Recent advances in cannabinoid-based therapies identified the natural CB2 receptor agonist β-caryophyllene (BCP) as a promising anti-inflammatory and neuroprotective agent. To further explore its therapeutic potential on the management of neurodegenerative disorders, in the present study we investigated the ability of BCP to prevent neuroinflammation and promote neuroprotection by using both in vitro and ex vivo models of β-amyloid induced neurotoxicity. Our data showed that BCP significantly protected human microglial HMC3 cells from Aβ25-35-induced cytotoxicity, reducing the release of pro-inflammatory cytokines (TNF-α, IL-6) while enhancing IL-10 secretion. These effects were associated with a reduced activation of the NF-κB pathway, which emerged as a central mediator of BCP action. Notably, the use of CB2R- or PPARγ-selective antagonists revealed that the observed NF-κB inhibition by BCP may involve the coordinated activation of both canonical (e.g., CB2R) and non-canonical (e.g., PPARγ) receptors. Moreover, BCP restored the expression of SIRT1, PGC-1α, and BDNF, indicating the involvement of neurotrophic pathways. Clear neuroprotective properties for BCP have been highlighted in Aβ1-42-treated brain slice preparations, where BCP demonstrated the rescue of both the amyloid-dependent depression of BDNF expression and long-term synaptic potentiation (LTP) impairment. Overall, our results suggest that BCP constitutes an attractive natural molecule for the treatment of Aβ-induced neuroinflammation and synaptic dysfunction, warranting further exploration for its clinical application.
Memory is proposed to depend on neuronal ensembles distributed across multiple brain regions, yet how episodic-like memories are organized across the brain remains unclear. Here we investigated the brain-wide organization of object-place-context (OPC) memory in mice. By mapping c-Fos activation across the brain during memory recall and comparing it to multiple control conditions, we identified a set of brain regions selectively engaged during episodic-like memory retrieval, consistent with the recruitment of a fronto-posterior medial network. Chemogenetic manipulation of learning-activated neuronal ensembles revealed that the selected brain regions are necessary for memory retrieval. Within this network, the retrosplenial cortex emerged as a key region required for successful memory recall, with neuronal ensembles exhibiting properties of engram cells. Electrophysiological recordings during recall revealed distinct novelty-related dynamics across regions. In mPFC, theta power increased during novel exploration, while firing rate increased both immediately before and during interaction with the novel object configuration. In RSP, novelty was associated with a sharp increase in firing rate during exploration. Together, our findings suggest a distributed organization supporting episodic-like memory retrieval in mice, in which a posterior-medial network is activated and necessary for a successful behavioral expression.