CB1 Receptors in the Anterior Piriform Cortex Control Odor Preference Memory

Abstract

Highlights d CB1 receptors are highly expressed in anterior piriform cortex (aPC) interneurons d aPC-CB1 receptors control retrieval of conditioned odor preference (COP) d aPC-CB1 receptors are not involved in retrieval of conditioned odor aversion d COP retrieval is linked to CB1-dependent reduction of aPC inhibitory transmission

Behavioral and Neurobiological Convergence of Odor, Mood and Emotion: A Review

“…It has been hypothesized that the PCX merges odorant features extracted by the receptors and olfactory bulb into perceptual odor objects (Haberly, 2001;Wilson and Sullivan, 2011), providing for both odor quality coding (e.g., rose) and odor categorization (e.g., floral; Kadohisa and Wilson, 2006;Howard et al, 2009). The PCX performs this odor object construction in an experiencedependent manner and is critically involved in odor memory (Calu et al, 2007;Sacco and Sacchetti, 2010;Meissner-Bernard et al, 2019;Terral et al, 2019;Zhang et al, 2019).…”

Cannabinoid Control of Olfactory Processes: The Where Matters

“…In the anterior PC (aPC), CB1 receptors were mainly described at GABAergic synapses, where they modulate inhibitory transmission and plasticity [37,40]. Moreover, depending on CB1 receptors in the aPC, the retrieval of appetitive, but not aversive, olfactory memory is associated with a modulation of local inhibitory transmission onto specific principal cells in the aPC [37]. These data indicate that CB1 receptors in the aPC selectively control olfactory memory retrieval related to positively motivated behaviors.…”

“…However, although relatively high levels of CB1 receptors were described in the 1990s in many olfactory brain areas of rodents [20][21][22][23], their olfactory-related functions only started to be studied during the last decade. Notably, the involvement of CB1 receptors in specific odor-related processes has been reported in specialized olfactory structures such as the olfactory epithelium (OE; [24][25][26][27]), the main olfactory bulb (MOB; [18,[28][29][30][31][32][33][34]), and the piriform cortex (PC; [35][36][37][38][39][40]), but also in other brain areas processing olfactory information [41][42][43][44]. For the sake of clarity in this review, we will focus on describing the role of the ECS, particularly CB1 receptor signaling, in specific main olfactory areas (i.e., OE, MOB, and PC).…”

“…Despite the possible post-synaptic CB1 receptors' localization, or that endocannabinoids can modulate directly postsynaptic GABAergic receptors [55], further experiments will determine how CB1 receptor activation allows for controlling GABAergic conductance in the pPC. In the anterior PC (aPC), CB1 receptors were mainly described at GABAergic synapses, where they modulate inhibitory transmission and plasticity [37,40]. Moreover, depending on CB1 receptors in the aPC, the retrieval of appetitive, but not aversive, olfactory memory is associated with a modulation of local inhibitory transmission onto specific principal cells in the aPC [37].…”

Specific hippocampal interneurons shape consolidation of recognition memory

“…Cells expressing mRNAs were quantified in the different layers (stratum oriens, stratum pyramidale, stratum radiatum and stratum lacunosum moleculare) of the dorsal hippocampus. CB1 positive cells were classified according to the level of transcript visualized by the intensity of fluorescence (Marsicano and Lutz, 1999;Terral et al, 2019). ''High-CB1'' cells were considered to be roundshaped and intense staining covering the entire nucleus whereas ''Low-CB1'' cells were defined with discontinuous shape and lowest intensity of fluorescence allowing the discrimination of grains of staining.…”