuana extract improved spatial learning and memory in an Alzheimer’s-like model of cognitive impairment. Researchers tested the extract in rats exposed to amyloid-beta, a protein closely associated with Alzheimer’s disease, and observed improvements in memory performance.

The cognitive improvements were accompanied by changes in cannabinoid receptor signaling and in BDNF, or brain-derived neurotrophic factor, a protein that supports neuron survival, brain plasticity, learning, and memory. The findings suggest that the brain’s cannabinoid system and BDNF may be involved in the neuroprotective-like effects observed with the THC-standardized extract.

The researchers also examined the interaction with estrogen and found that adding estradiol did not produce an additional synergistic improvement. As the authors concluded, “These preclinical findings suggest that a THC-standardized marijuana extract may exert neuroprotective-like effects in an AD-like cognitive impairment model.”

“Alzheimer’s disease (AD) is an increasingly prevalent neurodegenerative disorder worldwide, with women showing a higher risk of developing the disease. The decline in steroid hormones after menopause may contribute to the increased susceptibility of women to neurodegenerative conditions.

In parallel, cannabis-derived compounds have been reported to alleviate certain symptoms associated with neurological disorders. The present study was designed to investigate the effects of marijuana extract on cognitive impairment and hippocampal molecular markers in an ovariectomized AD-like rat model, and to evaluate whether co-administration with estradiol modifies these effects.

The marijuana extract used in this study was characterized by HPLC and was found to contain 8.5% Δ9-THC. AD-like cognitive impairment pathology was induced by intra-hippocampal administration of Aβ25-35 in OVX rats. Animals were treated with marijuana extract (60 mg/kg/day, corresponding to approximately 5.1 mg/kg/day Δ9-THC) either alone or in combination with 17β-estradiol (1 mg/kg every 4 days) for 28 days. Cognitive performance was evaluated using the Morris water maze (MWM). In addition, hippocampal CB1/CB2 receptor expression and BDNF protein levels were measured to examine potential molecular associations.

Our findings showed that chronic administration of the marijuana extract improved Aβ25-35-induced deficits in spatial learning and memory.

Alterations in CB1 receptor expression and BDNF levels accompanied these behavioral effects. Notably, co-treatment with estradiol did not produce a synergistic effect, suggesting a complex interaction between cannabinoid-related and estrogen-related signaling pathways.

These preclinical findings suggest that a THC-standardized marijuana extract may exert neuroprotective-like effects in an AD-like cognitive impairment model. However, because the extract was not fully phytochemically characterized and the mechanistic analyses were correlational, the results should be interpreted cautiously. Further studies are needed to clarify the underlying mechanisms and translational relevance of these findings.”

https://pubmed.ncbi.nlm.nih.gov/42756662

“In conclusion, chronic administration of THC-standardized marijuana extract improved spatial learning and memory performance in the AD-like cognitive impairment model, and these behavioral changes were accompanied by alterations in hippocampal CB1/CB2 gene expression and BDNF protein levels.”

https://www.ibroneuroreports.org/article/S2667-2421(26)00149-1/fulltext

Cannabinoids in Cancer: Molecular Mechanisms of Tumor Cell Death and Translational Opportunities

Cannabinoids can attack cancer cells through far more than a single mechanism. This 2026 review describes how natural and synthetic cannabinoids can suppress tumor-cell growth, angiogenesis and metastasis while activating multiple forms of regulated cancer-cell death, including apoptosis, autophagy-dependent cell death, necroptosis, ferroptosis and parthanatos.

The researchers detail an interconnected network of molecular pathways affected by cannabinoids, including PI3K/AKT/mTOR, MAPK/ERK, NF-κB, TRIB3/AKT/mTORC1 and ceramide/ROS signaling. These pathways control whether cancer cells survive, proliferate, respond to stress or undergo programmed destruction, giving cannabinoids multiple potential points of attack against malignant cells.

The review also finds that cannabinoids may enhance conventional anticancer treatments by engaging complementary cell-death pathways. The authors conclude that cannabinoids represent promising anticancer agents and therapeutic adjuvants, with much of the direct anticancer evidence still coming from preclinical research and clinical translation now depending on better dosing, formulations and controlled human studies.

“Cannabinoids are terpenophenolic compounds derived from Cannabis sativa L. that exert a broad range of biological and pharmacological activities. Increasing evidence highlights their potential as modulators of cancer progression specifically through the suppression of tumor cell growth, angiogenesis, and metastasis across multiple tumor models.

This review provides a comprehensive overview of the molecular mechanisms by which natural and synthetic cannabinoids induce regulated cancer cell death.

Current evidence demonstrates that cannabinoids regulate multiple forms of cancer cell death, including apoptosis, autophagy-dependent cell death, necroptosis, ferroptosis, and parthanatos. These effects are mediated through complex and interconnected signaling pathways such as TRIB3/AKT/mTORC1, PI3K/AKT/mTOR, MAPK/ERK, NF-κB, ERK/JNK/p38-MAPK, and ceramide/Raf1/ERK/ROS.

In addition to their direct antitumor effects, cannabinoids can enhance the efficacy of conventional anticancer therapies through the coordinated regulation of complementary cell death pathways. They also provide clinically relevant supportive benefits in palliative care, alleviating chemotherapy-induced nausea, cachexia, and mood or sleep disturbances.

Collectively, these findings identify cannabinoids as promising anticancer agents and therapeutic adjuvants, predominantly in the preclinical setting. However, significant challenges remain regarding their safety, optimal dosing, formulation, and clinical efficacy. Further mechanistic studies, rigorous preclinical research, and well-designed clinical trials are required to establish the translation of cannabinoid-based therapies into precision oncology.”

https://pubmed.ncbi.nlm.nih.gov/42793092

“The cannabis plant, a member of the Cannabaceae family, has been traditionally utilized for centuries for spiritual and remedial healing.”

“The anticancer activity of cannabinoids was discovered in 1975 by Munson et al.. Cannabinoids suppress cancer cell proliferation, angiogenesis, tumor invasion, metastasis, and stemness while inducing different modes of cell death pathways.”

“In summary, this review highlights the growing body of evidence supporting the ability of cannabinoids to induce multiple forms of cell death across a broad spectrum of cancer types. Through the modulation of diverse molecular and signaling pathways, cannabinoids have emerged as promising anticancer agents, mostly in preclinical models, with the potential to target tumor growth, survival, and progression, ultimately triggering diverse cell death mechanisms.”

https://www.mdpi.com/2218-273X/16/9/1260

(+)-Trans-Cannabidiol Is an Agonist at Human CB2 Receptors

A new 2026 study reports that (+)-trans-cannabidiol [(+)-CBD] acts as an agonist at human CB2 cannabinoid receptors, activating a major receptor of the endocannabinoid system involved in immune and inflammatory signaling.

Researchers found that (+)-CBD produced a strong, concentration-dependent CB2 response, reaching roughly 90% of the maximum effect produced by the reference cannabinoid agonist CP55940. Additional testing indicated that the compound acts through the receptor’s primary, or orthosteric, binding site.

The findings show that different molecular forms of cannabidiol can interact with cannabinoid receptors in very different ways. The researchers conclude that (+)-CBD may deserve further study in CB2-sensitive disease states, adding another layer to our understanding of how cannabinoid chemistry can influence the human endocannabinoid system.

“(-)-trans-Cannabidiol ((-)-CBD) is a principal phytocannabinoid from Cannabis sativa. (-)-CBD has complex pharmacology but is a relatively weak inhibitor of CB1 and CB2 receptor signaling. Cannabidiol has two chiral centres and thus four stereoisomers. (+)-trans-CBD ((+)-CBD) has a higher affinity than (-)-CBD at CB1 and CB2, but its pharmacodynamic effects at these receptors are incompletely described.

We examined the activity of (+)-CBD at human CB1 and CB2 receptors using a fluorescence-based assay of membrane potential in AtT20 cells stably expressing CB1 or CB2 receptors.

(+)-CBD produced a rapid, concentration-dependent hyperpolarization in CB2-expressing cells (pEC50 6.63 ± 0.08) with a maximal effect 90% of the response to CP55940. The CB2 response was blocked by pertussis toxin pretreatment and competitively inhibited by the CB2 antagonist AM630 (Schild slope 1.1 ± 0.1). (+)-CBD was a low-efficacy, low-potency CB1 agonist and inhibited somatostatin-receptor effects at high concentrations (10-30 μM). (+)-CBD had no effect on the membrane potential of AtT20 wild-type cells. In silico modeling of ligand interactions with CB2 indicated that (+)-CBD but not (-)-CBD formed an H-bond with Ser285, a residue crucial for agonist activation of CB2.

Our data suggests (+)-CBD acted as a CB2 agonist via the orthosteric binding site on the receptor. Synthetic CBD, including (+)-CBD, has previously been administered in clinical trials, presumably without consideration of its potential CB2 agonist activity.

Given the relative safety of (-)-CBD in people, (+)-CBD may be a useful drug to explore CB2-sensitive disease states.”

https://pubmed.ncbi.nlm.nih.gov/42745361

“This study emphasizes the importance of understanding the molecular actions of the enantiomers of chiral cannabinoids. Although the safety of (+)-CBD cannot simply be assumed to be the same as (−)-CBD, the identification of (+)-CBD as a robust CB2 agonist suggests that (+)-CBD may be worth exploring as a therapeutic agent in chronic inflammatory conditions or other diseases where CB2 activation may prove beneficial.”

https://bpspubs.onlinelibrary.wiley.com/doi/10.1002/prp2.70325

An Ultra-Low Dose of ∆9-Tetrahydrocannabinol Alleviates Alzheimer’s Disease-Related Cognitive Impairments and Modulates TrkB Receptor Expression in a 5XFAD Mouse Model

An ultra-low dose of Δ9-THC improved Alzheimer’s disease-related cognitive impairment in 5xFAD mice, including animals treated after memory problems were already established. The study found improvements in learning and memory without relying on repeated high-dose THC exposure.

The researchers also found changes in TrkB receptor expression, a signaling pathway closely tied to brain plasticity, learning, memory, and neuronal survival. These changes suggest that THC’s effects may involve more than temporary symptom relief and may influence mechanisms connected to cognitive function.

The findings add to a growing body of preclinical research showing that very low doses of THC can produce different biological effects than higher doses, particularly in the aging and Alzheimer’s-disease brain. In this model, a single ultra-low dose was enough to improve cognitive performance and alter a key neurotrophic signaling pathway.

“Alzheimer’s disease (AD) is the most common form of dementia, but there is still no available treatment.

Δ9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent.

Using THC in conventional high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice.

Here, 5xFAD AD model mice received a single treatment of ULD-THC (0.002 mg/kg) after disease onset and were examined in two separate experiments for cognitive functions, neurotropic, and inflammatory factors in the hippocampus.

We show that a single injection of ULD-THC alleviated cognitive impairments in 6- and 12-month-old 5xFAD mice. On the biochemical level, our results indicate an imbalance between the truncated TrkB receptor isoform and the full receptor, with AD mice showing a greater tendency to express the truncated receptor, and ULD-THC improved this imbalance. We also investigated the expression of three AD-related inflammatory markers and found an ameliorating effect of ULD-THC.

The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset.”

https://pubmed.ncbi.nlm.nih.gov/36012711

“The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset. As THC is a cheap, widely available substance already approved for use in other conditions, this research brings us closer to understanding its mechanisms and will possibly lead to new treatments.”

https://www.mdpi.com/1422-0067/23/16/9449/htm

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Δ9-Tetrahydrocannabinol treatment impairs CD8+ T cell differentiation into interferon gamma-competent CD45RO+ cells

New research published in The Journal of Pharmacology and Experimental Therapeutics shows that Δ9-tetrahydrocannabinol (THC) can alter the development of CD8+ T cells involved in inflammatory immune responses. Researchers found that THC reduced secretion of interferon gamma (IFNγ), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNFα), three signaling molecules involved in immune activation and inflammation.

Rather than simply preventing cells from producing IFNγ, THC appeared to change how the T cells developed. THC reduced the differentiation of CD8+ T cells into mature CD45RO+ cells capable of secreting IFNγ. A selective CB2 receptor agonist produced similar effects, suggesting that activation of the cannabinoid CB2 receptor may play an important role in THC’s immune-modulating activity.

The researchers examined these effects partly because IFNγ-producing CD8+ T cells contribute to persistent neuroinflammation associated with HIV-associated neurocognitive disorders. They concluded that reducing CD8+ T-cell-derived IFNγ in the central nervous system may potentially improve cognitive outcomes during HIV infection, while noting that the findings may also have relevance to other inflammatory diseases involving IFNγ-producing CD8+ T cells.

“Chronic human immunodeficiency virus (HIV) infection results in a persistent state of neuroinflammation, even with combined antiretroviral therapy. Neuroinflammation contributes to pathology termed HIV-associated neurocognitive disorder, which is exacerbated by interferon gamma (IFNγ)-producing CD8+ T cells in the central nervous system.

Many people living with HIV self-report using Cannabis sativa to mitigate symptoms of chronic infection and side effects of treatment. C. sativa is composed of various phytocannabinoids, including Δ9-tetrahydrocannbinol (THC), which possesses immune-modulating properties.

This study aims to determine whether C. sativa use by people living with HIV, and specifically THC, affects IFNγ secretion by CD8+ T cells.

We found that HIV status does not influence T cell IFNγ responses, and C sativa use modestly reduces the average secretion of IFNγ by CD8+ T cells from HIV+ donors. Treatment of CD8+ T cells with THC and the selective cannabinoid receptor 2 agonist, JWH-015, reduced T-cell cytokine secretion, with THC eliciting greater suppression than cannabidiol.

These results suggest that THC treatment does not directly impair IFNγ gene expression or protein production, as determined by polymerase chain reaction and flow cytometry. However, THC treatment impaired CD8+ T cell differentiation into IFNγ-competent CD45RO+ cells.

These studies are of clinical relevance because reduction of CD8+ T-cell-derived IFNγ in the central nervous system may improve cognitive outcomes during HIV infection. Furthermore, these findings may be generalizable to other inflammatory diseases in which IFNγ-producing CD8+ T cells have been implicated.

SIGNIFICANCE STATEMENT: Δ9-Tetrahydrocannbinol (THC) treatment reduces CD8+ T cell interferon gamma (IFNγ) secretion isolated from HIV- and HIV+ individuals. THC and the selective cannabinoid receptor 2 agonist, JWH-015, both reduced CD8+ T cell secretion of IFNγ, interleukin 2, and tumor necrosis factor α, suggesting the involvement of cannabinoid receptor 2. Although THC treatment does not suppress IFNγ mRNA or protein levels, it reduces the number of IFNγ-secreting cells by impairing CD8+ T-cell differentiation into IFNγ-competent CD45RO+ cells.”

https://pubmed.ncbi.nlm.nih.gov/42748512

https://jpet.aspetjournals.org/article/S0022-3565(26)01210-3/abstract

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Medical Cannabis and the Hallmarks of Cancer: A Critical Narrative Review

A 2026 critical narrative review examines medical cannabis through one of the most important frameworks in cancer biology: the hallmarks of cancer. Rather than looking only at symptom relief, the authors reviewed evidence for how cannabinoids, including THC and CBD, may interact with biological processes that allow cancer to develop, survive, grow and spread.

The review discusses cannabinoid effects involving cancer-cell proliferation, programmed cell death, angiogenesis, invasion, metastasis, tumor metabolism, immune responses and the tumor microenvironment. It also examines major cancer-related signaling pathways, including PI3K/AKT, RAS/RAF/ERK, mTOR, EGFR, Wnt/β-catenin and p53.

Taken together, the research shows that cannabinoids can influence multiple hallmarks of cancer through several interconnected mechanisms. The authors describe the evidence as showing biologically plausible antitumor activity and highlight cannabinoids as an important area for continued cancer research and development.

“Cancer remains a highly complex and heterogeneous disease, causing major morbidity and mortality worldwide despite advances in diagnosis and treatment. The hallmarks of cancer enlighten the biological mechanisms supporting tumourigenesis and malignant evolution, while helping to identify potential therapeutic targets.

Medical cannabis has mostly been used in oncology for supportive care, but increasing preclinical evidence suggests interference with cancer-related signalling pathways.

This narrative review summarizes the current evidence on cannabinoids, in particular the phytocannabinoids cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), framing their prospective anticancer effects in the hallmarks of cancer.

Preclinical studies imply that CBD exerts antiproliferative effects by modulating oncogenic signalling pathways, including EGFR, PI3K/AKT, RAS/RAF/ERK, mTOR and Wnt/β-catenin, while also influencing tumour suppressor pathways involving p53, p21 and p27, causing cell cycle arrest. CBD has additionally been shown to promote programmed cell death via mitochondrial dysfunction and autophagy, altering cancer metabolism as well. Furthermore, CBD has shown anti-invasive and antiangiogenic properties and also appears to modulate immune responses and interactions with the tumour microenvironment, including emerging links with the microbiome.

Overall, cannabinoids exhibit biologically plausible antitumour activity across multiple cancer hallmarks and may present promising candidates for combination therapeutic strategies.

Nonetheless, the current evidence remains predominantly preclinical, and robust translational studies and clinical trials are needed to clarify their pharmacokinetic and pharmacodynamic profiles, determine their clinical efficacy and safety while assessing their potential integration into multimodal cancer treatment.”

https://pubmed.ncbi.nlm.nih.gov/42737454/

“Cannabinoids have demonstrated biologically plausible promising antitumour effects by interacting with several cancer hallmarks, including tumour angiogenesis, resistance to programmed cell death, metastasis and invasion, as well as immune evasion and phenotypic plasticity.”

“Cannabinoids can interfere with several biological mechanisms involved in cancer development and progression and even though their role in oncology remains mostly supportive with predominance in symptom control, preclinical studies increasingly suggest that cannabis can also influence tumour biology.”

https://www.mdpi.com/1422-0067/27/17/7549

Combined Cannabidiol and Δ9-Tetrahydrocannabinol Modulate Inflammation and Nociceptive Signaling in Human Dental Pulp Cells

A new study using human dental pulp cells found that combining cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) produced stronger anti-inflammatory effects than either cannabinoid alone. The combination reduced the pro-inflammatory cytokines IL-6, IL-12, and IL-1β while increasing the anti-inflammatory cytokine IL-10.

CBD and THC together also influenced important pathways involved in pain signaling and healing. Researchers reported increased expression of the cannabinoid receptors CNR1 and CNR2, modulation of TRPV1, and enhanced cell proliferation and migration. The combination also promoted mineralized nodule formation and increased markers associated with odontogenic differentiation and new blood-vessel formation.

The researchers concluded that combined CBD and THC show promise for promoting dental pulp healing by simultaneously influencing inflammation, nociceptive signaling, tissue repair, angiogenesis, and cell migration. The findings provide new evidence that cannabinoids may have potential applications in future vital pulp therapies designed to preserve and regenerate living dental tissue.

“Introduction: Dental pulp inflammation, caused by caries, trauma, or restorative operations, produces pain and slows regeneration. Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), cannabinoids of Cannabis sativa, have effects on inflammation and pain relief. However, the impact of these factors on dental pulp healing is not understood. This study investigated the combined effects of CBD and THC in controlling inflammation and nociception during dental pulp repair.

Methods: Human dental pulp cells were stimulated with lipopolysaccharide (LPS) and treated with CBD (2.5 μg/mL), THC (0.6 μg/mL), and their combination. Pro-inflammatory cytokines (IL-6, IL-12 and IL-1β) and anti-inflammatory cytokine IL-10 were analysed using qPCR and ELISA, while anti-nociceptive markers (CNR1, CNR2, and TRPV1) were evaluated by qPCR and Western blot. Cell viability, proliferation, and migration assays were performed to evaluate treatment effects on cellular behaviours associated with pulpal repair and regenerative potential.

Results: Compared with either treatment alone, the CBD/THC combination more effectively attenuated pro-inflammatory cytokines IL-6, IL-12, and IL-1β, enhanced CNR1 and CNR2 expression, modulated TRPV1, and increased IL-10 expression. Viability assays determined optimal non-cytotoxic concentrations for treatment. The combination enhanced cell proliferation and migration, promoted mineralized nodule formation, and significantly upregulated markers associated with tissue repair, odontogenic differentiation (DMP1), and angiogenesis (VEGF and bFGF).

Conclusion: Combined CBD and THC show promise for promoting dental pulp healing by modulating inflammation and nociceptive signaling, while supporting odontogenic differentiation, angiogenesis, and cell migration in human dental pulp cells. These findings provide in vitro evidence supporting combined cannabinoid treatment as a therapeutic strategy for vital pulp therapies.”

https://pubmed.ncbi.nlm.nih.gov/42722230

https://www.jendodon.com/article/S0099-2399(26)00500-5/abstract

∆9-Tetrahydrocannabinol Increases Growth Factor Release by Cultured Adipose Stem Cells and Adipose Tissue in vivo

Δ9-THC increased the release of growth factors from cultured adipose-derived stem cells and from adipose tissue in vivo. These growth factors are involved in processes such as cell survival, tissue repair, blood-vessel formation, and regeneration.

The researchers found that THC changed the secretory activity of adipose stem cells rather than simply affecting their growth. This suggests that THC may influence how these cells communicate with surrounding tissue and support repair through the factors they release.

The findings point to a potential role for THC in regenerative signaling and tissue-healing biology, particularly through adipose-derived stem cells and the local tissue environment. The study adds another dimension to cannabinoid research by showing that THC can affect not just mature cells, but also the reparative signals produced by stem-cell populations.

“Background: Because of its biocompatibility and its soft and dynamic nature, the grafting of adipose tissue is regarded an ideal technique for soft-tissue repair. The adipose stem cells (ASCs) contribute significantly to the regenerative potential of adipose tissue, because they can differentiate into adipocytes and release growth factors for tissue repair and neovascularization to facilitate tissue survival. The present study tested the effect of administering a chronic low dose of ∆9-tetrahydrocannabinol (THC) on these regenerative properties, in vitro and in vivo.

Methods: Human ASCs were exposed to increasing concentrations of THC. Resazurin conversion was applied to investigate the effect on metabolic activity, cell number was assessed by crystal violet staining, tri-linear differentiation was evaluated by specific colorimetric approaches, and the release of growth factors was analyzed by ELISA. Two groups of mice were treated daily either with a low dose of THC (3 mg/kg) or a vehicle solution. After 3 weeks, adipose tissue was obtained from excised fat deposits, homogenized and tested for growth factor contents.

Results: THC decreased ASC proliferation but increased metabolic activity as well as adipogenic and chondrogenic differentiation. A low concentration of THC (1 µM) enhanced the growth factor release by ASCs. The concentration of these cytokines was also increased in adipose tissue of mice treated with THC.

Conlusion: Our results indicate that chronic activation of the endocannabinoid system promoted differentiation and growth factor release of ASCs, which could be of specific value for enhancing the regenerative potential of adipose tissue.”

https://pubmed.ncbi.nlm.nih.gov/39825991/

“Our findings may offer a new approach for improved application of adipose tissue in regenerative medicine.”

https://link.springer.com/article/10.1007/s13770-024-00692-8

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An Ultra-Low Dose of ∆9-Tetrahydrocannabinol Alleviates Alzheimer’s Disease-Related Cognitive Impairments and Modulates TrkB Receptor Expression in a 5XFAD Mouse Model

An ultra-low dose of Δ9-THC improved Alzheimer’s disease-related cognitive impairment in 5xFAD mice, including animals treated after memory problems were already established. The study found improvements in learning and memory without relying on repeated high-dose THC exposure.

The researchers also found changes in TrkB receptor expression, a signaling pathway closely tied to brain plasticity, learning, memory, and neuronal survival. These changes suggest that THC’s effects may involve more than temporary symptom relief and may influence mechanisms connected to cognitive function.

The findings add to a growing body of preclinical research showing that very low doses of THC can produce different biological effects than higher doses, particularly in the aging and Alzheimer’s-disease brain. In this model, a single ultra-low dose was enough to improve cognitive performance and alter a key neurotrophic signaling pathway.

“Alzheimer’s disease (AD) is the most common form of dementia, but there is still no available treatment.

Δ9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent.

Using THC in conventional high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice.

Here, 5xFAD AD model mice received a single treatment of ULD-THC (0.002 mg/kg) after disease onset and were examined in two separate experiments for cognitive functions, neurotropic, and inflammatory factors in the hippocampus.

We show that a single injection of ULD-THC alleviated cognitive impairments in 6- and 12-month-old 5xFAD mice. On the biochemical level, our results indicate an imbalance between the truncated TrkB receptor isoform and the full receptor, with AD mice showing a greater tendency to express the truncated receptor, and ULD-THC improved this imbalance. We also investigated the expression of three AD-related inflammatory markers and found an ameliorating effect of ULD-THC.

The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset.”

https://pubmed.ncbi.nlm.nih.gov/36012711/

“The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset. As THC is a cheap, widely available substance already approved for use in other conditions, this research brings us closer to understanding its mechanisms and will possibly lead to new treatments.”

https://www.mdpi.com/1422-0067/23/16/9449/htm

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Spinal astroglial cannabinoid receptors control pathological tremor

Nature Neuroscience“Cannabinoids reduce tremor associated with motor disorders induced by injuries and neurodegenerative disease. Here we show that this effect is mediated by cannabinoid receptors on astrocytes in the ventral horn of the spinal cord, where alternating limb movements are initiated. We first demonstrate that tremor is reduced in a mouse model of essential tremor after intrathecal injection of the cannabinoid analog WIN55,212-2. We investigate the underlying mechanism using electrophysiological recordings in spinal cord slices and show that endocannabinoids released from depolarized interneurons activate astrocytic cannabinoid receptors, causing an increase in intracellular Ca2+, subsequent release of purines and inhibition of excitatory neurotransmission. Finally, we show that the anti-tremor action of WIN55,212-2 in the spinal cords of mice is suppressed after knocking out CB1 receptors in astrocytes. Our data suggest that cannabinoids reduce tremor via their action on spinal astrocytes.”

https://pubmed.ncbi.nlm.nih.gov/33737752/

https://www.nature.com/articles/s41593-021-00818-4

“Medical cannabis can reduce essential tremor: Turns on overlooked cells in central nervous system”  https://www.sciencedaily.com/releases/2021/03/210319125519.htm