Lieu : Centre Broca Nouvelle-Aquitaine
Invitée par Guillaume Ferreira
The orbitofrontal cortex (OFC) receives sensory information about food and integrates these signals with expected outcomes. Thus, the OFC registers the current value of foods and updates actions based on this information. OFC lesions in animals show a lack of food devaluation. Interestingly, obese humans and rats fed a cafeteria diet have impaired devaluation of food rewards, implicating a potential obesity-induced dysfunction the OFC. We will present findings demonstrating that long-term exposure to a palatable diet alters astrocyte modulation of glutamate homeostasis within the OFC, resulting in enhanced endocannabinoid signalling and tone via Group 1 mGluR activation, which then leads to decreased GABAergic synaptic transmission. We will also present data showing impaired reward devaluation in obese rodents and that this can be restored by increasing GABAergic tone in the OFC. Together these results suggest that obesogenic diets disrupt synaptic transmission in the OFC, which may influence cognitive and emotional processing of decision-making in obesity.
Naef L, Seabrook L, Hsiao J, Li C, Borgland SL (2019). Insulin in the ventral tegmental area reduces cocaine-evoked dopamine in the nucleus accumbens in vivo. Eur J Neurosci. in press
Balsevich G, Sticht M, Bowles NP, Singh A, Lee TTY, Li Z, Chelikani PK, Lee FS, Borgland SL, Hillard CJ, McEwen BS, Hill MN (2018). Role for fatty acid amide hydrolase (FAAH) in the leptin-mediated effects on feeding and energy balance. Proc Natl Acad Sci U S A. 115(29):7605-7610.
Mills F, Globa AK, Liu S, Cowan CM, Mobasser M, Phillips AG, Borgland SL, Bamji SX (2017). Cadherins mediate cocaine-induced synaptic plasticity and behavioral conditioning. Nat Neurosci. 20(4):540-549.
Baimel C, Lau BK, Qiao M, Borgland SL (2017). Projection-Target-Defined Effects of Orexin and Dynorphin on VTA Dopamine Neurons. Cell Rep. 18(6):1346-1355.
Thompson JL, Drysdale M, Baimel C, Kaur M, MacGowan T, Pitman KA, Borgland SL (2017). Obesity-Induced Structural and Neuronal Plasticity in the Lateral Orbitofrontal Cortex. Neuropsychopharmacology 42(7):1480-1490.
Liu S, Globa AK, Mills F, Naef L, Qiao M, Bamji SX, Borgland SL (2016). Consumption of palatable food primes food approach behavior by rapidly increasing synaptic density in the VTA. Proc Natl Acad Sci U S A. 113(9):2520-5.
Thompson JL, Yang J, Lau B, Liu S, Baimel C, Kerr LE, Liu F, Borgland SL (2016). Age-Dependent D1-D2 Receptor Coactivation in the Lateral Orbitofrontal Cortex Potentiates NMDA Receptors and Facilitates Cognitive Flexibility. Cereb Cortex. 26(12):4524-4539.
Baimel C, Borgland SL (2015). Orexin Signaling in the VTA Gates Morphine-Induced Synaptic Plasticity. J Neurosci. 35(18):7295-303