Estelle Barbier1, Riccardo Barchiesi2, Ana Domi3, Kanat Chanthongdee4, Esi Domi2, Gaelle Augier2, Eric Augier2, Li Xu5, Louise Adermark3, Markus Heilig2. 1. Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden. Electronic address: estelle.barbier@liu.se. 2. Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden. 3. Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. 4. Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Physiology, Faculty of Medicine Siraj Hospital, Mahidol University, Bangkok, Thailand. 5. Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Psychosomatic Medicine Center, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, China.
Abstract
BACKGROUND: Alcohol addiction is characterized by persistent neuroadaptations in brain structures involved in motivation, emotion, and decision making, including the medial prefrontal cortex, the nucleus accumbens, and the amygdala. We previously reported that induction of alcohol dependence was associated with long-term changes in the expression of genes involved in neurotransmitter release. Specifically, Syt1, which plays a key role in neurotransmitter release and neuronal functions, was downregulated. Here, we therefore examined the role of Syt1 in alcohol-associated behaviors in rats. METHODS: We evaluated the effect of Syt1 downregulation using an adeno-associated virus (AAV) containing a short hairpin RNA against Syt1. Cre-dependent Syt1 was also used in combination with an rAAV2 retro-Cre virus to assess circuit-specific effects of Syt1 knockdown (KD). RESULTS: Alcohol-induced downregulation of Syt1 is specific to the prelimbic cortex (PL), and KD of Syt1 in the PL resulted in escalated alcohol consumption, increased motivation to consume alcohol, and increased alcohol drinking despite negative consequences ("compulsivity"). Syt1 KD in the PL altered the excitation/inhibition balance in the basolateral amygdala, while the nucleus accumbens core was unaffected. Accordingly, a projection-specific Syt1 KD in the PL-basolateral amygdala projection was sufficient to increase compulsive alcohol drinking, while a KD of Syt1 restricted to PL-nucleus accumbens core projecting neurons had no effect on tested alcohol-related behaviors. CONCLUSIONS: Together, these data suggest that dysregulation of Syt1 is an important mechanism in long-term neuroadaptations observed after a history of alcohol dependence, and that Syt1 regulates alcohol-related behaviors in part by affecting a PL-basolateral amygdala brain circuit.
BACKGROUND: Alcohol addiction is characterized by persistent neuroadaptations in brain structures involved in motivation, emotion, and decision making, including the medial prefrontal cortex, the nucleus accumbens, and the amygdala. We previously reported that induction of alcohol dependence was associated with long-term changes in the expression of genes involved in neurotransmitter release. Specifically, Syt1, which plays a key role in neurotransmitter release and neuronal functions, was downregulated. Here, we therefore examined the role of Syt1 in alcohol-associated behaviors in rats. METHODS: We evaluated the effect of Syt1 downregulation using an adeno-associated virus (AAV) containing a short hairpin RNA against Syt1. Cre-dependent Syt1 was also used in combination with an rAAV2 retro-Cre virus to assess circuit-specific effects of Syt1 knockdown (KD). RESULTS: Alcohol-induced downregulation of Syt1 is specific to the prelimbic cortex (PL), and KD of Syt1 in the PL resulted in escalated alcohol consumption, increased motivation to consume alcohol, and increased alcohol drinking despite negative consequences ("compulsivity"). Syt1 KD in the PL altered the excitation/inhibition balance in the basolateral amygdala, while the nucleus accumbens core was unaffected. Accordingly, a projection-specific Syt1 KD in the PL-basolateral amygdala projection was sufficient to increase compulsive alcohol drinking, while a KD of Syt1 restricted to PL-nucleus accumbens core projecting neurons had no effect on tested alcohol-related behaviors. CONCLUSIONS: Together, these data suggest that dysregulation of Syt1 is an important mechanism in long-term neuroadaptations observed after a history of alcohol dependence, and that Syt1 regulates alcohol-related behaviors in part by affecting a PL-basolateral amygdala brain circuit.
Authors: Nicholas M Timme; Baofeng Ma; David Linsenbardt; Ethan Cornwell; Taylor Galbari; Christopher C Lapish Journal: Nat Commun Date: 2022-07-09 Impact factor: 17.694