Background and Purpose: Given the recent rise in cannabis legalization, accessibility and consumption by pregnant individuals, there are unintended developmental consequences considering the key role that the endocannabinoid system plays in fetal development and later-life energy homeostasis. Whether perinatal cannabis exposure (PCE) affects energy homeostasis positively or adversely in adulthood is unknown. We explored the long-term effects of maternal voluntary oral cannabis consumption on the metabolic outcomes of high fat diet (HFD) in adult offspring. Experimental Approach: Pregnant mice voluntarily consumed cannabis from gestational day 1.5 until postnatal day (PD) 10. Pregnancy and pup outcomes and active maternal behavior were recorded. Male and female offspring (PD49) were placed on a 12-week HFD or control diet; their weight gain, adiposity, glucose tolerance, insulin sensitivity, circulating hormones, and pancreas structure were measured. Key Results: PCE pup weight was reduced but was restored by PD16. PCE did not influence weight gain or metabolic characteristics of male mice on a HFD. However, PCE female offspring on a HFD had reduced accumulation of adipose tissue and lower insulin, leptin, and resistin independent of body weight and while PCE females on control diet showed altered basal insulin sensitivity likely due to increased glucagon levels in parallel with reduced islets of Langerhans size and enhanced gene expression of cannabinoid 2 receptors in white adipose tissue. Conclusion and Implications: PCE influences metabolic outcomes in female offspring; it adversely affected glycemic control in female offspring on control diet while it mitigated HFD-induced metabolic dysfunction. This raises concerns about the long-term effects of PCE on the metabolic health of offspring.

The orbitofrontal cortex (OFC) is a key node in the cortico-limbic-striatal circuitry that influences decision-making guided by the relative value of outcomes. Midbrain dopamine from either the ventral tegmental area (VTA) or the dorsal raphe nucleus (DRN) has the potential to modulate OFC neurons, however it is unknown at what concentrations these terminals release dopamine. Male and female adult DATIRES-CRE-tdTomato mice were injected with AAV2/8-EF1a-DIO-eYFP into either the DRN or VTA or the retrograde label CTB 488 in the medial or lateral OFC. We quantified co-expression of CTB 488 or eYFP with tdTomato fluorescence in VTA or DRN as well as eYFP fiber density in the medial or lateral OFC. Both VTA and DRN dopamine neurons project to either the medial or lateral OFC, with greater expression of fibers in the medial OFC. Using fast-scan cyclic voltammetry, we detected optogenetically evoked dopamine from channelrhodopsin2 (ChR2)-expressing VTA or DRN dopamine terminals in either the medial or lateral OFC. Consistent with increased fiber expression in the medial OFC, dopamine was more reliably detected in this region from optical stimulation of VTA or DRN dopamine terminals. We assessed if optical stimulation of dopamine from the VTA or DRN onto the medial OFC could alter layer V pyramidal neuronal firing; however, we did not observe a change in firing at stimulation parameters which evoked dopamine release from either projection. In summary, dopaminergic neurons from the VTA or DRN project to the OFC and release submicromolar dopamine in the medial and lateral OFC.